Autor: Julio Cesar Tafforelli | Publicado: 2010-12-28T22:21:00-08:00

The Coherent HeartHeart–Brain Interactions, PsychophysiologicalCoherence, and the Emergence of System-Wide OrderRollin McCraty, Ph.D., Mike Atkinson, Dana Tomasino, B.A.,and Raymond Trevor Bradley, Ph.D.1Abstract: This article presents theory and research on the scientific study of emotion thatemphasizes the importance of coherence as an optimal psychophysiological state. Adynamic systems view of the interrelations between psychological, cognitive andemotional systems and neural communication networks in the human organism providesa foundation for the view presented. These communication networks are examined froman information processing perspective and reveal a fundamental order in heart-braininteractions and a harmonious synchronization of physiological systems associated withpositive emotions. The concept of coherence is drawn on to understand optimalfunctioning which is naturally reflected in the heart’s rhythmic patterns. Research ispresented identifying various psychophysiological states linked to these patterns, withneurocardiological coherence emerging as having significant impacts on well being.These include psychophysiological as well as improved cognitive performance. Fromthis, the central role of the heart is explored in terms of biochemical, biophysical andenergetic interactions. Appendices provide further details and research on;psychophysiological functioning, reference previous research in this area, details onresearch linking coherence with optimal cognitive performance, heart brainsynchronization and the energetic signature of the various psychophysiological modes.Keywords: Cognitive performance, coherence, emotion, heart rate variability, heart-braininteractions, neurocardiology, psychophysiological coherence, quantum holographicprinciples.This volume draws on the basic research conducted over the last decade at the Institute of HeartMath byDr. Rollin McCraty and Mike Atkinson. The original manuscript for this article was drafted between 1998and 2003 by Rollin McCraty and Dana Tomasino. Mike Atkinson conducted the analysis of the researchreported here and also constructed the figures and graphs displaying the statistical information. Dr.Raymond Bradley joined the project in 2004 to work on a major revision and expansion of the manuscriptto help bring the article to its present form.Correspondence should be directed to Dr. Rollin McCraty, Director of Research, HeartMath ResearchCenter.14700 West Park AvenueBoulder Creek, California 95006Office: 831-338-8727rollin@heartmath.orgINTEGRAL REVIEWDecember 2009Vol. 5, No. 2Prologue ................................................................................................................................... 13 Introduction .............................................................................................................................. 14 Theoretical Considerations ...................................................................................................... 16 Conceptual Framework ........................................................................................................ 16 Information and Communication ..................................................................................... 16 The Concept of Coherence ............................................................................................... 17 Theory .................................................................................................................................. 18 The Psychophysiological Network: A Systems Perspective.................................................... 19 Heart Rate Variability and Measurement of Psychophysiological Modes .......................... 20 Emotions and Heart Rhythm Patterns .................................................................................. 20 Psychophysiological Coherence .......................................................................................... 22 Heart Rhythm Coherence ................................................................................................. 23 Physiological Correlates................................................................................................... 23 Psychological and Behavioral Correlates......................................................................... 26 Drivers of Coherence ....................................................................................................... 26 Benefits of Psychophysiological Coherence .................................................................... 27 A Typology of Psychophysiological Interaction.................................................................. 28 Psychophysiological Hyper-States ................................................................................... 32 Heart Coherence and Psychophysiological Function............................................................... 34 Vagal Afferent Traffic.......................................................................................................... 35 Pain Perception .................................................................................................................... 36 Respiration ........................................................................................................................... 36 Emotional Processing ........................................................................................................... 38 Coherence and Cognitive Performance.................................................................................... 41 The Heart Rhythm Coherence Hypothesis: A Macro-Scale Perspective ............................. 42 A More Complex Picture ..................................................................................................... 43 Complexity of Cardiac Afferent Signals .......................................................................... 43 Afferent Input to Brain Centers other than the Thalamus ................................................ 44 Heart–Brain Synchronization ........................................................................................... 45 System Dynamics: Centrality of the Heart in the Psychophysiological Network ................... 45 A Systems Approach ............................................................................................................ 46 Neurological Interactions ..................................................................................................... 47 Coherence Within the Brain ............................................................................................. 47 More Than a Pump ........................................................................................................... 50 Biochemical Interactions...................................................................................................... 51 Biophysical Interactions ....................................................................................................... 54 Energetic Interactions........................................................................................................... 55 Energetic Signatures of Psychophysiological Modes .......................................................... 56 The Holographic Heart ......................................................................................................... 56 Conclusion ............................................................................................................................... 58 References ................................................................................................................................ 61 wholesocialscience@sbcglobal.net Appendixes ...................................................................... 73 Appendixes............................................................................................................................... 73 Appendix A: Modes of Psychophysiological Function ........................................................... 73 INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Modes of Everyday Psychophysiological Function ............................................................. 76 Mental Focus .................................................................................................................... 76 Psychophysiological Incoherence .................................................................................... 77 Relaxation ........................................................................................................................ 77 Psychophysiological Coherence ...................................................................................... 78 Modes Distinguished by Low Variability ............................................................................ 79 Emotional Quiescence...................................................................................................... 80 Extreme Negative Emotion .............................................................................................. 81 Appendix B: Previous Research............................................................................................... 84 The Baroreceptor Hypothesis: A Micro-Scale Perspective ................................................. 84 Appendix C: Research on Coherence and Cognitive Performance ......................................... 88 HeartMath Institute Research............................................................................................... 88 UK Research ........................................................................................................................ 90 HeartMath’s TestEdge Program on Test Anxiety and Performance .................................... 94 Appendix D: Heart Brain Synchronization ............................................................................ 101 Appendix E: Energetic Signatures of Psychophysiological Modes ....................................... 109 Mental Focus .................................................................................................................. 109 Psychophysiological Incoherence .................................................................................. 110 Extreme Negative Emotion ............................................................................................ 111 Relaxation ...................................................................................................................... 112 Psychophysiological Coherence .................................................................................... 113 Emotional Quiescence.................................................................................................... 114 INTEGRAL REVIEWDecember 2009Vol. 5, No. 2…there are organism states in which the regulation of life processes becomes efficient, oreven optimal, free-flowing and easy. This is a well established physiological fact. It is not ahypothesis. The feelings that usually accompany such physiologically conducive states aredeemed “positive,” characterized not just by absence of pain but by varieties of pleasure.There also are organism states in which life processes struggle for balance and can evenbe chaotically out of control. The feelings that usually accompany such states are deemed“negative,” characterized not just by absence of pleasure but by varieties of pain. … Thefact that we, sentient and sophisticated creatures, call certain feelings positive and otherfeelings negative is directly related to the fluidity or strain of the life process.(Damasio, 2003, p. 131)Chris, a 45-year-old business executive, had a family history of heart disease, and wasfeeling extremely stressed, fatigued, and generally in poor emotional health. A 24-hourheart rate variability analysis3 revealed abnormally depressed activity in both branches ofhis autonomic nervous system, suggesting autonomic exhaustion ensuing frommaladaptation to high stress levels. His heart rate variability was far lower then would beexpected for his age, and was below the clinical cut-off level for significantly increasedrisk of sudden cardiac death. In addition, Chris’s average heart rate was abnormally highat 102 beats per minute, and his heart rate did not drop at night as it should.Upon reviewing these results, his physician concluded that it was imperative that Christake measures to reduce his stress. He recommended that Chris begin practicing a systemof emotional restructuring techniques that had been developed by the Institute ofHeartMath. These positive emotion-focused techniques help individuals learn to self-generate and sustain a beneficial functional mode known as psychophysiologicalcoherence, characterized by increased emotional stability and by increasedsynchronization and harmony in the functioning of physiological systems.Concerned about his deteriorating health, Chris complied with his physician’srecommendation. Each morning during his daily train commute to work, he practiced theHeart Lock-In technique, and he would use the Freeze-Frame technique in situations whenhe felt his stress levels rise.4Excerpted from McCraty & Tomasino (2006), pp. 360-361.The analysis of heart rate variability (HRV), a measure of the naturally occurring beat-to-beat changes inheart rate, provides an indicator of neurocardiac fitness and autonomic nervous system function.Abnormally low 24-hour HRV is predictive of increased risk of heart disease and premature mortality.HRV is also highly reflective of stress and emotions.4The Heart Lock-In tool is an emotional restructuring technique, generally practiced for 5 to 15 minutes,that helps build the capacity to sustain the psychophysiological coherence mode for extended periods oftime. The Freeze-Frame technique is a one-minute positive emotion refocusing exercise used in themoment that stress is experienced to change perception and modify the psychophysiological stressresponse. For in-depth descriptions of these techniques, see Childre & Martin (1999) and Childre &Rozman (2005).INTEGRAL REVIEWDecember 2009Vol. 5, No. 2At first Chris was not aware of the transformation that was occurring. His wife was thefirst to notice the change and to remark about how differently he was behaving and howmuch better he looked. Then his co-workers, staff, and other friends began to comment onhow much less stressed he appeared in responding to situations at work and how muchmore poise and emotional balance he had. A second autonomic nervous systemassessment, performed six weeks after the initial one, showed that Chris’s average heartrate had decreased to 85 beats per minute and it now lowered at night, as it should.Significant increases were also apparent in his heart rate variability, which had more thandoubled! These results surprised Chris’ physician, as 24-hour heart rate variability istypically very stable from week to week, and it is generally quite difficult to recover fromautonomic nervous system depletion, usually requiring much longer than six weeks.In reflecting on his experience, Chris started to see how profoundly his health and his lifehad been transformed. He was getting along with his family, colleagues, and staff betterthan he could remember ever having enjoyed before, and he felt much more clearheadedand in command of his life. His life seemed more harmonious, and the difficulties thatcame up at work and in his personal relationships no longer created the same level ofdistress; he now found himself able approach them more smoothly and proactively, andoften with a broadened perspective.The true story of Chris’s transformation is not an isolated example, but rather is only one ofmany similar case histories that people like Chris have shared with HeartMath, illustrating theamazing transformations that can occur when one learns how to increase psychophysiologicalcoherence.Many contemporary scientists believe that the quality of feeling and emotion we experience ineach moment is rooted in the underlying state of our physiological processes. This view is wellexpressed by neuroscientist Antonio Damasio in the epigram that opened this article. Theessence of his idea is that we call certain emotional feelings “positive” and others “negative”because these experiences directly reflect the impact of the “fluidity or strain of the life process”on the body, as is clearly evident in Chris’ case, above. The feelings we experience as “negative”are indicative of body states in which “life processes struggle for balance and can even bechaotically out of control” (Damasio, 2003, p. 131). By contrast, the feelings we experience as“positive” actually reflect body states in which “the regulation of life processes becomesefficient, or even optimal, free-flowing and easy” (Damasio, p. 131).While there is a growing appreciation of this general understanding in the scientific study ofemotion, here we seek to deepen this understanding in three primary ways. First, our approach isbased on the premise that the physiological, cognitive, and emotional systems are intimatelyinterrelated through ongoing reciprocal communication. To obtain a deeper understanding of theoperation of any of these systems, we believe it is necessary to view their activity as emergentfrom the dynamic, communicative network of interacting functions that comprise the humanorganism. Second, we adopt an information processing perspective, which views communicationwithin and among the body’s systems as occurring through the generation and transmission ofINTEGRAL REVIEWDecember 2009Vol. 5, No. 2rhythms and patterns of psychophysiological activity. This points to a fundamental order ofinformation communication—one that both signifies different emotional states, operates tointegrate and coordinate the body’s functioning as a whole, and also connects the body to theexternal world. And third, we draw on the concept of coherence from the physics of signalprocessing to understand how different patterns of psychophysiological activity influence bodilyfunction. Efficient or optimal function is known to result from a harmonious organization of theinteraction among the elements of a system. Thus, a harmonious order in the rhythm or pattern ofpsychophysiological activity signifies a coherent system, whose efficient or optimal function isdirectly related, in Damasio’s terms, to the ease and “fluidity” of life processes. By contrast, anerratic, discordant pattern of activity denotes an incoherent system, whose function reflects thedifficulty and “strain” of life processes.In this article we explore the concept and meaning of coherence in variouspsychophysiological contexts and describe how coherence within and among the physiological,cognitive, and emotional systems is critical in the creation and maintenance of health, emotionalstability, and optimal performance. It is our thesis that what we call emotional coherence—aharmonious state of sustained, self-modulated positive emotion—is a primary driver of thebeneficial changes in physiological function that produce improved performance and overallwell-being. We also propose that the heart, as the most powerful generator of rhythmicinformation patterns in the body, acts effectively as the global conductor in the body’s symphonyto bind and synchronize the entire system. The consistent and pervasive influence of the heart’srhythmic patterns on the brain and body not only affects our physical health, but alsosignificantly influences perceptual processing, emotional experience, and intentional behavior.There is abundant evidence that emotions alter the activity of the body’s physiologicalsystems. Yet the vast majority of this scientific evidence concerns the effects of negativeemotions. More recently, researchers have begun to investigate the functions and effects ofpositive emotions. This research has shown that, beyond their pleasant subjective feeling,positive emotions and attitudes have a number of objective, interrelated benefits forphysiological, psychological, and social functioning (Fredrickson, 2002; Isen, 1999).In contributing to this work, we discuss how sustained positive emotions facilitate anemergent global shift in psychophysiological functioning, which is marked by a distinct changein the rhythm of heart activity. This global shift generates a state of optimal function,characterized by increased synchronization, harmony, and efficiency in the interactions withinand among the physiological, cognitive, and emotional systems. We call this statepsychophysiological coherence. We describe how the coherence state can be objectivelymeasured and explore the nature and implications of its physiological and psychologicalcorrelates. It is proposed that the global synchronization and harmony generated in the coherencestate may explain many of the reported psychological and physiological health benefitsassociated with positive emotions.Our discussion of the major pathways by which the heart communicates with the brain andbody shows how signals generated by the heart continually inform emotional experience andinfluence cognitive function. This account includes a review of previous research on heart–braininteractions and theories regarding how the activity of the heart affects brain function andINTEGRAL REVIEWDecember 2009Vol. 5, No. 2cognitive performance. We then present research conducted in our laboratory, which brings anew perspective, focusing on the pattern of the rhythm of heart activity and its relationship toemotional experience. From this vantage point, we derive a new hypothesis—that sustained, self-induced positive emotions generate a shift to a state of system-wide coherence in bodilyprocesses, in which the coherent pattern of the heart’s rhythm plays a key role in facilitatinghigher cognitive functions.In short, the science reviewed in this article shows that through regular heart-based practice, itis possible to use positive emotions to shift one’s whole psychophysiological system into a stateof global coherence. When sustained, the harmonious order of coherence generates vital benefitson all levels and can even transform an individual’s life, as we saw in the prologue describingChris’s story.Theoretical ConsiderationsWe begin by introducing the basic concepts and theoretical ideas that inform the materialpresented in this article.Integral to the understanding of psychophysiological interaction developed in this work arethe concepts of information and communication. As we will see next, coherence is a particularquality that emerges from the relations among the parts of a system or from the relations amongmultiple systems. And since relations are constitutive of systems, the communication ofinformation plays a fundamental constructive role in the generation and emergence of coherence.Although the communication of information is largely implicit in the interactional basis of thethree basic concepts of coherence we begin with in this conceptual framework, we go ontodevelop a detailed account of the nature, substance, and dynamics of the psychophysiologicalinteractions between the heart, the brain, and the body as a whole.Information and CommunicationThe most basic definition of information is data which in-form, or give shape to, action orbehavior, such as a message that conveys “meaning” to the recipient of a signal (Bradley &Pribram, 1998). In human language, abstract symbols like words, numbers, graphical figures, andeven gestures and vocal intonations are used to encode the meaning conveyed in a message. Inphysiological systems, changes in chemical concentrations, the amount of biological activity, orthe pattern of rhythmic activity are common means by which information is encoded in themovement of energy to inform system behavior.But in order to be used to shape or regulate system behavior, the information must bedistributed to and “understood” by the system elements involved. Thus, by communication wemean a process by which meaning is encoded as a message and transmitted in a signal to bereceived, processed, and comprehended by the various elements of a system.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2In this article we describe the relationship between different patterns of psychophysiologicalactivity and physiological, emotional and cognitive functions by drawing on three distinct butrelated concepts of coherence used in physics; global coherence, cross coherence and auto-coherence. The most common definition of coherence is "the quality of being logicallyintegrated, consistent and intelligible," as in a coherent argument. A related meaning is "alogical, orderly and aesthetically consistent relationship of parts" (McCraty & Tomasino, 2006,p. 4). In the following discussion we delve deeper into the meaning of coherence.Coherence in ordinary language means correlation, a sticking together, or connectedness;also, a consistency in the system. So we refer to people's speech or thought as coherent, if theparts fit together well, and incoherent if they are uttering meaningless nonsense, or presentingideas that don't make sense as a whole (Ho, 1998). Thus, coherence in this context refers towholeness and a global order: This is coherence as a distinctive organization of parts, therelations among which generate an emergent whole that is greater than the sum of the individualparts. In the example of organizing words in a coherent sentence, the meaning and purposeconveyed by the arrangement of the words is greater than the individual meaning of each word.It is important to note that all systems, to produce any function or action, must have theproperty of global coherence. The efficiency and effectiveness of the function or action can varywidely, however, and therefore does not necessarily result in a coherent flow of behavior. Globalcoherence does not mean that everybody or all the parts are doing the same thing at the sametime. Think of a jazz band for example, where the individual players are each doing his or herown thing, yet keeping in tune and step with the whole band. Coherence in this sense maximizeslocal freedom and global cohesion and resonance with the musical theme (Ho, 1998).In a living system global order or coherence must be sustained and maintained over time. Forexample, biochemist and geneticist Mae-Wan Ho (1998) has suggested that a whole livingsystem is a domain of coherent, autonomous activity that is coordinated across a continuum fromthe molecular to macroscopic to social levels.In physics, the concept of coherence is also used to describe the interaction or couplingamong different oscillating systems in which synchronization is the key idea in this concept.Synchronization describes the degree to which two or more waves are either phase or frequency-locked together, or when communication occurs between systems or modes without obstruction.Returning to the music example, a chord is composed of notes of different frequencies yetresonate as a harmonious order of sound waves. In physiology, coherence is similarly used todescribe the degree of coupling and harmonious interaction between two or more of the body'soscillatory systems such as respiration and heart rhythms. There are modes where they areoperating at different frequencies, and modes when they become entrained and oscillate at thesame frequency. This is also true for brain states in which the brainwaves can be momentarily inphase at different locations across the brain. The term cross-coherence is used to specify thistype aspect of coherence.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Another example, from a physiological systems perspective, is that people's thoughts,emotions and attitudes can either be aligned and coherent or incoherent. When individuals thinkone way, feel another, and behave inconsistently, they are in an inefficient and ineffective state-that's non-coherence. A situation adults commonly face illustrates another kind of incoherence.For example, if a child has hit another child and must be taught to be kind to others and thathitting is not acceptable, consider the internal state of an adult in the following two scenarios:1. The adult who punishes the child with a spanking for hitting another child.2. The adult who takes time to teach and encourage the child to apologize and render an actof service or kindness to the other child. In this instance, the thoughts, feelings and actionsof the adult are in coherent alignment with the message being taught. Then the child ismore likely to have a coherent understanding of the lesson being taught.Another aspect of coherence relates to the dynamics of the flow of action produced by asingle system (McCraty & Tomasino, 2006). This is coherence as a uniform pattern of cyclicalbehavior. Because this pattern of action is generated by a single system, the term auto-coherenceis used to denote this type of coherence. This concept is commonly used in physics to describethe generation of an ordered distribution of energy in a waveform. An example is a sine wave,which is a perfectly coherent wave. The more stable the frequency, amplitude, and shape of thewaveform, the higher the degree of coherence. In physiological systems, this type of coherencedescribes the degree of order and stability in the rhythmic activity generated by a singleoscillatory such as the hearts rhythmic activity. When coherence is increased in a single systemthat is coupled to other systems, it can pull the other systems into coherence or entrainment,resulting in increased cross-coherence in the activity of the other systems, even across differenttime scales of activity. An example of this is in the increased heart-brain synchronization thatoccurs in a heart coherent mode.The material presented in this article is informed by the following theoretical considerations.Our psychophysiological systems process an enormous amount of information, which must becontinuously communicated from one part of the brain or body to another and often stored as amemory of one type or another. The traditional approach to understanding how the body’ssystems interact adopts an activation perspective, in which variation in the amount of a substanceor the amount of a given physiological activity is viewed as the basis of communication.Although the amount of activity is clearly an important aspect of communication, the generationand transmission of rhythms and patterns of physiological activity appear reflective of a morefundamental order of information communication—one that signifies different emotional statesand operates to integrate and coordinate the body’s functioning as a whole.Throughout the body, information is encoded in waveforms of energy as patterns ofphysiological activity. Neural, chemical, electromagnetic, and oscillatory pressure wave patternsare among those used to encode and communicate biologically relevant information. By thesemeans, the body’s organs continually transmit information to the brain as patterns of afferent(ascending) input. In turn, as we will see below, changes in the patterns of afferent input to theINTEGRAL REVIEWDecember 2009Vol. 5, No. 2brain cause significant changes in physiological function, perception, cognition, emotion, andintentional behavior.A primary proposition explored in this article is that different emotions are associated withdistinct patterns of physiological activity. This is the result of a two-way process by which, inone direction, emotions trigger changes in the autonomic nervous system and hormonal system,and in the other direction, specific changes in the physiological substratum are involved in thegeneration of emotional experience. Research at the Institute of HeartMath has identified sixdistinct patterns of physiological activity generated during different emotional states. We callthese psychophysiological modes. Each of these is described in detail in Appendix A. Ofparticular significance is the psychophysiological coherence mode, which is characterized byordered, harmonious patterns of physiological activity. This mode has been found to begenerated during the experience of sustained positive emotions. The psychophysiologicalcoherence mode has numerous physiological and psychological benefits, which can profoundlyimpact health, performance, and quality of life.A second proposition is that the heart plays a central role in the generation and transmissionof system-wide information essential to the body’s function as a coherent whole. There aremultiple lines of evidence to support this proposition: The heart is the most consistent anddynamic generator of rhythmic information patterns in the body; its intrinsic nervous system is asophisticated information encoding and processing center that operates independently of thebrain; the heart functions in multiple body systems and is thus uniquely positioned to integrateand communicate information across systems and throughout the body; and, of all the bodilyorgans, the heart possesses by far the most extensive communication network with the brain. Asdescribed subsequently, afferent input from the heart not only affects the homeostatic regulatorycenters in the brain, but also influences the activity of higher brain centers involved inperceptual, cognitive, and emotional processing, thus in turn affecting many and diverse aspectsof our experience and behavior. These are the central ideas that guide what follows.The Psychophysiological Network: A Systems PerspectiveAs science has increasingly adopted a systems perspective in investigation and analysis, theunderstanding has emerged that our mental and emotional functions stem from the activity ofsystems—organized pathways interconnecting different organs and areas of the brain and body—just as do any of our physiological functions. Moreover, our mental and emotional systemscannot be considered in isolation from our physiology. Instead, they must be viewed as anintegral part of the dynamic, communicative network of interacting functions that comprise thehuman organism.These understandings have led to the emergence and growth of new scientific fields of study,such as psychophysiology. Psychophysiology is concerned with the interrelations among thephysiological, cognitive, and emotional systems and human behavior. It is now evident thatevery thought, attitude, and emotion has a physiological consequence, and that patterns ofphysiological activity continually influence our emotional experience, thought processes, andbehavior. As we will see shortly, the efficacy of this perspective has been substantiated by ourINTEGRAL REVIEWDecember 2009Vol. 5, No. 2own research, as well as that of many others, examining how patterns of psychophysiologicalactivity change during stress and different emotional states.Heart Rate Variability and Measurement of Psychophysiological ModesIn the early stages of our work at the Institute of HeartMath, we sought to determine whichphysiological variables were most sensitive to and correlated with changes in emotional states. Inanalyzing many different physiological measures (such as heart rate, electroencephalographicand electromyographic activity, respiration, skin conductance, etc.), we discovered that therhythmic pattern of heart activity was directly associated with the subjective activation ofdistinct emotional states, and that the heart rhythm pattern also reflected changes in emotionalstates, in that it covaried with emotions in real time. We found strong differences between quitedistinct rhythmic beating patterns that were readily apparent in the heart rhythm trace and thatdirectly matched the subjective experience of different emotions. In short, we found that thepattern of the heart’s activity was a valid physiological indicator of emotional experience andthat this indicator was reliable when repeated at different times and in different populations.In more specific terms, we examined the natural fluctuations in heart rate, known as heart ratevariability (HRV). HRV is a product of the dynamic interplay of many of the body’s systems.Short-term (beat-to-beat) changes in heart rate are largely generated and amplified by theinteraction between the heart and brain. This interaction is mediated by the flow of neural signalsthrough the efferent and afferent pathways of the sympathetic and parasympathetic branches ofthe autonomic nervous system (ANS). HRV is thus considered a measure of neurocardiacfunction that reflects heart–brain interactions and ANS dynamics.From an activation theory perspective, the focus is on changes in heart rate or in the amountof variability that are expected to be associated with different emotional states. However, whilethese factors can and often do covary with emotions, we have found that it is the pattern of theheart’s rhythm that is primarily reflective of the emotional state. Furthermore, we have foundthat changes in the heart rhythm pattern are independent of heart rate: one can have a coherent orincoherent pattern at high or low heart rates. Thus, it is the rhythm, rather than the rate, that ismost directly related to emotional dynamics and physiological synchronization.Emotions and Heart Rhythm PatternsAs mentioned at the outset, researchers have spent much time and effort investigating howemotions change the state and functioning of the body’s systems. While the vast majority of thisbody of work has focused on understanding the pathological effects of negative emotions, recentresearch has begun to balance this picture by investigating the functions and effects of positiveemotions.A synthesis of the voluminous work in developmental neurobiology has shown that themodulation of positive emotions plays a critical role in infant growth and neurologicaldevelopment, which has enormous consequences for later life (Schore, 1994). Other research onadults has documented a wide array of effects of positive emotions on cognitive processing,behavior, and health and well-being. Positive emotions have been found to broaden the scope ofINTEGRAL REVIEWDecember 2009Vol. 5, No. 2perception, cognition, and behavior (Fredrickson, 2001, 2005; Isen, 1999), thus enhancingfaculties such as creativity (Isen, 1998) and intuition (Bolte, Goschke, & Kuhl, 2003). Moreover,the experience of frequent positive emotions has been shown to predict resilience andpsychological growth, (Fredrickson, Tugade, Waugh, & Larkin, 2003) while an impressive bodyof research has documented clear links between positive emotions, health status, and longevity(Blakeslee & Grossarth-Maticek, 1996; Danner, Snowdon, & Friesen, 2001; Medalie &Goldbourt, 1976; Moskowitz, 2003; Ostir, Markides, Black, & Goodwin, 2000; Ostir, Markides,Peek, & Goodwin, 2001; Russek & Schwartz, 1997; Seeman & Syme, 1987). In addition, there isabundant evidence that positive emotions affect the activity of the body’s physiological systemsin profound ways. For instance, studies have shown that positive emotional states speed therecovery of the cardiovascular system from the after-effects of negative emotions (Fredrickson etal., 2000), alter frontal brain asymmetry (Davidson et al., 2003), and increase immunity(Davidson et al.; McCraty, Atkinson, Rein, & Watkins, 1996; Rein, Atkinson, & McCraty,1995). Finally, the use of practical techniques that teach people how to self-induce and sustainpositive emotions and attitudes for longer periods has been shown to produce positive healthoutcomes. These include reduced blood pressure in both hypertensive and normal populations,(McCraty, Atkinson, Lipsenthal, et al., 2003; McCraty, Atkinson, & Tomasino, 2003) improvedfunctional capacity in patients with heart failure (Luskin, Reitz, Newell, Quinn, & Haskell,2002), improved hormonal balance, (McCraty, Barrios-Choplin, Rozman, Atkinson, & Watkins,1998) and lower lipid levels (McCraty, Atkinson, Lipsenthal, et al., 2003).In investigating the physiological foundation of this important work, we have utilized HRVanalysis to show how distinct heart rhythm patterns characterize different emotional states. Inmore specific terms, we found that underlying the experience of different emotional states thereis a distinct physiology directly involved. Thus we have found that sustained positive emotionssuch as appreciation, care, compassion, and love generate a smooth, sine-wave-like pattern in theheart’s rhythms. This reflects increased order in higher-level control systems in the brain,increased synchronization between the two branches of the ANS, and a general shift inautonomic balance towards increased parasympathetic activity. As is visually evident (Figure 1)and also demonstrable by quantitative methods, heart rhythms associated with positive emotions,such as appreciation, are clearly more coherent—organized as a stable pattern of repeating sinewaves—than those generated during a negative emotional experience such as frustration. Weobserved that this association between positive emotional experience and this distinctivephysiological pattern was evident in studies conducted in both laboratory and natural settings,and for both spontaneous emotions and intentionally generated feelings (McCraty, Atkinson,Tiller, Rein, & Watkins, 1995; Tiller, McCraty, & Atkinson, 1996).By contrast, our research has shown that negative emotions such as frustration, anger, anxiety,and worry lead to heart rhythm patterns that appear incoherent—highly variable and erratic.Overall, this means that there is less synchronization in the reciprocal action of theparasympathetic and sympathetic branches of the ANS (McCraty et al., 1995; Tiller et al., 1996).This desynchronization in the ANS, if sustained, taxes the nervous system and bodily organs,impeding the efficient synchronization and flow of information throughout thepsychophysiological systems. Furthermore, as studies have also shown that prefrontal cortexactivity is reflected in HRV via modulation of the parasympathetic branch of the ANS (Lane,INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Reiman, Ahern, & Thayer, 2001), this increased disorder in heart rhythm patterns is also likelyindicative of disorder in higher brain systems.Figure 1. Emotions are reflected in heart rhythm patterns. The heart rhythm pattern shown inthe top graph, characterized by its erratic irregular pattern (incoherence), is typical of negativeemotions such as anger or frustration. The bottom graph shows an example of the coherent heartrhythm pattern that is typically observed when an individual is experiencing sustained,modulated positive emotions, in this case appreciation.Psychophysiological CoherenceIn our research on the physiological correlates of positive emotions we have found that whencertain positive emotional states, such as appreciation, compassion, or love, are intentionallymaintained, coherent heart rhythm patterns can be sustained for longer periods, which also leadsto increased synchronization and entrainment between multiple bodily systems. Because it ischaracterized by distinctive psychological and behavioral correlates as well as by specificpatterns of physiological activity throughout the body, we introduced the termpsychophysiological coherence5 to describe this mode of functioning.In earlier publications (Tiller et al., 1996), the psychophysiological coherence mode was referred to asthe “entrainment mode” because a number of physiological systems entrain with the heart rhythm in thismode.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2The development of heart rhythm coherence—a stable, sine-wave-like pattern in the heart ratevariability waveform—is the key marker of the psychophysiological coherence mode. Heartrhythm coherence is reflected in the HRV power spectrum as a large increase in power in the lowfrequency (LF) band (typically around 0.1 Hz) and a decrease in the power in the very lowfrequency (VLF) and high frequency (HF) bands. A coherent heart rhythm can therefore bedefined as a relatively harmonic (sine-wave-like) signal with a very narrow, high-amplitude peakin the LF region of the HRV power spectrum and no major peaks in the VLF or HF regions.Coherence thus approximates the LF/(VLF + HF) ratio. (See Appendix A for an explanation ofthe HRV power spectrum and a description of the physiological significance of the differentfrequency bands.)A method of quantifying heart rhythm coherence is shown in Figure 2. First, the maximumpeak is identified in the 0.04–0.26 Hz range (the frequency range within which coherence andentrainment can occur). The peak power is then determined by calculating the integral in awindow 0.030 Hz wide, centered on the highest peak in that region. The total power of the entirespectrum is then calculated. The coherence ratio is formulated as:(Peak Power / (Total Power − Peak Power)) (Childre & Martin, 1999)This method provides an accurate measure of coherence that allows for the nonlinear nature ofthe HRV waveform over time.Figure 2. Heart rhythm coherence ratio calculation.At the physiological level, psychophysiological coherence embraces several relatedphenomena—autocoherence, entrainment, synchronization, and resonance—which areassociated with increased order, efficiency, and harmony in the functioning of the body’ssystems. As described above, this mode is associated with increased coherence in the heart’sINTEGRAL REVIEWDecember 2009Vol. 5, No. 2rhythmic activity (autocoherence), which reflects increased ANS synchronization and manifestsas a sine-wave-like heart rhythm pattern oscillating at a frequency of approximately 0.1 Hz.Thus, in this mode the HRV power spectrum6 is dominated by a narrow-band, high-amplitudepeak near the center of the low frequency band (see Figures 3 below and 8 in Appendix A)(McCraty et al., 1995; Tiller et al., 1996).Another physiological correlate of the coherence mode is the phenomenon of resonance. Inphysics, resonance refers to a phenomenon whereby an unusually large oscillation is produced inresponse to a stimulus whose frequency is the same as, or nearly the same as, the naturalvibratory frequency of the system. The frequency of the vibration produced in such a state isdefined as the resonant frequency of the system. When the cardiovascular system is operating inthe coherence mode, it is essentially oscillating at its resonant frequency; this is reflected in thedistinctive high-amplitude peak in the HRV power spectrum around 0.1 Hz. Most mathematicalmodels show that the resonant frequency of the human cardiovascular system is determined bythe feedback loops between the heart and brain (Baselli et al., 1994; DeBoer, Karemaker, &Strackee, 1987). In humans and in many animals, the resonant frequency of the system isapproximately 0.1 Hz, which is equivalent to a 10-second rhythm. The system naturallyoscillates at its resonant frequency when an individual is actively feeling a sustained positiveemotion such as appreciation, compassion, or love, (McCraty et al., 1995) although resonancecan also emerge during states of deep sleep.Furthermore, increased heart–brain synchronization is observed during coherence;specifically, the brain’s alpha rhythms exhibit increased synchronization with the heartbeat inthis mode. This finding is discussed in greater depth in Appendix D.Finally, there tends to be increased cross-coherence or entrainment among the rhythmicpatterns of activity generated by different physiological oscillatory systems. Entrainment occurswhen the frequency difference between the oscillations of two or more nonlinear systems dropsto zero by being “frequency pulled” to the frequency of the dominant system. As the body’s mostpowerful rhythmic oscillator, the heart can pull other resonant physiological systems intoentrainment with it. During the psychophysiological coherence mode, entrainment is typicallyobserved between heart rhythms, respiratory rhythms, and blood pressure oscillations; however,other biological oscillators, including very low frequency brain rhythms, craniosacral rhythms,and electrical potentials measured across the skin, can also become entrained (Bradley &Pribram, 1998; Tiller et al., 1996).Figure 3 shows an example of entrainment occurring during psychophysiological coherence.The graphs plot an individual’s heart rhythm, arterial pulse transit time (a measure of beat-to-beat blood pressure) (Bradley & Pribram, 1998), and respiration rate over a 10-minute period. Inthis example, after a 300-second normal resting baseline period the subject used a heart-basedpositive emotion refocusing technique known as Freeze-Frame, (Childre & Martin, 1999) whichSpectral analysis decomposes the HRV waveform into its individual frequency components andquantifies them in terms of their relative intensity using power spectral density (PSD) analysis. Spectralanalysis thus provides a means to quantify the relative activity of the different physiological influences onHRV, which are represented by the individual oscillatory components that make up the heart rhythm.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2involves focusing attention in the area of the heart while self-generating a sincere positiveemotion, such as appreciation. After the subject used the Freeze-Frame technique, the threerhythms shifted from an erratic to a sine-wave-like pattern (indicative of the coherence mode)and all entrained at a frequency of 0.12 Hz. (Tiller et al., 1996). The entrainment phenomenon isthus an example of a psychophysiological state in which there is increased coherence within eachsystem (autocoherence) and among multiple oscillating systems (cross-coherence) as well. Thisexample also illustrates how the intentional generation of a self-regulated positive emotionalstate can bring about a phase-shift in physiological activity, driving the physiological systemsinto a globally coherent mode of function.120180240300360TIME (SECONDS)2520151008.00E-56.00E-54.00E-52.00E-50.00E+00.80.60.40.2420480540600500.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4FREQUENCY00.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4FREQUENCYFigure 3. Entrainment. The top graphs show an individual’s heart rate variability, pulse transittime, and respiration rhythms over a 10-minute period. At the 300-second mark, the individualused the Freeze-Frame positive emotion refocusing technique, causing these three systems tocome into entrainment. The bottom graphs show the frequency spectra of the same data on eachside of the dotted line in the center of the top graph. Notice the graphs on the right show that allthree systems have entrained to the same frequency.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Psychological and Behavioral CorrelatesThe experience of the coherence mode is also qualitatively distinct at the psychological level.This mode is associated with reduced perceptions of stress, sustained positive affect, and a highdegree of mental clarity and emotional stability. In Appendix C we also present data indicatingthat coherence is associated with improved sensory-motor integration, cognition, and taskperformance. In addition, individuals frequently report experiencing a notable reduction ininternal mental dialogue, increased feelings of inner peace and security, more effective decisionmaking, enhanced creativity, and increased intuitive discernment when engaging this mode.In summary, psychophysiological coherence is a distinctive mode of function driven bysustained, modulated positive emotions. At the psychological level, the term “coherence” is usedto denote the high degree of order, harmony, and stability in mental and emotional processes thatis experienced during this mode. Physiologically speaking, “coherence” is used here as a generalterm that encompasses entrainment, resonance, and synchronization—distinct but relatedphenomena, all of which emerge from the harmonious activity and interactions of the body’ssubsystems. Physiological correlates of the coherence mode include: increased synchronizationbetween the two branches of the ANS, a shift in autonomic balance toward increasedparasympathetic activity, increased heart−brain synchronization, increased vascular resonance,and entrainment between diverse physiological oscillatory systems.Although the physiological phenomena associated with coherence can occur spontaneously,sustained episodes are generally rare. While specific rhythmic breathing methods may induceheart rhythm coherence and physiological entrainment for brief periods, cognitively directedpaced breathing is difficult for many people to maintain for more than about one minute(discussed in detail later). On the other hand, we have found that individuals can intentionallymaintain coherence for extended periods by self-generating, modulating, and sustaining a “heart-focused” positive emotional state. Using a positive emotion to drive the coherence mode appearsto excite the system at its resonant frequency, and coherence emerges naturally, making it easy tosustain for long periods.Self-regulation of emotional experience is a key requisite to the intentional generation ofsustained positive emotions—the driver of a shift to coherent patterns of physiological activity.Emotional self-regulation involves moment-to-moment management of distinct aspects ofemotional experience. One aspect involves the neutralization of inappropriate or dysfunctionalnegative emotions. The other requires that self-activated positive emotions are modulated toremain within the resonant frequency range of such emotions as appreciation, compassion, andlove, rather than escalating into feelings such as excitement, euphoria, and rapture, which areassociated with more unstable psychophysiological patterns.A series of tools and techniques, collectively known as the HeartMath System, provide asystematic process that enables people to self-regulate emotional experience and reliablygenerate the psychophysiological coherence mode (Childre & Martin, 1999; Childre & Rozman,2002, 2005). The primary focus of these techniques is on facilitating the intentional generation ofINTEGRAL REVIEWDecember 2009Vol. 5, No. 2a sustained, heart-focused positive emotional state. This is accomplished by a process thatcombines a shift in attentional focus to the area of the heart (where many people subjectivelyexperience positive emotions) which the self-induction of a positive feeling, such asappreciation. Our work has shown that this shift in focus and feeling experience allows thecoherence mode to emerge naturally and helps to reinforce the inherent associations betweencoherence and positive feelings. Our research also suggests that the intentional application ofthese coherence-building techniques, on a consistent basis, effectively facilitates a repatterningprocess whereby coherence becomes increasingly familiar to the brain and nervous system, andthus progressively becomes established in the neural architecture as new, stablepsychophysiological baseline or set point (McCraty, 2003; McCraty & Childre, 2004; McCraty& Tomasio, 2006). Once the coherence mode is established as the familiar pattern, the systemthen strives to maintain this mode automatically, thus rendering coherence a more readilyaccessible state during day-to-day activities, and even in the midst of stressful or challengingsituations.At the physiological level, the occurrence of such a repatterning process is supported byelectrophysiological evidence demonstrating a greater frequency of spontaneous (withoutconscious practice of the interventions) periods of heart rhythm coherence in individualspracticed in the HeartMath coherence-building techniques. Furthermore, a number of studiessuggest that this “repatterning” process can produce enduring system-wide benefits thatsignificantly impact overall quality of life (discussed below).While evidence clearly shows that the HeartMath positive emotion refocusing and emotionalrestructuring techniques lead to increased psychophysiological coherence, other approaches havealso been shown to be associated with increased coherence. For example, in a recent UCLAstudy, Buddhist monks meditating on generating compassionate love tended to exhibit increasedcoherence, and another study of Zen monks found that the more advanced monks tended to havecoherent heart rhythms, while the novices did not (Lehrer et al., 2003). This does not imply,however, that all meditation approaches lead to coherence; as we and others have observed,approaches that focus attention to the mind (concentrative mediation), and not on a positiveemotion, in general do not induce coherence.Benefits of Psychophysiological CoherenceIn terms of physiological functioning, coherence is a highly efficient mode that confers anumber of benefits to the system. These include: (1) resetting of baroreceptor sensitivity, whichis related to improved short-term blood pressure control and increased respiratory efficiency; (2)increased vagal afferent traffic, which is involved in the inhibition of pain signals andsympathetic outflow; (3) increased cardiac output in conjunction with increased efficiency influid exchange, filtration, and absorption between the capillaries and tissues; (4) increased abilityof the cardiovascular system to adapt to circulatory requirements; and (5) increased temporalsynchronization of cells throughout the body. This results in increased system-wide energyefficiency and metabolic energy savings (Lehrer et al., 2003; Langhorst, Schulz, & Lambertz,1984; Siegel et al., 1984).INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Psychologically, the coherence mode promotes a calm, emotionally balanced, yet alert andresponsive state that is conducive to cognitive and task performance, including problem-solving,decision-making, and activities requiring perceptual acuity, attentional focus, coordination, anddiscrimination. Individuals generally experience a sense of enhanced subjective well-beingduring coherence due to the reduction in extraneous inner “noise” generated by the mental andemotional processing of daily stress and the positive emotion-driven shift to increased harmonyin bodily processes. Many also report increased intuitive clarity and efficacy in addressingtroublesome issues in life.The use of coherence-building interventions has been documented in numerous studies to giverise to significant improvements in key markers of both physical and psychological health.Significant improvements in several objective health-related measures have been observed,including immune system function (McCraty et al., 1996; Rein et al., 1995), ANS function andbalance (McCraty et al., 1995; Tiller et al., 1996), and the DHEA/cortisol ratio (McCraty et al.,1998). At the emotional level, significant reductions in depression, anxiety, anger, hostility,burnout, and fatigue and increases in caring, contentment, gratitude, peacefulness, and vitalityhave been measured across diverse populations (Arguelles, McCraty, & Rees, 2003; Barrios-Choplin, McCraty, & Cryer, 1997; Luskin et al., 2002; McCraty et al., 1998; McCraty, Atkinson,Lipsenthal, et al. 2003; McCraty, Atkinson, & Tomasino, 2001, 2003). Other research hasdemonstrated significant reductions in key health risk factors (e.g., blood pressure, glucose,cholesterol) (McCraty, Atkinson, Lipsenthal, et al., 2003) and improvements in health status andquality of life in various populations using coherence-building approaches. More specifically,significant blood pressure reductions have been demonstrated in individuals with hypertension(McCraty, Atkinson, & Tomasino); improved functional capacity and reduced depression inpatients with congestive heart failure (Luskin et al.); improved glycemic regulation and qualityof life in patients with diabetes (McCraty, Atkinson, & Lipsenthal, 2000); and improvements inasthma (Lehrer, Smetankin, & Potapova, 2000). Coherence-building interventions have also beenfound to yield favorable outcomes in organizational, educational, and mental health settings(Arguelles et al., 2003; Barrios-Choplin et al.; Barrios-Choplin, McCraty, Sundram, & Atkinson,1999; McCraty et al., 2001; McCraty, Atkinson, Lipsenthal, et al.; McCraty, Atkinson,Tomasino, Goelitz, & Mayrovitz, 1999; McCraty & Childre, 2004; McCraty & Tomasio, 2004).In short, our findings on psychophysiological coherence essentially substantiate what humanbeings have known intuitively for thousands of years: namely, that positive emotions not onlyfeel better subjectively, but they also increase the synchronous and harmonious function of thebody’s systems. This optimizes our health, well-being, and vitality, and enables us to functionwith greater overall efficiency and effectiveness.A Typology of Psychophysiological InteractionIn the Appendix A we identify six distinct patterns of HRV, which appear to denote sixdifferent modes of psychophysiological interaction. Four of these modes are readily generated inthe context of everyday life. We have termed these Mental Focus, PsychophysiologicalIncoherence, Relaxation and Psychophysiological Coherence. Two further modes, EmotionalQuiescence and Extreme Negative Emotion, are generated under more extraordinary lifecircumstances. This appendix provides empirical data and detailed descriptions for each of these.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Looking more closely at our data, we found a number of empirical clues that point to a morefundamental conceptualization of the relationship between HRV patterns (which include bothheart rate and rhythm) and different emotional states. The first clue is that there is a generalrelationship between coherence and emotional valence, in that positive emotions are associatedwith physiological coherence and negative emotions with incoherence. The second clue is that,for certain emotions, we found a relationship between the morphology of the HRV waveformsand specific emotional states. The third finding of significance here is that we also foundevidence of HRV waveform patterns (namely, those characteristic of the Emotional Quiescenceand Extreme Negative Emotion modes) that appear to involve a rapid phase transition into aqualitatively different category of physiological function. In short, the empirical generalizationsuggested by these findings is that the morphology of HRV waveforms covaries with differentemotional experiences.Following the logic of this general relationship, we can thus use the six psychophysiologicalmodes to construct a typology—a conceptual “map”—showing the expected relationshipbetween different categories of subjective emotional experience and the different patterns ofphysiological activity associated with them (see Figure 4). This general theoretical schemeapplies to normal, healthy individuals experiencing emotions and feelings of relatively shortduration (minutes to hours).Figure 4. Graphic depiction of everyday states and hyper-states of psychophysiologicalinteraction distinguished by the typology. Two qualitatively different categories ofpsychophysiological interaction are depicted—the area within the inner circle represents theINTEGRAL REVIEWDecember 2009Vol. 5, No. 2range of emotional experience of “normal,” everyday life; the area beyond the outer circlerepresents psychophysiological hyper-states of extreme emotional experience. Thepsychophysiological transition from one region to another involves an abrupt phase transition,which is depicted graphically by the white space between the two circles. Two dimensionsdifferentiate the varieties of emotional experience shown; for simplification, the relevantpsychological and physiological variables are superimposed on the axis for each dimension. Onedimension is the degree of emotional arousal (vertical axis, high to low)—known to be covariantwith ANS balance. The second dimension is the valence of the emotion (horizontal axis, positiveor negative)—assumed covariant with the degree of activation of the hypothalamic-pituitary-adrenal (HPA) axis. Different patterns of HRV are predicted from the particular combination ofarousal and valence values on the two dimensions. Within the inner circle are six segments, eachof which demarcates a range of emotion experienced in everyday life. Typical HRV patternsassociated with each emotion are shown. The area beyond the outer circle depicts six hyper-states, in which intense emotional experience drives the activity of physiological systems pastnormal function into extreme modes. The known and predicted HRV waveform patternsassociated with these hyper-states are also shown. The labels “Depletion” and “Renewal,” on theleft and right-hand side of the diagram, respectively, highlight the relationship between thevalence of feelings and emotions experienced and the psychophysiological consequences for theindividual. Negative emotional states can lead to emotional exhaustion and depletion ofphysiological reserves. By contrast, positive emotional states are associated with increasedpsychophysiological efficiency and regeneration.Although the mapping is not isomorphic between data and concept, the typology provides acompelling and fruitful way of conceptualizing and organizing these phenomena. In addition tooffering some understanding of the relationships between different types of emotional experienceand their associated physiological processes, this scheme also aims to predict the distinguishingphysiological correlates of emotional states that, to our knowledge, have yet to be empiricallydescribed.The typology distinguishes between two general classes of psychophysiological interaction.One class reflects “normal” psychophysiological states associated with the variety of subjectiveexperiences of everyday life. This area is represented by the space within the inner circle shownin Figure 4. This area has been divided into six segments, each representing a different basicrange of emotion. The second class is a qualitatively different category of psychophysiologicalinteraction associated with extreme emotional experience, represented by the space beyond theouter perimeter of the circle in the figure. Because the patterns of psychophysiologicalinteraction in this space are predicted to show an abrupt movement—a phase shift—frompatterns associated with feelings typically experienced in everyday life to qualitatively distinctpsychophysiological patterns associated with the experience of extreme positive or extremenegative emotions, well beyond the range of normal feelings, we have labeled them as hyper-states. Evidence of such a phase shift can clearly be seen as an abrupt reduction in amplitude anda corresponding increase in frequency in the waveform patterns showing the movement fromPsychophysiological Coherence to the Emotional Quiescence, a positive hyper-state (Figure 9,Appendix A) and also in the movement from Psychophysiological Incoherence to ExtremeNegative Emotion, a negative hyper-state (Figure 10, Appendix A).INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Two dimensions common to the phenomenon of psychophysiological interaction provide thebasis for differentiating varieties of emotional experience in the typology. As evident in the term“psychophysiological,” there is a psychological element and a physiological element. 7 Forpurposes of simplification, we have superimposed the relevant psychological and physiologicalvariables on the axis representing each dimension in the figure.8 One dimension is the degree ofemotional arousal (high to low), which is known to be covariant with ANS balance. Thus, duringshort-term emotional experiences, the relative balance between the activity of the sympatheticand parasympathetic branches of the ANS is driven by the degree of emotional arousal.Accordingly, we have mapped emotional arousal and ANS balance together on the vertical axisin Figure 4.The second dimension is the valence (positive or negative) of the emotion, which isrepresented by the horizontal axis in Figure 4. Again for purposes of simplification, the valenceis assumed to be covariant with the degree of activation of the hypothalamic-pituitary-adrenal(HPA) axis, which controls the release of cortisol. For short-term emotional experiences, there isan increase in cortisol during negative emotional states and a decrease in cortisol release duringpositive emotional states.HRV patterns can be distinguished on the basis of amplitude, frequency, and degree ofcoherence. Empirical findings show that the two elements of the psychological dimension in ourscheme play a predominant role in determining the characteristics of the HRV pattern. Theamplitude of the HRV waveform is modulated by both the degree of emotional arousal (whichcorresponds to ANS activation) and emotional valence. In general, greater degrees of arousalwithin normal heart rate ranges produce waveforms of greater amplitude.9 However, as heart rateincreases, the amplitude of the HRV waveform decreases in linear relationship to heart rate untilit reaches a point beyond which the amplitude of the HRV waveform is compressed. This is dueto a biological constraint known as the cycle-length dependence effect. In terms of emotionalvalence, the amplitude of the HRV waveform increases during positive emotions, while itdecreases during negative emotions. The frequency of the HRV waveform is influenced by thepattern of ANS activation; increased parasympathetic activity leads to higher-frequency (faster)changes in the heart rhythm, while increased sympathetic activity is associated with lower-frequency, higher-amplitude (slower) changes. Finally, the degree of coherence of the HRVwaveform is largely determined by the emotional valence, with positive emotion increasingcoherence and negative emotion decreasing coherence. Different patterns of HRV can thereforeAlthough the psychological component involves at least three factors for a given emotionalexperience—emotional arousal, emotional valence, and the degree of cognitive engagement—we haveexcluded cognitive engagement to avoid the enormous complexity introduced when all three factors areconsidered simultaneously.8In reality the relationship is much more complicated. While there is a close intra-relationship betweeneach pair of variables on the axis, there are many life circumstances that give rise to a more complexinteraction between the emotional and physiological levels.9A secondary modulator of the HRV amplitude is the degree of cognitive engagement. High cognitiveengagement tends to reduce HRV, while low cognitive engagement increases HRV. As noted, forpurposes of simplification this factor is not considered in this model.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2be predicted from the conjunction of the particular combination of arousal and valence values onthe two dimensions in our typology.Following this logic, therefore, each of the six segments within the inner circle in Figure 4demarcates a range of emotion and its corresponding representative HRV waveform patterns forthe variety of emotional experiences that typify everyday life. Organized in terms of degree ofarousal and valence, and rotating clockwise around the figure, these are the familiar emotions weexperience from day to day. They are labeled: Happiness–Excitement, Love–Appreciation,Contentment–Serenity, Sadness–Apathy, Frustration–Resentment, and Anger–Anxiety. At thecenter of the circle, in a small area surrounding the intersection of the two axes, is the space ofEmotional Impassivity (not labeled in Figure 4). Involving little or no emotional feeling, eitherpositive or negative, emotional impassivity is typically experienced when the individual ismentally engaged in performing a familiar action or routine task. These seven areas within thecircle of day-to-day emotional life denote substantively different emotions and feelingssubjectively experienced by the individual.Psychophysiological Hyper-StatesQualitatively distinct from the feelings of daily life are six distinct psychophysiological hyper-states reflecting the body’s response to extreme emotions. Because these hyper-states involve aphase shift in physiological organization and psychological experience that is discontinuous fromthe states of normal, everyday emotional life, they are set apart beyond the perimeter of the outercircle in Figure 4.Generally speaking, the psychophysiological hyper-states are indicative of two quite differentdirections of movement in bodily processes. As described below, hyper-states involving extremepositive emotions are transcendent states in which the individual’s emotional experienceinvolves the feeling of spiritual connectedness to something larger and more enduring beyondthemselves. Typically these states are associated with selfless actions and are also generative ofbodily renewal. By contrast, hyper-states of extreme negative emotions are all-consuming statesof self-absorption and self-focus. These states are usually associated with highly destructivebehavior—either directed at the self and/or projected out onto others—and have detrimental,even devastating, consequences. Negative hyper-states lead to a depletion of the body’s energyand resources which, in the long term, results in the degeneration of bodily function.Shown beyond the high end of the arousal axis are two states of hyper-arousal characterizedby extreme emotional activation. The extreme emotional activation can result in a loss of self-control, which may lead to unpredictable behavior. It is important to understand that theseextreme emotions are associated with the highest level of physiological activation. This drivesthe heart rate past physiological norms to such a degree that the amplitude of the HRV waveformbecomes extremely low.On the negative side, violent, uncontrollable anger and rage, or overwhelming fear andanxiety are the hyper-aroused emotions experienced here. As already mentioned, we haveempirical data documenting the HRV pattern associated with this state (see the waveform patternshowing the movement to “intense anger” in Figure 10, Appendix A). On the positive side,INTEGRAL REVIEWDecember 2009Vol. 5, No. 2uninhibited rejoicing and jubilation, or overpowering exaltation and ecstasy are predicted, in theabsence of any empirical data documenting this hyper-state. We believe it is thispsychophysiological state that is accessed during collective rituals that lead to trance states andspiritual rapture. It also may be possible to enter this state from hyper-aroused, uncontrolledpositive emotions that induce a positive hysteria, such as can result from an unexpected,overwhelmingly positive event—for example, reuniting with a loved one who was in a life-threatening situation.At the low end of the arousal axis are two states of hypo-arousal, the complement to the twostates of hyper-arousal we have just described. On the positive side, the individual experiencesan ego-less feeling of profound inner peace and deep spiritual connectedness. Typically, thisstate is accessed by self-disciplined meditative and spiritual practice. Physiologically, theemotional experience of this state of extremely low arousal is characterized by HRV waveformpatterns of very low amplitude with some degree of coherence, reflecting the body’s state ofcomplete calm and rest.On the negative side, individuals can enter a state of hypo-arousal when they have been in anenduring negative emotional state (weeks to months). This is a state of self-engrossing desolationand despair and is accompanied by obsessive negative mental and emotional activity, such asthat experienced in prolonged grief or long-term depression. However, an episode of severetrauma or negative emotion can rapidly propel an individual into this state. Either way, this canresult in a depletion of physiological reserves, which is in turn reflected in a very low-amplitudeHRV waveform. Often, individuals in this hypo-state are emotionally numb and sociallyalienated or withdrawn.If this state is sustained on a long-term basis, there is further depletion of both the sympatheticand parasympathetic systems. In the first stages of this process, sympathetic activity becomessubstantially reduced, resulting in an autonomic imbalance. As the process continues,parasympathetic activity (vagal tone) is correspondingly reduced. The process culminates with aphase-transition into exhaustion and breakdown.Between the four states of extreme hyper-arousal and extreme hypo-arousal in the mid-rangeof emotional arousal, are two other states of extraordinary emotional experience. On the positiveside, there is the state of wholly self-less spiritual love in which the individual experiences adeep feeling of all-embracing “big love”—Agape, as defined by the dictionary: a love that isopen to and non-judgmental about all perceptions, cognitions, and intuitions. To enter this hyper-state requires a deep, heart-focused, self-less love, which can be associated with contemplativeintrospection. This hyper-state is accessed via a phase transition when this deep heart-focusedintrospection is sustained for a few minutes or more. This state is experienced as a substantialreduction in mental and emotional “chatter” to a point of internal quietness, often associated witha profound feeling of peace and serenity. This is the phase space within which the EmotionalQuiescence mode falls. We also expect this hyper-state to be associated with other types ofemotional experience that may have a spiritual dimension, such as those accessed by a number ofintrospective disciplines and practices.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Physiologically, there are two likely mechanisms to explain how this hyper-state occurs. Oneis that, in this state, the sympathetic and parasympathetic outflow from the brain to the heart issubstantially reduced—reduced to such a degree that the amplitude of HRV waveform becomesvery low. The other logical possibility is that the heart acts as an antenna to a field of informationbeyond space and time surrounding the body that directly informs the heart and modulates itsrhythmic patterns. As astounding as this may sound, there is compelling evidence from our studyof the electrophysiology of intuition that points in this direction (McCraty, Atkinson, & Bradley,2004a, 2004b).On the negative side, there is a hyper-state in which the individual is consumed by powerfulmalevolent feelings of extreme ill-will and hatred. These ego-centric feelings occupy virtually allof the individual’s time and energy and engage one’s whole attention. Typically, these feelingsof evil and harm are not directed inwards against the self, but, instead, are projected outwards tobe expressed as an intense pathological desire to cause great pain and suffering to others.Sustained, fanatical feelings of ill-will toward others can propel an individual into this hyper-state. Subjectively, there is a substantial reduction in mental and emotional “chatter” and acorrespondingly heightened state of calm, malevolent feelings. The emotional calm reflects theindividual’s disassociation from the humanity of others and the total acceptance of the all-consuming negative thoughts and emotions experienced in this state. We expect this hyper-stateto be one that can be entered by individuals who hold fanatical beliefs based on extreme negativestereotypes or caricatures of others. This is often the case with radical groups on the margins ofsociety who see themselves suffering a great injustice or harm from the hands of those they hate.Physiologically, this hyper-state likely involves a zombie-like state in which there is suchemotional disassociation that the amplitude of HRV waveform becomes very low but with somevariability spikes which may reflect the individual’s momentary transitions between differentemotions.To conclude, the typology provides a more general conceptual framework from which to viewthe six modes of psychophysiological interaction we identified in our empirical studies. We havefound the typology a useful way of conceptually organizing the broad range and highly variablephenomena in this domain. It will be up to future research to test the degree to which thetypology offers a fruitful map of the nature and organization of the different types of emotional–physiological interaction.Heart Coherence and Psychophysiological FunctionSo far, we have discussed how changes in the patterns of neural activity can encode andtransmit information in the psychophysiological networks independent of changes in the amountof activity and how this level of information processing may well play a more fundamental rolein information exchange than changes in the amount and/or intensity of neural activity. In thissection we will see that increased coherence is associated with favorable changes in variousaspects of physiological function, which in turn are associated with psychological benefits. Weintroduce this discussion by describing how the amount of information traveling through theafferent nerves increases during coherence, and we then examine the role that cardiac afferentINTEGRAL REVIEWDecember 2009Vol. 5, No. 2input plays in the neural pathways involved in pain perception, respiratory function, emotionalprocessing, and cognitive performance.The vagus nerve is a major conduit though which afferent neurological signals from the heartand other visceral organs are relayed to the brain. Psychophysiologist Paul Lehrer has shown thatby using heart rhythm feedback to facilitate a state of physiological coherence (which he calls“resonance”), a lasting increase in baroreflex gain10 is accomplished independent of respiratoryand cardiovascular changes, thus demonstrating neuroplasticity of the baroreflex system (Lehreret al., 2003). This shift in baroreflex gain indicates that with repeated episodes of coherence, theactivation threshold of some of the mechanosensory neurons in the baroreflex system is resetand, as a result, these neurons increase their output accordingly.In addition, a basic property of mechanosensory neurons is that they generally increase theiroutput in response to an increase in the rate of change in the function they are tuned to (heartrate, blood pressure, etc.). During heart rhythm coherence, there is an increase in beat-to-beatvariability in both heart rate and blood pressure, which is equivalent to an increase in the rate ofchange. This results in an increase in the vagal afferent traffic sent from the heart andcardiovascular system to the brain. With regular practice in maintaining the coherence mode, it islikely that increased vagal afferent traffic would also be observed even when one is not in thismode. This is due to the fact that the mechanosensory neurons’ threshold is reset as a result ofthe coherence-building practice, thus establishing a new baseline level of afferent traffic.Generating an increase in vagal afferent traffic through noninvasive approaches such as heart-based emotion refocusing techniques and heart rhythm coherence feedback has a number ofpotential benefits. In recent years, a number of clinical applications for increasing vagal afferenttraffic have been found; however, the increase in afferent activity is usually generated byimplanted or external devices that stimulate the vagal afferent pathways, typically in the leftvagus nerve. Vagal stimulation is an FDA-approved treatment for epilepsy and is currently underinvestigation as a therapy for obesity, depression, anxiety, and Alzheimer’s disease (Groves &Brown, 2005; Kosel & Schlaepfer, 2003). It has been established that an increase in the normalintrinsic levels of vagal afferent traffic inhibits the pain pathways traveling from the body to thethalamus at the level of the spinal cord (discussed below) and a recent study has found thatstimulation of the afferent vagal pathways significantly reduces cluster and migraine headaches(Mauskop, 2005). Vagal nerve stimulation has also been shown to improve cognitive processingand memory (Hassert, Miyashita, & Williams, 2004)—findings that are consistent with those ofseveral recent studies of individuals using heart rhythm coherence-building techniques(discussed later in this article).Baroreflexes are homeostatic reflexes that regulate blood pressure. Through them, increases in bloodpressure produce decreases in heart rate and vasodilation, while decreases in blood pressure produce theopposite. Baroreflex gain is commonly calculated as the beat-to-beat change in heart rate per unit ofchange in blood pressure. Decreased baroreflex gain is related to impaired regulatory capacity and aging.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Afferent signals from the heart modulate the neural pathways involved in the perception ofpain. Numerous reports from individuals using the HeartMath coherence-building techniquesindicate that they are able to greatly reduce their experience of bodily pain, often to a pointwhere they can reduce or eliminate pain medications. This is true of both visceral and cutaneouspain. The HeartMath system is currently employed by numerous clinicians as a pain managementaid, and has proven effective in patients with a wide range of conditions, including chronic jointpain, serious burns, and traumatic brain injury. The generation of increased vagal afferentactivity during the coherence mode provides a likely mechanism to account for the reduction ofpain associated with increased heart rhythm coherence.Several mechanisms have been identified that explain how increased vagal afferent activitydecreases pain sensitivity and increases pain threshold. Nociceptive information (pain signals)from the skin and internal organs is carried to cell bodies located in the dorsal root ganglia of thespinal cord. Axons from neurons in the dorsal root ganglia penetrate the spinal cord and conveyafferent pain information to localized regions of the gray matter in the cord. From there, afferentinformation ascends in pathways to both the lateral and medial thalamus. Cells of the lateralthalamus in turn project to the primary somatosensory cortex, where the location, intensity, andduration of the painful stimulus are analyzed. Information is sent from the medial thalamus to theinsular cortex, amygdala, and cingulate gyrus, where motivational-affective components of pain,including autonomic adjustments, occur. This pathway is called the spinothalamic tract (STT)and, although not the only pain pathway, it is the main and most studied system that transmitsvisceral sympathetic afferent pain information to the brain (Foreman, 1989).Afferent fibers in the vagus nerve participate in the modulation of pain partly by modulatingthe flow of pain signals in the STT. An increase in afferent vagal activity causes a generalinhibitory effect at most levels of the spinal cord on neurons that transmit nociceptiveinformation to the thalamus and then to areas of the brain involved in pain perception. Vagalafferent fibers terminate primarily in the caudal medulla of the brain stem and nucleus tractussolitarius (NTS), and evidence shows that suppression of spinal neuronal activity is dependentupon the NTS connections. It has been demonstrated that the cardiac branch of the vagus nervemakes up the major contribution for the inhibitory responses on the spinal pain signals and thatleft vagal stimulation suppresses approximately 60% of the STT cells. Thus, the predominanteffect of increased vagal afferent activity, which is associated with increased coherence, is thesuppression of somatic and visceral input to STT cells, which provides a mechanism fordecreasing pain (Foreman, 1994, 1997).It is well known that the respiratory rhythm modulates the pattern of the heart rhythm. Thisbreath-related modulation of the heart rhythm is called respiratory sinus arrhythmia (RSA)(Hirsh & Bishop, 1981). RSA reflects the complex interaction of central respiratory drive,autonomic afferent signals, efferent outflow from the brain stem, and respiratory mechanicsINTEGRAL REVIEWDecember 2009Vol. 5, No. 2within the thorax. The phenomenon is dependent on the frequency and amplitude of respirationas well as on the underlying autonomic state of the organism.11Since we have conscious control over our breathing, cognitively-directed breathing exercisescan be used to impose a breathing rhythm on the heart rhythms. Thus, when we breathe at a slow,rhythmic rate (five seconds in and then five seconds out), we can facilitate coherence andentrainment. However, we do not normally think about our breathing. It is automatic; ourbreathing depth and rate varies without our conscious awareness due to changes in the inputs tothe respiratory centers in the brain stem that control respiration.Among these inputs is the afferent neurological information from the heart and cardiovascularsystem. Our breathing rate is affected by and often synchronized to the cardiac cycle, whichmeans that changes in our heart rate and rhythm can affect our breathing rate and patterns.12During sleep or rest, coupling between the cardiac cycle and respiration is the strongest, and attimes of stress, coupling between the heart and respiration becomes disrupted (Langhorst,Schulz, & Lambertz, 1986; Raschke, 1986a, 1986b; Turpin, 1986).It is well established that changes in emotional states also alter breathing rates. Agitated statessuch as anger and frustration increase the breathing rate and reduce tidal volume (the depth of thebreath), while positive emotional states slow the breathing rate and increase tidal volume. Theseemotion-related changes in breathing are likely to result, at least in part, from changes in inputfrom the cardiovascular centers.Because respiration modulates the heart rhythm, it can be intentionally used as a powerfulintervention that can have quick and profound body-wide effects. As we have conscious controlover our breathing rate and depth, we can consciously modulate the heart rhythm and thuschange the afferent neural patterns sent to the brain centers that regulate autonomic outflow,emotion, and cognitive processes. Our experience with breathing exercises is that they areeffective primarily due to the fact that they modulate the heart’s rhythmic patterns.However, it is important to emphasize that coherence is associated with positive emotionsindependent of conscious alterations in one’s breathing rhythm. In our earlier studies, whichwere focused on the physiological correlates of different emotional states, instructions to subjectspurposely made no mention of altering breathing rates or depths. We found that when sustainedpositive emotional states were maintained, increased heart rhythm coherence and entrainmentThe effects of lung inflation are mediated by sensory neurons in the lungs that respond to stretch. Theseneurons increase their firing rate as the lungs expand upon inspiration. The output from these neuronstravels to the brain stem and inhibits the parasympathetic outflow from the brain to the heart, resulting inan increase in heart rate. During expiration, the stretch is reduced and the inhibition is removed. The heartrate is quickly reduced. This interaction between the lungs and brain stem is only one source of RSA;however, it provides an easy way to conceptualize RSA.12The influence of afferent information from the heart on respiration was studied in great detail in the1940s and 1950s. The cardiovascular afferent systems excite the respiratory centers, and if this input isinhibited, so is respiration. For a review of this earlier research, see Chernigovskiy (1967).INTEGRAL REVIEWDecember 2009Vol. 5, No. 2between the heart rhythm, blood pressure rhythms, and respiratory rhythms emerged independentof any conscious alterations in breathing pattern (McCraty et al., 1995; Tiller et al., 1996).Although breathing techniques may sometimes facilitate a feeling shift, coherence that isdriven through the use of such techniques alone does not necessarily shift one’s emotional state.For example, it is possible to breathe at a rate of six breaths per minute (a 10-second rhythm) andstill be feeling anxiety or other feelings of unease. In addition, many people find it difficult toconsciously maintain breathing rates at a 10-second rhythm for more than about a minute. On theother hand, by focusing attention on self-generating a positive emotion while pretending to“breathe” this feeling through the area of the heart in a relaxed manner, smooth, coherent heartrhythm patterns occur naturally and are easier to sustain for longer periods of time. This has theadded benefit of not only establishing coherence as the familiar pattern, but also strengtheningthe connection between the constituent physiological patterns of coherence—of which heartrhythm is key—and the positive feeling state.Afferent input from the heart, and, in particular, the pattern of the heart’s rhythm, also plays akey role in emotional experience. As described previously, our research suggested a fundamentallink between emotions and changes in the patterns of both efferent and afferent autonomicactivity, as well as changes in ANS activation, which are clearly reflected in changes in the heartrhythm patterns. The experience of negative emotions is reflected in more erratic or disorderedheart rhythms, indicating less synchronization in both the activity of brain structures that regulateparasympathetic outflow and in the reciprocal action between the parasympathetic andsympathetic branches of the ANS. In contrast, sustained positive emotions are associated with ahighly ordered or coherent pattern in the heart rhythms, reflecting greater overallsynchronization in these same systems.It is important to emphasize, however, that the heart’s rhythmic beating patterns not onlyreflect the individual’s emotional state, but they also play a direct role in determining emotionalexperience. At the physiological level, as shown in Figure 5, afferent input from the heart isconveyed to a number of subcortical regions of the brain that are involved in emotionalprocessing, including the thalamus, hypothalamus, and amygdala. Moreover, cardiac afferentinput has a significant influence on the activity of these brain centers (Adair & Manning, 1975;Cameron, 2002; Foreman, 1997; Frysinger & Harper, 1990; Oppenheimer & Hopkins, 1994;Zhang, Harper, & Frysinger, 1986). For example, activity in the amygdala has been found to besynchronized to the cardiac cycle (Frysinger & Harper, 1990; Zhang et al.). Theseunderstandings support the proposition that afferent information from the heart is directlyinvolved in emotional processing and emotional experience.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Afferent PathwaysCerebral Cortex• Body perception• Pain perception• Arousal (sleep/waking)• Hunger perceptionHypothalamusThalamusPeriaqueductalGray(PAG)ParabrachialComplexVisual andAuditory Input• Fear/Anxiety• Analgesia• Autonomic modulation• Fight-or-flight• Affective defenseDorsal Vagal ComplexNucleus of TractusSolitarius (NTS)• Receives afferent input from heart,lungs, baroreceptor nerves,chemoreceptors, upper respiratory andalimentary tracts, and faceVagusNerveFacialInputTasteInputAreaPostrema• Monitors blood• Food poisoning• Motion sickness• Emesis (vomiting)Figure 5. Diagram of the currently known afferent pathways by which information fromthe heart and cardiovascular system modulates brain activity. Note the direct connectionsfrom the NTS to the amygdala, hypothalamus, and thalamus. Although not shown, there is alsoevidence emerging of a pathway from the dorsal vagal complex that travels directly to the frontalcortex.These findings and those from our own research led us to ponder the fundamentalphysiological significance of the covariance between the heart’s rhythms and changes inemotion. This question was especially intriguing in light of current views in neuroscience thatthe contents of feelings are essentially the configurations of body states represented insomatosensory maps (Cameron, 2002; Damasio, 2003). This was of course the essence of thetheory of emotion first proposed by William James (1884), which has been refined by manyresearchers over the years.A useful way of understanding how the heart is involved in the processing of emotionalexperience is to draw on Pribram’s theory of emotion (Pribram & Melges, 1969). In this theory,the brain is viewed as a complex pattern identification and matching system. Pribram’s basicconcept is that of a “mismatch” between familiar input patterns and current input patterns thatare different or novel. It is this mismatch that provides the mechanism by which feelings andemotions are generated.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2According to Pribram’s model, past experience builds within us a set of familiar patterns,which are instantiated in the neural architecture. Inputs to the brain from both the external andinternal environments contribute to the maintenance of these patterns. Within the body, manyprocesses provide constant rhythmic inputs with which the brain becomes familiar. Theseinclude the heart’s rhythmic activity; digestive, respiratory and hormonal rhythms; and patternsof muscular tension, particularly facial expressions. These inputs are continuously monitored bythe brain and help organize perception, feelings and behavior.Familiar input patterns form a stable backdrop, or reference pattern, against which newinformation or experiences are compared. When an input pattern is sufficiently different from thefamiliar reference pattern, a “mismatch” occurs. This mismatch, or departure from the familiarpattern, is what underlies the generation of feelings and emotions. In physiological terms,Pribram suggests that the low-frequency oscillations generated by the heart and bodily systemsare the carriers of emotional information, and that the higher frequency oscillations found in theEEG reflect the integration, perception, and labeling of these body states along with perceptionof sensory input from the external environment. The mismatch between a familiar pattern and apattern that is new or novel in either of these informational inputs is what activates emotionalchanges (McCraty, 2003; McCraty & Tomasio, 2006).Although inputs originating from many different bodily organs and systems are involved inthe processes that ultimately determine emotional experience, it is now abundantly clear that theheart plays a particularly important role. The heart is the primary and most consistent source ofdynamic rhythmic patterns in the body. Furthermore, the afferent networks connecting the heartand cardiovascular system with the brain are far more extensive than the afferent systemsassociated with other major organs (Cameron, 2002). Additionally, the heart is particularlysensitive and responsive to changes in a number of other psychophysiological systems. Forexample, heart rhythm patterns are continually and rapidly modulated by changes in the activityof either branch of the ANS, and the heart’s extensive intrinsic network of sensory neurons alsoenables it to detect and respond to variations in hormonal rhythms and patterns (Armour, 1994).In addition to functioning as a sophisticated information processing and encoding center,(Armour & Kember, 2004) the heart is also an endocrine gland that produces and secreteshormones and neurotransmitters (Cantin & Genest, 1985, 1986; Gutkowska, Jankowski,Mukaddam-Daher, & McCann, 2000; Huang et al., 1996; Mukoyama et al., 1991). As we willsee later, with each beat, the heart not only pumps blood, but also continually transmits dynamicpatterns of neurological, hormonal, pressure, and electromagnetic information to the brain andthroughout the body. Therefore, the multiple inputs from the heart and cardiovascular system tothe brain are a major contributor in establishing the dynamics of the familiar baseline pattern orset point against which the current input of “now” is compared.A striking example illustrates the extensiveness of the influence of cardiac afferent input onemotional experience as well as the operation of the mismatch mechanism. Research shows thatpsychological aspects of panic disorder are actually frequently created by an unrecognizedcardiac arrhythmia. One study found that DSM-IV criteria for panic disorder were fulfilled inmore than two-thirds of patients with sudden-onset arrhythmias. In the majority of cases, oncethe arrhythmia was discovered and treated, the symptoms of panic disorder disappeared(Lessmeier et al., 1997). When the heart rate variability patterns of such an arrhythmia areINTEGRAL REVIEWDecember 2009Vol. 5, No. 2plotted, the erratic, incoherent waveform appears quite similar to the heart rhythm patternproduced during strong feelings of anxiety in a healthy person. Because the sudden, large changein the pattern of afferent information is detected by the brain as a mismatch relative to the stablebaseline pattern to which the individual has adapted, it consequently results in feelings of anxietyand panic.The above example illustrates the immediate and profound impact that changes in the heart’srhythmic activity can have on one’s emotional experience. In this example—as is usually thecase—such changes occur unconsciously. One of the most important findings of our research,however, is that changes in the heart’s rhythmic patterns can also be intentionally generated.This shift in the heart’s rhythmic patterns is one of the physiological correlates of using theHeartMath positive emotion-based coherence-building techniques, which couple an intentionalshift in attention to the physical area of the heart with the self-induction of a positive emotionalstate. We have found that this process rapidly initiates a distinct shift to increased coherence inthe heart’s rhythms. This, in turn, results in a change in the pattern of afferent cardiac signalssent to the brain, which serves to reinforce the self-generated positive emotional shift, making iteasier to sustain. Through the consistent use of the coherence-building techniques, the couplingbetween the psychophysiological coherence mode and positive emotion is further reinforced.This subsequently strengthens the ability of a positive feeling shift to initiate a beneficialphysiological shift towards increased coherence, or a physiological shift to facilitate theexperience of a positive emotion.While the process of activating the psychophysiological coherence mode clearly leads toimmediate benefits by helping to transform stress in the moment it is experienced, it can alsocontribute to long-term improvements in emotion regulation abilities and emotional well-beingthat ultimately affect many aspects of one’s life. This is because each time individualsintentionally self-generate a state of psychophysiological coherence, the “new” coherentpatterns—and “new” repertoires for responding to challenge—are reinforced in the neuralarchitecture. With consistency of practice, these patterns become increasingly familiar to thebrain. Thus, through a feed-forward process, these new, healthy patterns become established as anew baseline or reference, which the system then strives to maintain. It is in this way thatHeartMath tools facilitate a repatterning process, whereby the maladaptive patterns that underliethe experience of stress are progressively replaced by healthier physiological, emotional,cognitive, and behavioral patterns as the “automatic” or familiar way of being (McCraty &Tomasio, 2006).Coherence and Cognitive PerformanceIt is now generally accepted that the afferent neurological signals the heart sends to the brainhave a regulatory influence on many of the ANS signals that flow from the brain to the heart, tothe blood vessels, and to other glands and organs. However, it is less commonly appreciated thatthese same cardiovascular afferent signals involved in physiological regulation also cascade upinto the higher centers of the brain and influence their activity and function. Of particularsignificance is the influence of the heart’s input on the activity of the cortex—that part of thebrain that governs thinking and reasoning capacities. As we will see, depending on the nature ofthe heart’s input, it can either inhibit or facilitate working memory and attention, corticalINTEGRAL REVIEWDecember 2009Vol. 5, No. 2processes, cognitive functions, and performance (Hansen, Johnsen, & Thayer, 2003; Lacey &Lacey, 1974; Rau, Pauli, Brody, Elbert, & Birbaumer, 1993; Sandman, Walker, & Berka, 1982;van der Molen, Somsen, & Orlebeke, 1985).Our research on psychophysiological coherence has provided new insight into the relationshipbetween heart activity and cognitive performance. The context for this is described in detail inAppendix B. It describes how psychophysiologists John and Beatrice Lacey’s baroreceptorhypothesis identified a relationship between the heart’s activity and cognitive performance. Thiswork was furthered by Christoph Wölk and Manfred Velden in Germany, who identified theimportance of heart rate’s pattern and stability in influencing neurological functioning. Althoughwe agree with Wölk and Velden’s conclusions, the primary focus of previous work in this areahas been on micro-scale temporal patterns of cardiac activity, occurring within a single cardiaccycle, or, at most, across 3–4 heartbeats. However, the interactions between the heart and brainare much more complex and also occur over longer time periods (sequences of heartbeatsoccurring over seconds to minutes). Based on the evidence we report below, we believe thatpatterns of the heart’s rhythmic activity over a longer time scale are also involved in influencingcognitive performance. Moreover, it appears that these macro-scale temporal patterns ofcardiovascular afferent activity can have a much greater effect on performance than micro-scalepatterns. Therefore, a broader hypothesis is called for.The Heart Rhythm Coherence Hypothesis: A Macro-Scale PerspectiveIn the course of conducting our studies, we had received numerous reports from individualsable to maintain the psychophysiological coherence mode that their performance in variousactivities had noticeably improved. These involved faculties and abilities requiring theprocessing of external sensory information (e.g., speed and accuracy, coordination, andsynchronization, such as in sports and the performing arts) as well as processes requiringprimarily internal focus (e.g., problem solving, decision making, creativity, and intuition, such asin business and intellectual activities). This led us to postulate that psychophysiologicalcoherence and the associated macro-scale patterns of the temporal organization of the heart’srhythmic activity—heart rhythm patterns occurring over seconds to minutes—also have animportant effect on cognitive processes and intentional behavior. Focusing on the nature of theorganization of the heart’s rhythmic activity, which reflects emotional state, we hypothesize thatemotion-driven changes in global psychophysiological function, and the resulting change in thepattern of heart rhythm activity, are also directly related to the facilitation or inhibition of thebrain processes involved in cognitive function. In specific terms, sustained positive emotionsinduce psychophysiological coherence, which, in turn, is reflected in increased heart rhythmcoherence. Thus, the greater the degree of emotional stability and system-wide coherence, thegreater the facilitation of cognitive and task performance. We call this hypothesis the heartrhythm coherence hypothesis.A number of research projects have been carried out to test this hypothesis. Appendix Cdescribes three studies that show evidence supporting the hypothesis. The first showed thatmacro-scale patterns of cardiac activity can produce a larger effect on the inhibition/facilitationof cognitive performance than the much smaller inhibition/facilitation fluctuations inperformance observed by Wölk and Velden. It found an approximately six times greaterINTEGRAL REVIEWDecember 2009Vol. 5, No. 2improvement in performance than previous studies involving similar methods. The second wasan independent study conducted in the UK by Dr. Keith Wesnes, who concluded that learningand practicing the HeartMath positive emotion-focused coherence-building techniques appears toenhance an individual’s memory capacity and also improves self-reported calmness. The thirdstudy was funded by the U.S. Department of Education and carried out with the cooperation ofthe Claremont Graduate University’s School of Educational Studies involving tenth gradestudents in two large California high schools. It found significant reduction in test anxiety as wellas higher test scores for students who learned the positive emotion-focused coherence-buildingtechniques in the TestEdge program.Overall, the evidence provided by the three studies described in Appendix C indicates that aspecific macro-scale pattern of cardiac activity—heart rhythm coherence—is associated withsignificant improvement in cognitive performance. Not only is this outcome observed in a simplereaction time experiment, but the data suggest that this facilitative effect also extends acrossmore complex domains of cognitive function, including memory and even academic testperformance. It also appears that the influence of the coherence mode on cognitive performanceis substantially larger in magnitude than that previously documented for changes in cardiacactivity patterns on a micro scale.Assuming these results are validated by other researchers, it is worth considering the likelypathways and mechanisms that could explain these findings. This entails developing anexplanation that complements the micro-pattern hypotheses of the Laceys and Wölk and Velden,by identifying other physiological mechanisms that may account for these results. The micro-pattern hypothesis presents a somewhat simplified view of heart–brain interactions, which is notadequate to describe the full range of information communication that takes place between theheart and brain: it only addresses the smaller fluctuations in performance that are associated withphysiological changes occurring within a single cardiac cycle or across several heartbeats. As wehave seen, however, there are macro-scale temporal patterns that have a significant carry-overeffect on cognitive performance. To build an adequate understanding of the physiologicalmechanisms involved requires developing a deeper understanding of the complexity of heart–brain interactions. This is reflected in the discussion below in three primary ways: first, that theinfluence of cardiovascular afferent input on the brain is more elaborate than that considered inthe micro-pattern hypothesis; second, that afferent input from the heart has effects on braincenters other than the thalamus; and third, that the alpha rhythm is not the only brain rhythmsynchronized to the heart.A More Complex PictureComplexity of Cardiac Afferent SignalsOne of the underlying assumptions of the micro-pattern hypothesis is that there is a one-to-one correspondence between each heartbeat and the burst of neural activity sent to the brain fromthe cardiac mechanosensory neurites. However, at the level of the macro-scale heart−braininteractions investigated here, the dynamics of the generation and transmission of cardiovascularafferent input involve many types of neurons and a multiplicity of pathways operating overdifferent time scales.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2There are approximately 40,000 sensory neurites in the human heart involved in relayingafferent information to the brain. Of these, just 20% are mechanosensory neurons. Of this 20%,only a small proportion actually fire in unison with each heartbeat. Moreover, there are at leastfive different types of mechanosensory neurons. Almost all mechanosensory neurons aresensitive to rate of change, in that their activity levels increase in a nonlinear manner in responseto change in the system. Some increase their firing rate only when blood pressure decreases,while others increase only during pressure increases. Still others are only sensitive to largemovements in the rate of change of heart rate or blood pressure (Armour & Kember, 2004).Thus, there is only a minority of sensory neurites whose output activity exhibits a one-to-onerelationship to the heartbeat and regional changes in ventricular blood pressure.To add to the complexity, the heart’s intrinsic nervous system has both short-term and long-term memory that affects cardiac function (and thus afferent signals) over two different timescales: (1) variations in activity patterns that occur in response to rapidly occurring alterations inlocal mechanical status over milliseconds; and (2) variations in activity patterns of a globalnature that operate over time scales of seconds to minutes (Armour, 2003; Armour & Kember,2004). Thus, in addition to the information related to a single cardiac cycle, there is alsorhythmic information occurring over longer time scales that may modulate brain activity. Thefact that many of the neurons respond primarily to rate of change, and that changes in activitypatterns can last for minutes, are important factors in understanding how heart–brain interactionsare affected during coherence and can have an extended carry-over effect. This is because in thecoherence mode there is an increased rate of change in beat-to-beat variability of both heart rateand blood pressure, in addition to the increased order in the temporal patterns of activity of thecardiovascular system. While it is likely, under normal pressure variations and heart rates, thatthe overall amount of afferent neural activity reaching the brain is the same or nearly the samefrom one heartbeat to the next, it is our contention that the macro-scale patterns of neuralactivity can be quite different.In this regard, Wölk and Velden made an important observation in noting that the frequencyand stability of the afferent input were important factors affecting sensory-motor performance(Wölk and Velden, 1989). In this context, however, we suggest that the concept of activitypattern is more appropriate than the concept of frequency. This is because it is in the interspikeinterval (the temporal space between consecutive spikes of the neural activity) that information isencoded. Thus, it is the overall pattern of activity and not merely its frequency that contains themeaning of the information enfolded in the signals. Furthermore, we consider the stability of thepattern over longer time scales, those of seconds to minutes. Therefore, to understand the effectsof cardiovascular afferent signals on the brain, the heart’s rhythmic pattern over longer timescales must also be considered as an important factor in itself, in addition to those of stimulusintensity, heart rate, and pressure. As we have seen, it is likely that the macro-scale pattern of theheart’s activity may have a much greater effect on performance than the within-cardiac cycleeffects.Afferent Input to Brain Centers other than the ThalamusAnother important consideration, in relation to heart–brain interactions, is that while themicro-pattern model focuses solely on cardiovascular input to the thalamus, there are otherINTEGRAL REVIEWDecember 2009Vol. 5, No. 2neural pathways by which the heart’s input can modulate cortical activity and thus performance.As shown in Figure 5, cardiovascular inputs from the vagal afferent nerves first reach the nucleusof tractus solitarius (NTS) and from there travel directly to the parabrachial complex,periacqueductal grey, thalamus, hypothalamus, and amygdala. There are then connections bywhich the afferent inputs move from the amygdala, hypothalamus, and thalamus to the cerebralcortex. There is also evidence to suggest the existence of afferent pathways from the medulladirectly to the prefrontal cortex (McCraty et al., 2004b).Although this diagram primarily shows the afferent pathways—one-way flow of input to thebrain—in most cases the regions are reciprocally interconnected such that information flows inboth directions. This reciprocally interconnected network allows for continuous positive andnegative feedback interactions and the integration of autonomic responses with the processing ofperceptual and sensory information. In addition, the numerous distributed parallel pathwayspermit multiple avenues to process a given response.Heart–Brain SynchronizationThe third way in which the picture is more complicated is that whereas Wölk and Velden’shypothesis considers only the alpha rhythm, there are other brain rhythms that are alsosynchronized to the heart. These include the beta rhythm as well as lower frequency brainactivity. Thus, it is likely that the effects of macro-scale cardiovascular dynamics on otheraspects of brain activity are also important in contributing to larger fluctuations in performance,such as those observed in the studies reported here.Appendix D presents evidence from a number of studies confirming that a significant amountof alpha rhythm activity is indeed synchronized to the activity of the heart. We have alsopresented additional evidence showing that Wölk and Velden’s contention appears to have anempirical basis, in that we found that the alpha rhythm is synchronized to the cardiac cycle.Moreover, our evidence suggests that alpha synchronization increases duringpsychophysiological coherence and that other brain rhythms—namely, the beta rhythm andlower frequency brain activity—also appear to be synchronized to the cardiac cycle.System Dynamics: Centrality of the Heart in thePsychophysiological NetworkTo this point our concern has been describing the nature, organization, and measurement ofsix different psychophysiological modes. In particular we have focused on thepsychophysiological coherence mode and its impact on various aspects of psychophysiologicalfunction, including pain perception, respiration, emotional processing, and cognitiveperformance. Now we turn to the basic question of system dynamics: how the heart, as the mostpowerful generator of rhythmic information patterns in the body, acts effectively to bind andsynchronize the entire system. This helps explain the mechanisms that underlie the heart’s role inthe generation of system-wide coherence in the body as a whole. In addition to an overview ofresearch in these areas, we also present our own findings, which, so far as we know, represent anoriginal contribution.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Complex living systems, such as human beings, are composed of numerous interconnected,dynamic networks of biological structures and processes. The recent application of systemsthinking in the life sciences has given rise to the understanding that the function of the humanorganism as an integrated whole is determined by the multi-level interactions of all the elementsof the psychophysiological system. The elements influence one another in a network fashionrather than through strict hierarchical or cause-effect relationships. Thus, any node within thepsychophysiological network—any organ, system, substance, or process—necessarily exerts animpact, whether pronounced or subtle, on the functioning of the system as a whole. And whilecertain nodes have a greater influence than others in a given network at a particular level ofsystem organization, those nodes that constitute multi-level linkages across different subsystemsand scales of organization will have a greater influence on the system as a whole. Abundantevidence indicates that proper coordination and synchronization—i.e., coherent organization—among the lateral and vertical networks of biological activity generated by these structures andsubsystems is critical for the emergence of higher-order functions.As we have seen thus far, one of the primary ways that information is encoded andcommunicated throughout our psychophysiological systems is in the language of dynamicpatterns. In the nervous system, for example, it is well established that information is encoded inthe time interval between action potentials—and, on a macro-scale, in the intervals betweenbursts of neural activity. Likewise, in the endocrine system, patterns of “pulses” of hormonerelease are used to convey biologically relevant information. This is an important principle ofoperation, as it appears that the body uses this same encoding and transmission strategy—encoding information in the time intervals between pulses of activity—in many systems andacross very different time scales. This is biologically efficient in that the body is organized to usea common information communication mechanism across multiple systems.There is substantial evidence that the heart plays a unique role in synchronizing the activity inmultiple systems of the body and across different levels of organization, and thus in orchestratingthe flow of information throughout the psychophysiological network. As the most powerful andconsistent generator of rhythmic information patterns in the body, and possessing a far moreextensive communication system with the brain than other organs, the heart is in continuousconnection with the brain and other bodily organs and systems through multiple pathways:neurologically (through the transmission of neural impulses), biochemically (through hormonesand neurotransmitters), biophysically (through pressure and sound waves), and energetically(through electromagnetic field interactions).As we discuss each of these main communication pathways in more detail, it will becomeclear that the heart is a central node in the psychophysiological network that influences multiplesystems, and is thus uniquely positioned to integrate and communicate information both acrosssystems and throughout the whole organism. Because of the extensiveness of the heart’sinfluence on the physiological, cognitive, and emotional systems, the heart provides a point ofaccess from which the dynamics of bodily processes can be quickly and profoundly affected.From this perspective, we will also see how intentional interventions that increase coherence inINTEGRAL REVIEWDecember 2009Vol. 5, No. 2the heart’s rhythms can facilitate a rapid shift to the psychophysiological coherence mode, withprofound system-wide consequences.In the light of these ideas, we can now postulate that information relative to global-scaleintegration (the organization and function of the body as whole) is encoded in the interbeatintervals of the heartbeat. Thus, the heart effectively acts as the central “conductor” of rhythmicactivity in the body: the neural, hormonal, biophysical, and energetic patterns generated by theheart’s rhythmic activity provide a global synchronizing signal for the system as a whole.Neurological InteractionsOf all the organs in the body, the heart has the most extensive neural connection with thebrain. Until relatively recently, much attention in biology has been focused on understandinghow the brain regulates all organs in the body, including the heart. However, as discussed above,more recent understandings have begun to portray quite a different picture, in which the heartactually exerts a significant influence on the brain. In this section we describe the various waysin which the heart affects the brain and body via neurological pathways, and we examine inparticular its influence on the activity and function of higher brain centers and processes. In orderto understand this heart–brain relationship, it is necessary, first, to review some recent findingsof how the brain processes information and how the organization of neurological activity iscritical to brain function. This organization can be described in terms of the three concepts ofcoherence introduced at the beginning of this article: coherence as global order, asautocoherence, and as cross-coherence.The brain is often analogized to the functions of a computer. But in terms of informationprocessing and computation the brain is nothing like a digital computer. It does not assemblethoughts and feelings from digitized bits of serial data. Rather, the brain is more like an analogprocessor that relates whole patterns and concepts to one another; it looks for similarities,differences, or relationships between them. The brain is a highly efficient processor and analyzerof information that is exquisitely sensitive to novelty—to rate of change and to the differencebetween patterns.At the macro-level of organization, global coherence must be present in order for the brainand nervous system to function efficiently and effectively. This means that the neural activity,which encodes information, must be stable and coordinated. It also means that the variouscenters within the brain must be able to dynamically synchronize their activity in order forinformation to be smoothly processed and perceived.For example, autocoherence and cross-coherence in the electrical activity of diverse regionsof the brain are necessary for sensory perception to occur. Our “coherent” perception of an objectin the external world actually comes from millions of units of fragmented sensory informationthat are made globally coherent by being brought together and organized into a single consciousexperience.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2A depiction of such macro-scale organization of neural activity is offered by studies using theelectroencephalogram (EEG), which measures macro-scale activity occurring in the dendriticfields of the neurons. These fields reflect excitatory or inhibitory synaptic action over a largenumber of neurons. (A single scalp electrode provides estimates of synaptic action averaged overtissue masses containing between 10 million and 1 billion neurons.) There is a voluminousliterature concerning the relations between the different brain rhythms found in the EEG and themany different aspects of cognition.13 For example, the alpha rhythm amplitude is lower duringmental calculations while the beta rhythms increase (Nunez, 2000).Recent research has focused on the global organization of cooperative workings of local andregional cell groups in order to better understand the brain’s dynamic complexity. At anoperational level, coherence in this context is a specific quantitative measure of functionalrelations between paired locations. In general, this research has shown that separate regions inthe brain can exhibit high coherence in specific frequency bands and, at the same time, lowcoherence in other bands. The resulting correlated activity between these brain regions is cross-coherence, which is thought to emerge either from direct neural connections between the regions,common input from the thalamus and other neocortical regions, or both (Nunez, 2000).However, cross-coherence also occurs between distant cortical structures that are not necessarilyinterconnected anatomically (Bressler, Coppola, & Nakamura, 1993). This raises the question ofwhat other mechanisms might account for this communication among distant brain regions.A notable example of such cross-coherence has been described by Rodolfo Llinas, Chief ofPhysiology and Neuroscience at the New York University School of Medicine. He observed thatspecific areas of the cortex emit a steady oscillation, at a frequency of around 40 cycles persecond (40 Hz). He also found that remote areas of the cortex were phase-locked at this 40-Hzfrequency, meaning that the waves they produced all oscillated in synchrony. This led Llinas andothers to suggest that the neurons perform in synchrony because they follow a kind of conductor(Ratey, 2001).The prime candidate for the brain’s internal conductor is the many intralaminar nuclei, locatedwithin the thalamus. These nuclei receive and project long axons to many areas of the brain.They take in information, reply to it, and monitor the responses to their replies, thus creatingelaborate feedback loops in which resonant activity (~40 Hz) is modified by incoming sensoryinput. If the intralaminar nuclei are damaged, the person enters a deep and irreversible coma.Indeed, it appears that it is only when the “conductor” synchronizes the brain’s activity that webecome conscious. When this happens with a sufficient number of neural networks, theoscillations become ordered and globally coherent. As they spread their influence, recruitingmore networks to join them, consciousness arises (Ratey, 2001).The thalamus appears to play an active role in the generation of all the global EEG rhythms,and it should be emphasized that phase synchrony has been shown to occur in all the frequencyThe main rhythms that have been identified are: the delta rhythm (0–4 Hz), the theta rhythm (4-8 Hz),the alpha rhythm (8-12 Hz), the beta rhythm (12-16 Hz), and most recently the gamma rhythm (~ 40 Hz).INTEGRAL REVIEWDecember 2009Vol. 5, No. 2bands found in the EEG, not just in the 40 Hz band. 14 For example, different types ofsynchronization occur in the alpha band during the different phases of memory processes(encoding and retrieval) (Fingelkurts, Krause, Kaplan, Borisov, & Sams, 2003), and cross-coherence increases in the theta band during mental calculations (Nunez, 2000). Coherence inthe alpha band is also correlated to perceptual and decision-making processes, and it increases inthe frontal cortex during task processing (Kolev, Yordanova, Schurmann, & Basar, 2001).The organization of the many interconnected neural networks within the brain allows formaximal flexibility in adapting to changing demands, such as focus on an external sensory inputor an internal process. However, the degree of coupling, which regulates synchronized activity inthe network, varies depending on the needs of the moment. When the network is eitherexcessively coupled or is too loosely coupled, the system is less able to dynamically recruit theappropriate neural support systems it needs to respond to a particular demand. For example, thealpha rhythm increases in amplitude and distribution when the neural populations in the brain aremore tightly coupled, which occurs when the brain regions involved are not processinginformation. Under these circumstances cognitive performance is reduced, especially thatinvolving the processing of external sensory information. In terms of optimizing performance,this means in general that one should not be too relaxed (increased coupling) or overlystimulated (decreased coupling). Thus, in the light of the results of our studies of cognitiveperformance and heart-brain synchronization discussed above, the psychophysiologicalcoherence mode appears to be a condition under which optimal coupling, and thus improvedperformance, occurs across diverse systems in the body.Relevant to this discussion are the findings from a recent study of long-term Buddhistpractitioners. This study found that while the practitioners generated a state of “unconditionalloving-kindness and compassion,” increases in gamma band oscillation and long-distance phasesynchrony were observed (Lutz, Greischar, Rawlings, Ricard, & Davidson, 2004). The study’sauthors suggest that the large increase in gamma band synchrony reflects a change in the qualityof moment-to-moment awareness. Moreover, because the characteristic patterns of baselineactivity in these long-term meditators were found to be different from those of a control group,the results suggest that an individual’s baseline state can also be altered with long-term practice.The authors of this study describe the Buddhist meditation as an “objectless meditation” inwhich the practitioners do not directly attend to a specific object or the breath, but focus insteadon cultivating a feeling of “unconditional loving-kindness and compassion.” In many ways, thefocus of this practice is comparable to the focus of the Heart Lock-In technique of the HeartMathsystem. It would therefore be interesting to investigate whether HeartMath practitioners, when ina state of psychophysiological coherence, also produce the increases in gamma-band oscillationThe electroencephalogram (EEG) provides a very large-scale measure of the activity occurring in thedendritic fields of the neurons. These fields reflect the excess of excitatory or inhibitory synaptic actionover a large number of neurons. A single scalp electrode provides estimates of synaptic action averagedover tissue masses containing between 10 million and 1 billion neurons. Synchronizations of oscillatoryneural discharges are thought to play a crucial role in the constitution of transient networks that integratedistributed neural processes into highly ordered cognitive and affective functions that can induce synapticchanges.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2and long-distance phase-synchrony observed in this study. Although this study did not measureheart rhythm coherence, another study of Buddhist monks using the same meditative focus of“loving-kindness and compassion” found an increase in heart rhythm coherence during thispractice (Rapgay, n.d.). Because these studies were both conducted with samples of Buddhistmonks who were practicing the same meditative focus, this raises the possibility that heartrhythm coherence and increased gamma-band phase synchrony are linked in a deeper way. Thisis consistent with the hypothesis that heart rhythm coherence reflects a state of increased globalcoherence in the body’s function as a whole.In summary, the mechanisms that underlie the source of oscillatory rhythms in the thalamusare complex, and there are a number of different hypotheses concerning these. The mechanismsresponsible for the synchronization of remote cells in the brain are even more complex, as thereare both local and global levels of synchronization and also interactions between the local andglobal levels. Whatever the mechanisms turn out to be that facilitate synchronous activity inremote cell assemblies, it is clear that the input from the heart to the brain affects the activity ofthe thalamus and its ability to synchronize cortical activity. This is important in understandingthe relationship between global coherence, emotional stability, and optimal performance.Over the past several decades, several lines of scientific evidence have established that, farmore than a mechanical pump, the heart functions as a sensory organ and as a complexinformation encoding and processing center. Groundbreaking research in the relatively new fieldof neurocardiology has demonstrated that the heart has an extensive intrinsic nervous system thatis sufficiently sophisticated to qualify as a “little brain” in its own right. Pioneer neurocardiologyresearcher Dr. J. Andrew Armour first described the anatomical organization and function of theheart brain in 1991 (Armour, 1991). Containing over 40,000 neurons, its complex circuitryenables it to sense, regulate, and remember. Moreover, the heart brain can process informationand make decisions about cardiac control independent of the central nervous system (Armour,2003; Armour & Kember, 2004).The heart brain senses hormonal, heart rate, and blood pressure signals, translates them intoneurological impulses, and processes this information internally. It then sends the information tothe central brain via afferent pathways in the vagus nerves and spinal column. When differenthormones or neurotransmitters in the bloodstream are detected by the sensory neurites in theheart, the pattern in the afferent neural output sent to the brain is modified (Armour, 1994). Inother words, in addition to its better-known functions, the heart is also a sensory center thatdetects and transmits information about the biochemical content of the regional blood flow.Neurological signals originating in the heart have an important and widespread influence inregulating the function of organs and systems throughout the body. For example, it is nowknown that in addition to modulating the activity of the nervous and endocrine systems, inputfrom the heart influences the activity of the digestive tract, urinary bladder, spleen, respiratoryand lymph systems, and skeletal muscles (Chernigovskiy, 1967). In more specific terms,cardiovascular afferent signals regulate efferent ANS outflow, (Grossman, Janssen, & Vaitl,1986) modulate pain perception (Randich & Gebhart, 1992) and hormone production (DrinkhillINTEGRAL REVIEWDecember 2009Vol. 5, No. 2& Mary, 1989), and influence the activity of the locus coeruleus and that of the pyramidal tractcells in the motor cortex (Coleridge et al., 1976; Svensson & Thoren, 1979). Also, spinal cordexcitability varies directly with the cardiac pulse, as does physiological tremor of normal skeletalmuscles (Forster & Stone, 1976).Beyond the key role of cardiac afferent signals in physiological regulation, our earlierdiscussion also illuminates the heart’s significant influence on perceptual and cognitive functionvia its input to higher brain centers. Our discussion has thus far covered behavioral data showinga relationship between the heart’s input and cognitive performance, as well aselectrophysiological studies demonstrating the synchronization of brain activity to the heart.Beyond these findings, there is also a considerable body of other electrophysiological evidencedemonstrating the modulation of higher brain activity by cardiovascular afferent input (see Lacey& Lacey, 1970; McCraty, 2003; and Sandman et al., 1982, for reviews).Experiments carried out in Germany by psychophysiologist Rainer Schandry havedemonstrated that afferent input from the heart evokes cortical responses analogous to “classical”sensory event-related potentials. These experiments have shown that afferent input from thecardiovascular system is accompanied by specific changes in the brain’s electrical activity.Schandry and colleagues found, as have we, that this activity is most pronounced at thefrontocortical areas, a region particularly involved in the processing of visceral afferentinformation. In addition, psychological factors such as attention to cardiac sensations, perceptualsensitivity, and motivation have been found to modulate cortical heartbeat evoked potentials in afashion analogous to the cortical processing of external stimuli (Lader & Mathews, 1970;Montoya, Schandry, & Muller, 1993; Schandry & Montoya, 1996; Schandry, Sparrer, &Weitkunat, 1986). In our own study, in which we investigated the electrophysiology ofinformation processing in relation to intuition, we also found that the heart’s afferent inputsignificantly modulates frontocortical activity, especially during the psychophysiologicalcoherence mode (McCraty et al., 2004a, 2004b).The observation that the heart’s afferent input modulates frontal activity is concordant withother findings that activity in the prefrontal cortex covaries with changes in the heart rhythm(Lane et al., 2001). This is consistent with the biological principle of reciprocal connections inneural systems. Therefore, in addition to the well-established routes (e.g., the thalamic pathway)by which cardiovascular afferent signals modulate higher cortical function, there may well beadditional routes from the heart to the prefrontal cortex.Biochemical InteractionsIn addition to its extensive neurological interactions with the brain and body, the heart alsocommunicates with the brain and body biochemically, by way of the hormones it produces.Although not typically thought of as an endocrine gland, the heart in fact manufactures andsecretes a number of hormones and neurotransmitters that have a wide-ranging impact on bodyas a whole.The heart was reclassified as part of the hormonal system in 1983, when a new hormoneproduced and secreted by the atria of the heart was discovered. This hormone has been variouslyINTEGRAL REVIEWDecember 2009Vol. 5, No. 2termed atrial natriuretic factor (ANF), atrial natriuretic peptide (ANP), or atrial peptide.Nicknamed the “balance hormone,” and playing an important role in fluid and electrolytehomeostasis, it exerts its effects on the blood vessels, kidneys, adrenal glands, and many of theregulatory regions of the brain (Cantin & Genest, 1985, 1986). In addition, studies indicate thatatrial peptide inhibits the release of stress hormones (Strohle, Kellner, Holsboer, & Wiedemann,1998), reduces sympathetic outflow (Butler, Senn, & Floras, 1994), plays a part in hormonalpathways that stimulate the function and growth of reproductive organs (Kentsch, Lawrenz, Ball,Gerzer, & Muller-Esch, 1992), and may even interact with the immune system (Vollmar, Lang,Hanze, & Schulz, 1990). Even more intriguing, experiments suggest that atrial peptide caninfluence motivation and behavior (Telegdy, 1994).Several years following the discovery of atrial peptide, a related peptide hormone with similarbiological functions was identified. This was called brain natriuretic peptide (BNP) because itwas first identified in porcine brain. It soon became clear, however, that the main source of thispeptide was the cardiac ventricle rather than the brain, and brain natriuretic peptide is nowsometimes called B-type natriuretic peptide (Mukoyama et al., 1991).Armour and colleagues also found that the heart contains a cell type known as intrinsiccardiac adrenergic cells. These cells are so classified because they synthesize and releasecatecholamines (norepinephrine, epinephrine, and dopamine), neurotransmitters once thought tobe produced only by neurons in the brain and ganglia outside the heart (Huang et al., 1996).More recently still, it was discovered that the heart also manufactures and secretes oxytocin,commonly referred to as the “love” or social “bonding hormone.” Beyond its well-knownfunctions in childbirth and lactation, recent evidence indicates that this hormone is also involvedin cognition, tolerance, trust, complex sexual and maternal behaviors, as well as in the learningof social cues and the establishment of enduring pair bonds. Remarkably, concentrations ofoxytocin produced in the heart are in the same range as those produced in the brain (Gutkowskaet al., 2000).In a preliminary study (10 participants), we examined changes in the blood concentrations ofoxytocin and atrial peptide before and after 10 minutes of maintaining the psychophysiologicalcoherence mode, which was generated by a loving emotional focus. While an increase inoxytocin was observed for the whole sample, it was not statistically significant, although it likelywould have been with a larger sample. On the other hand, despite the small number of cases, thedecrease in atrial peptide was significant. As atrial peptide release is an index of the stretch andcontractile force of the atrial wall of the heart, these data suggest that cardiovascular efficiencyincreases during the psychophysiological coherence mode. The results for the male and femalesubgroups in this study are shown in Figure 6.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Heart Hormones Before and After CoherenceFigure 6. Oxytocin and atrial peptide changes during heart rhythm coherence. Graphs showchanges in blood levels of oxytocin and atrial peptide for male and female subgroups from aresting baseline mode to after maintaining the coherence mode for 10 minutes.In addition to changes in the amount of a heart hormone released into the blood affectingcellular and psychological systems, there is also evidence that the temporal pattern of thehormonal release has substantial effects independent of the amount of the hormone released. Ithas been known for some time that neurotransmitters, hormones, and intracellular “secondmessengers” are released in a pulsatile fashion. Pulsatile patterns of secretion are observed fornearly all of the major hormones, including ACTH, GH, LH, FSH, TSH, prolactin, beta-endorphin, melatonin, vasopressin, progesterone, testosterone, insulin, glucagon, renin,aldosterone, and cortisol, among many others.Recent studies by German endocrinology researchers Georg Brabant, Klaus Prank, andChristoph Schofl have shown that, in much the same way that the nervous system encodesinformation in the time interval between action potentials, biologically relevant information isalso encoded in the temporal pattern of hormonal release, across time scales ranging fromseconds to hours (Schofl, Prank, & Brabant, 1995). As most heart hormones are released insynchronicity with the contractions of the heart, there is a rhythmic pattern of hormonal releasethat tracks the heart rhythm.This is particularly relevant to our discussion of coherence, as it suggests that changes in heartrhythm patterns—such as those generated during psychophysiological coherence—impact thebrain and body in yet another way: that is, they change the pattern of hormonal pulses releasedby the heart. Although the influence of these changes in hormonal pulse patterns on biological,emotional, and behavioral processes is still unknown, it is likely that the transmission of suchhormonal information constitutes another pathway by which the effects of psychophysiologicalcoherence on health, well-being, and performance are mediated.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2With every beat, the heart generates a powerful pressure wave that travels rapidly throughoutthe arteries, much faster than the actual flow of blood. These waves of pressure create what wefeel as our pulse. The heart sounds, generated by the closing of the heart valves and cardiacmurmurs, can be heard all over the chest and can extend as far as the groin. Similarly, thepressure waves traveling through the arteries and tissues can affect every organ in the body,especially when the mechanisms that control blood pressure are compromised. In fact, thephysical shock wave generated by the heartbeat expands the chest wall to such an extent that theheartbeat can be detected by measuring the chest expansion (this is called theballistocardiogram).Important rhythms also exist in the oscillations of blood pressure waves. In healthyindividuals, a complex resonance occurs between blood pressure waves, respiration, and rhythmsin the ANS. Because pressure wave patterns vary with the rhythmic activity of the heart, theyrepresent yet another language through which the heart can communicate with the rest of thebody. In essence, all of our cells sense the pressure waves generated by the heart and aredependent upon them in more than one way. At the most basic level, pressure waves force theblood cells through the capillaries to provide oxygen and nutrients to the cells. In addition, thesewaves expand the arteries, causing them to generate a relatively large electrical voltage. Thewaves also apply pressure to the cells in a rhythmic fashion, causing some of the proteinscontained therein to generate an electrical current in response to the “squeeze.”Experiments conducted in our laboratory have shown that a change in the brain’s electricalactivity can be seen when the blood pressure wave reaches the brain, around 240 millisecondsafter the contraction of the heart. An example is shown in Figure 7.Figure 7. Evoked potentials in the EEG due to effects of the blood pressure wave. The toptrace is the EEG recorded at the Cz location, and the middle trace is the blood pressure wave,INTEGRAL REVIEWDecember 2009Vol. 5, No. 2detected at the earlobe. Note that the blood pressure wave arrives at the brain around 240milliseconds after the heartbeat, and a positive shift in the evoked potential in the EEG can beclearly seen upon its arrival.We hypothesize that, in a similar manner to the encoding of information in the space betweennerve impulses and in the intervals between bursts of hormonal activity, information is alsocontained in the interbeat intervals of the pressure waves produced by the heart. Given that thesepressure waves can modulate brain activity and affect vital processes even down to the activityof biomolecules at the cellular level, this represents yet another, potentially important pathwayby which information contained in changing heart rhythm patterns orchestrates system-wideeffects.Thus far we have discussed the role of the heart in information processing and communicationin terms of neurological, hormonal, and biophysical interactions. In this section we explore howthe heart also communicates information to the brain and throughout the body viaelectromagnetic field interactions.To understand how communication occurs via these biological fields requires an energeticconcept of information—one in which data about patterns of organization are actually enfoldedinto the waves of energy generated by the body’s activity and distributed throughout the body’selectromagnetic field. This concept is quite different from the “lock and key” concept ofbiochemical interactions, in which communication occurs through the action of biochemicals,such as neurotransmitters, fitting into specialized receptor sites, much like keys open certainlocks (McCraty et al., 1998). To explain how energetic communication occurs in biologicalsystems, we take Pribram’s holographic approach. He believes, as we do, that thecommunication of energetic information in biological systems is best understood in the terms ofthe information processing principles of holographic theory (McCraty et al., 1998; Pribram,1991; Pribram & Bradley, 1998).Of all the organs, the heart generates by far the most powerful and most extensive rhythmicelectromagnetic field produced in the body. When electrodes placed on the surface of the bodyare used to measure the ECG, it is the electrical component of the heart’s field that is detectedand measured. This electrical voltage, about 60 times greater in amplitude than the electricalactivity produced by the brain, permeates every cell in the body. Thus, the ECG can be detectedby placing electrodes anywhere on the body, from the little toe to the top of the head. Themagnetic component of the heart’s field, which is approximately 5,000 times stronger than themagnetic field produced by the brain (Russek & Schwartz, 1996), is not impeded by the body’stissues and easily radiates outside of the body. This field can be measured several feet away fromthe body with sensitive magnetometers (McCraty et al., 1998). These energetic emanations andinteractions provide a plausible mechanism for how we can “feel” or sense another person’spresence and even their emotional state, independent of body language and other signals(McCraty, 2004).INTEGRAL REVIEWDecember 2009Vol. 5, No. 2The heart’s ever-present rhythmic field has a powerful influence on communicative processesthroughout the body. As already noted above, brain rhythms naturally synchronize to the heart’srhythmic activity, and the rhythms of diverse physiological oscillatory systems can entrain to theheart’s rhythm. There is evidence that the heart’s field may even play a regulatory role at thecellular level, in that we have found that changes in the cardiac field can affect the growth rate ofcells in culture (McCraty et al., 1998).As can be seen in Figure 20, (Appendix D) the electromagnetic waves generated by the heartare immediately registered in one’s brain waves and can have quite a large effect on the heartbeatevoked potential. This same effect has been observed by Gary Schwartz and colleagues at theUniversity of Arizona, who also suggest that energetic interactions between the heart and brainplay an important role in psychophysiological processes (Russek & Schwartz, 1994, 1996; Song,Schwartz, & Russek, 1998).Energetic Signatures of Psychophysiological ModesOur research has shown that information about a person’s emotional state is alsocommunicated throughout the body and into the external environment via the heart’selectromagnetic field (McCraty et al., 1998). As described earlier, the rhythmic beating patternsof the heart change significantly as we experience different emotions. Thus, negative emotions,such as anger or frustration, are associated with an erratic, incoherent pattern in the heart’srhythms, whereas positive emotions, such as love or appreciation, are associated with a sine-wave-like pattern, denoting coherence in the heart’s rhythmic activity. In turn, these changes inthe heart’s beating patterns create corresponding changes in the frequency spectra of theelectromagnetic field radiated by the heart.This is observed when spectral analysis techniques are applied to the energy waveformsgenerated by the heart (ECG or MCG) in the same way that is typically done when analyzingwaves generated by electrical activity in the brain. Different spectral patterns are correlated bothwith the patterns of beat-to-beat variability and with the current psychophysiological state. Thesespectral patterns can be interpreted as “information patterns” containing data about thepsychophysiological state of the individual in that moment in time. Appendix E shows waterfallplots from the ECG data used to produce the examples of the six different psychophysiologicalmodes described at the outset of this article. These reveal distinctive spectral patterns associatedwith each specific mode.The spectra of ECG recordings in Appendix E illustrate the enormous richness andcomplexity of the heart’s activity and the voluminous density of information encoding andtransmission that occurs, via the movement of energy, in the body’s internal electromagneticenvironment. As already noted, similar patterns of information are encoded in the space (time)between nerve impulses and in the intervals between bursts of hormonal activity and pressurewaves. We propose, further, that information is encoded and communicated in same manner inthe intervals between heartbeats. Such an information encoding strategy would allowcommunication via the neural and hormonal pulses that are produced with each heartbeat andINTEGRAL REVIEWDecember 2009Vol. 5, No. 2also via the electromagnetic waves produced by the heart. As a means by which the heart cantransmit information both throughout the body’s psychophysiological networks and into theexternal environment, the validity of this energetic communication mechanism can beempirically verified. This concept of energetic communication provides the basis for explaininghow information about the organization and state of the system as a whole is distributedthroughout the body in an almost instantaneous way.The heart’s rhythmic energetic activity lies at the center of our account. The heart generates acontinuous series of electromagnetic pulses in which the time interval between pulses varies in adynamic and complex manner. These pulsing waves of electromagnetic energy give rise to fieldswithin fields, which form interference patterns when they interact with magnetically polarizabletissues and structures. In more specific terms, we postulate that as pulsing waves of energyradiate out from the heart, the energy waves interact with organs and other structures to createinterference patterns. At the same time, the endogenous processes in each of the other organs,structures, and systems, including those at the micro-scale of cells and membranes, also generatepatterns of dynamic activity. These patterns of dynamic activity radiate out into the body’sinternal environment as energy oscillations, and they interact with the energy waves from theheart and to some degree with the energy waves of other organs and structures. In each of theseinteractions the energy waves encode the features of the objects and their dynamic activity asinterference patterns. Because the heart generates by far the strongest energy field, whichinteracts with both the macro and micro scales of the body’s organization, the waves it producesoperate effectively as global carrier waves that encode the information contained in theinterference patterns. These global carrier waves thus contain encoded information from all ofthe body’s energetic interactions, and they distribute this information throughout all systems inthe body. In this holographic-like process, the encoded information acts to in-form the activity ofall bodily functions (McCraty et al., 1998). This energetic communication system therebyoperates as a global organizing mechanism to coordinate and synchronize psychophysiologicalprocesses in the body as a whole.This theory—that the heart encodes and distributes energetic information holographically—isbased on the same model that neuropsychologist Karl Pribram has used to describe the neuralprocesses in the brain that gives rise to perception and memory (Pribram, 1971, 1991). In thismodel, as Pribram makes clear, the neural impulses are only relaying information from one partof the brain to another. However, the actual processing of information occurs in the spectraldomain of energy frequency—a domain outside space and time in which the waves of energyproduced by the operation of the neural microstructure interact. Moreover, he has shown that thatthe same mathematics that Gabor (1948) used to describe the quantum-holographic principlesinvolved in the physics of signal processing can also be used to describe the informationprocessing that occurs in the electromagnetic interactions between the dendritic and axon fieldsof neurons (McCraty et al., 1998). While a discussion of this is beyond the scope of this article,Pribram and other brain scientists have presented a large body of compelling experimentalevidence that supports the veracity of Pribram’s bioenergetic model of information processing(King, Xie, Zheng, & Pribram, 1994; McCraty et al., 1998; Pribram, 1971, 1991; Santa Maria etal., 1995). Thus, in addition to the energetic information processing that occurs in the brain, asdescribed by Pribram, we propose that there is also a heart-based global energetic system thatencodes and distributes information to coordinate and organize the function of the body as aINTEGRAL REVIEWDecember 2009Vol. 5, No. 2whole.15 Thus, in addition to the energetic information processing that occurs in the brain, asdescribed by Pribram, we propose that there is also a heart-based global energetic system thatencodes and distributes information to coordinate and organize the function of the body as awhole.There is compelling evidence to suggest that the heart’s energy field is coupled to a field ofinformation that is not bound by the limits of time and space. This evidence comes from arigorous experimental study we conducted to investigate the proposition that the body receivesand processes information about a future event before the event actually happens (McCraty et al.,2004a, 2004b). The study’s results provide surprising, even astounding data showing that boththe heart and brain appear to receive and respond to information about a future event. Even moretantalizing is the evidence that the heart appears to receive intuitive information before the brain.This suggests that the heart is directly coupled to a subtle energetic field of ambient informationthat surrounds the body, which, in turn, is entangled and interacts with the multiplicity of energyfields in which the body is embedded—including that of the quantum vacuum.In short, it would appear that we are only just beginning to understand the fundamental role ofa bioenergetic communication system in processing information from sources both within andoutside the body to in-form physiological function, cognitive processes, emotions, and behavior.In this system, it thus seems clear that the energy field of the heart plays a crucial role.The origin of feelings is the body in a certain number of its parts. But now we can godeeper and discover a finer origin underneath that level of description. . .(Damasio, 2003, p. 132)Damasio sums up the current understanding held by many of today’s scientists of the genesisof feelings and emotions. This is the notion that the origin of the particular emotional feelings weexperience in each moment lies in the substrata of our body’s physiological processes. Positivefeelings emerge from body states in which the physiological regulation of the processes of life iseasy and free-flowing, while negative feelings reflect the strain of life processes that are difficultfor the body to balance and that may even be out of control. This general understanding has rootsin an earlier era in psychology and has recently reemerged in the scientific study of emotion.However, the geography of this realm is largely uncharted and has only just begun to be mapped.Needless to say, a more complete understanding awaits development. In this article we have thusendeavored to “go deeper” by offering an account of the “finer origin” of thepsychophysiological processes involved in emotional experience.In “going deeper,” we based our approach on the premise that the body’s physiological,cognitive, and emotional systems are intimately intertwined through ongoing processes involvingreciprocal communication. We hold that an understanding of the workings of these systems mustview their activity as emergent from the dynamic, communicative network of interactingSee also the Appalachian Conferences volumes.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2functions that comprise the human organism. To describe these communicative processes weadopted an information processing perspective. From this viewpoint, communication within andamong the body’s systems is seen to occur through the generation and transmission of rhythmsand patterns of psychophysiological activity. This focus stands in contrast to the traditionalapproach, in which the amount of physiological activity is viewed as the primary basis ofcommunication. We believe a focus on rhythms and patterns of psychophysiological activityilluminates a more fundamental order of information communication—one that signifiesdifferent emotional states, operates to integrate and coordinate the body’s functioning as a whole,and also links the body to the processes of the external world.In order to understand the functional significance of the morphology of patterns ofphysiological activity, we drew on the concept of coherence from the physics of signalprocessing. This is the notion that the degree of efficiency and effectiveness of a system’sfunctioning is directly related to the degree to which there is a harmonious organization of theinteraction among the elements of the system. Thus, a harmonious order in the rhythm or patternof activity signifies a coherent system, whose efficient or optimal function is directly related, inDamasio’s terms, to the “fluidity” of life processes. By contrast, an erratic, nonharmoniouspattern of activity marks an incoherent system, whose function reflects the “strain” of lifeprocesses.In operationalizing this approach, we used the pattern of the heart’s rhythmic activity as ourprimary physiological marker, as it was the most sensitive measure of changes in emotionalstates. In reviewing the results of our empirical research, we identified six psychophysiologicalmodes distinguished by their physiological, mental, and emotional correlates. These are: MentalFocus, Psychophysiological Incoherence, Psychophysiological Coherence, Relaxation, ExtremeNegative Emotion, and Emotional Quiescence. We showed that different emotions are associatedwith different degrees of coherence in the activity of the body’s systems. While positiveemotions such as appreciation, care, and love drive the system toward increased physiologicalcoherence, negative emotions drive the system towards incoherence.In particular, we highlighted the importance of the psychophysiological coherence mode.Associated with the experience of sustained positive emotions, the coherence mode hasnumerous psychological and health-related benefits, which have been demonstrated by a growingbody of research. Of note are the findings showing a direct relationship between this mode andcognitive performance, as well as data linking this mode to intuition.Using our empirical findings as a point of departure, we constructed a typology—a conceptual“map”—of the reality of psychophysiological interaction. We differentiated twelve primarytypes of psychophysiological interaction, distinguished by their values on two theoreticaldimensions. Each type describes a distinctive physiological substratum that underlies a differentprimary emotion or psychophysiological state. Six of the types signify emotional states typicallyexperienced in the course of everyday life. Qualitatively distinct from the feelings of everydaylife are six additional types of psychophysiological interaction. Discontinuous from thepsychophysiological states of day-to-day life, these are hyper-states of extreme emotionsreflecting the body’s response to extraordinary circumstances. One interesting implication of theINTEGRAL REVIEWDecember 2009Vol. 5, No. 2typology is the prediction of four additional hyper-states of psychophysiological interaction,beyond the two hyper-states that we have been able to document empirically.While our findings on the psychophysiological modes showed that the patterns of the heart’srhythmic activity are clearly reflective of different emotional states, in the second part of thisarticle we also presented an account of the heart’s constructive role in the physiologicalprocesses by which emotional experience is generated. According to a model based on Pribram’stheory, emotions result from the “mismatch” between familiar input patterns and current inputpatterns that are different or novel. The heart is the primary source of dynamic rhythmic patternsin the body and possesses extensive communication networks with the brain and other systems.With each beat, it not only pumps blood, but also transmits patterns of neurological, hormonal,pressure, and electromagnetic information through these networks. These multiple inputs to thebrain from the heart contribute significantly to the familiar reference pattern and also to thosedeviations from the familiar that are experienced as changes in emotions.We also presented evidence showing that the heart has a significant influence on the brain’sneurological activity and even plays a role in modulating cognitive functions. While extensiveevidence had previously established that sensory-motor integration and cognitive processing ismodified by changes in heart rate (beat-to-beat cardiac accelerations and decelerations), ourresearch has expanded this understanding. We found that macro-scale patterns of the heart’srhythmic activity also significantly affect cognitive performance and intentional behavior wellbeyond the micro-scale effects previously reported. We also demonstrated a significantrelationship between heart rhythm patterns and cognitive performance, in that increased heartrhythm coherence leads to improved cognitive performance.This along with other findings led us to propose that a global level of organization serves tobind and synchronize the body as a whole. In this function we believe that the heart is a keyorgan in orchestrating activity across multiple systems, encompassing both micro and macrolevels of organization. We proposed that information is encoded in the interbeat intervals of thewaveforms of neurological, hormonal, pressure, and electromagnetic activity generated by theheart. Because of the heart’s wide-ranging linkage to the body’s major systems, informationencoded in the heart’s rhythmic patterns both reflects and influences the ongoing dynamics of thebody as a whole. Furthermore, when the heart’s rhythmic activity shifts into coherence,synchronization and harmonious interaction within and among systems is the result. This, in turn,produces optimal states of health, physical activity, and cognitive performance. Thus, the heart isa critical nodal point in the psychophysiological network: it acts as the conductor in the humansymphony, setting the beat that binds and synchronizes the entire system.An important, though little investigated, way in which the heart acts as a global conductor isthrough its electromagnetic interactions. We proposed that the electromagnetic fields producedby the heart form a complex energetic network that connects the electromagnetic fields of therest of the body. In doing so, the heart’s energetic field acts as a modulated carrier wave thatencodes and communicates information throughout the entire body, from the systemic to thecellular levels, and even conveys information outside the body between individuals. In theseways it provides a global signal that integrates the order of the system as a whole.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2The concept of an energetic information field is not a new one. Indeed, many prominentscientists have proposed models in which information from all physical, biological andpsychosocial interactions is enfolded as a spectral order outside the space/time world in theenergy waveforms of the quantum vacuum. Holographic principles (Gabor, 1948) form the basisof most of these theories and have been used to describe how information about the organizationof a whole is nonlocalized—enfolded and distributed to all parts and locations via the energywaveforms produced by interactions in the brain, (Pribram, 1971, 1991) social structures,(Bradley, 1987; Bradley & Pribram, 1998) and the universe (Bekenstein, 2003; Nadeau &Kafatos, 1999). We adopted a holographic perspective to describe how energy waveformsgenerated by the heart’s electromagnetic field encode and distribute information about allstructures and processes throughout the body from the cellular level to the body as a whole.Moreover, the energy fields produced by the heart and other bodily structures are transmittedexternally. And because these energy fields are in continuous interaction with the multiplicity ofenergy fields in the environment, it appears that information about nonlocal events and processesis conveyed back to the body and processed as intuition.We believe that the concept of energetic information holds promise as a way of understandinghow the body’s bioenergetic communication system operates to process information fromsources both within and outside the body. Based on the evidence we have presented, it seemsclear that the energy field of the heart plays a crucial role in in-forming physiological function,cognitive processes, emotions, and behavior.We have endeavored to present a deeper understanding of the central significance of the heartin virtually all aspects of the body’s function. As a principal and consistent source of rhythmicinformation patterns that impact the physiological, cognitive, and emotional systems, the heartthus provides an access point from which a change in system-wide function can be immediatelyeffected. When positive emotions are used to shift the heart’s pattern of activity into coherence, aglobal transformation in psychophysiological function occurs. As the evidence we havepresented clearly shows, this transformation results in increased physiological efficiency, greateremotional stability, and enhanced cognitive function and performance. As a simple and directmeans by which one can shift into a state of psychophysiological coherence, the HeartMath toolsare a highly effective method to facilitate this transformation. In the case of Chris, with which weopened this article, the use of these tools proved to be a life-saving and life-changingintervention, leading to changes not only in his physical health, but also in his emotional life,work performance, and relationships. We believe that the growing use of these and similar heart-based tools around the globe by educators and students, health care workers and patients, andmanagers and employees, among others, can play a significant part in improving the “lifeprocesses” of humankind.