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 bodys 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 communicationone that both signifies different emotional states, operates tointegrate and coordinate the bodys 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 Damasios 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 coherenceaharmonious state of sustained, self-modulated positive emotionis 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 bodys symphonyto bind and synchronize the entire system. The consistent and pervasive influence of the heartsrhythmic 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 bodys 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