Interoceptive sensitivity and self-reports of emotional experience.

People differ in the extent to which they emphasize feelings of activation or deactivation in their verbal reports of experienced emotion, termed arousal focus (AF). Two multimethod studies indicate that AF is linked to heightened interoceptive sensitivity (as measured by performance on a heartbeat detection task). People who were more sensitive to their heartbeats emphasized feelings of activation and deactivation when reporting their experiences of emotion over time more than did those who were less sensitive. This relationship was not accounted for by several other variables, including simple language effects. Implications for the role of interoception in experienced emotion and the validity of self-reported emotion are discussed.

Related papers:

title: Core affect, prototypical emotional episodes, and other things called emotion: dissecting the elephant.
abstract: What is the structure of emotion? Emotion is too broad a class of events to be a single scientific category, and no one structure suffices. As an illustration, core affect is distinguished from prototypical emotional episode. Core affect refers to consciously accessible elemental processes of pleasure and activation, has many causes, and is always present. Its structure involves two bipolar dimensions. Prototypical emotional episode refers to a complex process that unfolds over time, involves causally connected subevents (antecedent; appraisal; physiological, affective, and cognitive changes; behavioral response; self-categorization), has one perceived cause, and is rare. Its structure involves categories (anger, fear, shame, jealousy, etc.) vertically organized as a fuzzy hierarchy and horizontally organized as part of a circumplex.

title: Arousal, activation, and effort in the control of attention.
abstract: This review attempts to organize a range of neuropsychological and psycho-physiological data On attention. Three separate, but interacting, neural systems are distinguished: One controls arousal, which is defined in terms of phasic physiological responses to input. The arousal control circuits center on the amygdala. A second system controls activation, which is defined in terms of tonic physiological readiness to respond. The readiness circuits center on the basal ganglia of the forebrain. A third system is discerned which coordinates arousal and activation. This coordinating activity is defined as demanding effort. Its cin;uitry centers on the hippocampus. When arousal, activation, and effort are involved in problem solving, at least two further distinctions can be made. During categorizing, arousal precedes activation; during reasoning, activation precedes arousal. Finally, the review addresses the Question of whether effort in problem solving is to be attributed solely to peripheral muscular factors or whether, in fact, direct monitoring of changes in brain organization (changes in set, attitude, etc.) can be productive of measurable indicators of effort. Pribram presented a series of experiments detailing the effects of hippocampal lesions on problem-solving behavior. The results of these experiments were accounted for by recourse to the concept of experiencing a change in awareness which was interpreted as indicating the involvement of "attention." A continuing interest in problems of attention has been reflected not only in the work reported from our laboratory (a dozen and a half papers) but also in that of many others (see reviews by Mostofsky, 1970; Horn and Hinde, 1970; and Kahneman, 1973). Research has largely been directed to two general paradigms defined by the following operations: (a) recording the occurrence of physiological or behavioral responses against a background of monotonous repetition of We wish to express our gratitude to Muriel Bagshaw for additional data analysis and for allowing us to present her unpublished work in this manuscript, and to Linda Heider and Barbara Honegger for their patient help. sensory events (orienting, vigilance, and habituation) and (b) the invariant (categorizing), or the variable but computable (reasoning), pairing of the outcome of response (reinforcement) to sensory events. An assessment of the data derived from these paradigms (in approximately 200 experiments) has led us to identify three basic at-tentional control processes: One regulates arousal resulting from input; a second controls the preparatory activation of response mechanisms; and a third operates to coordinate arousal and activation, an operation that demands effort. …

title: Cognitive, social, and physiological determinants of emotional state.
abstract: The problem of which cues, internal or external, permit a person to label and identify his own emotional state has been with us since the days that James (1890) first tendered his doctrine that "the bodily changes follow directly the perception of the exciting fact, and that our feeling of the same changes as they occur is the emotion" (p. 449). Since we are aware of a variety of feeling and emotion states, it should follow from James' proposition that the various emotions will be accompanied by a variety of differentiable bodily states. Following James' pronouncement, a formidable number of studies were undertaken in search of the physiological differentiators of the emotions. The results, in these early days, were almost uniformly negative. All of the emotional states experi-

title: Valence Focus and Arousal Focus: Individual Differences in the Structure of Affective Experience
abstract: The structure of affect is well represented as a circumplex. The results of a within-subject longitudinal study of self-reported mood indicate individual differences in the circumplex structure of affective experience. These differences can be captured by two constructs: valence focus and arousal focus. Valence focus is the degree to which individuals attend the hedonic component of their affective experience; arousal focus is the degree to which individuals attend the arousal component of their affective experience. In this study, differences in individuals' attention to the hedonic and arousal components of affective experience were related to observed correlations between specific affective elements, such as ( a) ratings of anxious and depressed mood and (b)Negative Affect and Positive Affect.

title: An approach to environmental psychology
abstract: Environmental psychology, though a fast-growing field, is one of the most difficult to fit into the confines of scientific inquiry. Measuring such subjective data as reactions to color, heat, light, and sound would seem to be an almost impossible task; indeed, until now there has been no theory around which the research in this field could be organized. This volume represents a preliminary effort to identify the relevant variables involved and fit them into a systematic framework. Furthermore, it presents extensive sets of measures for investigating the theory and implementing it in a variety of everyday environments.Basically, the framework outlined here proposes that environmental stimuli are linked to behavioral responses by the primary emotional responses of arousal, pleasure, and dominance. By considering the impact of the environment on these basic emotional responses, the effects of diverse stimulus components within or across sense modalities can be readily compared. An additional concept, information rate, is used to compare the effects of different environments, each with stimulation in many sense modalities. In the final chapters the authors present a series of hypotheses which relate the emotional response variables to a diversity of behaviors such as physical approach, performance, affiliation, and verbally or nonverbally expressed preference.

title: Evidence of Convergent Validity on the Dimensions of Affect
abstract: Despite widely differing methodologies, previous studies on affect (emotion as represented in language) have often obtained what appear to be the same basic dimensions. Whether these similarly named dimensions from different methodologies are actually equivalent was tested here by intercorrelating dimensions obtained from multidimensional scaling, successive-intervals scaling, semantic differential scaling, and factor analysis of verbal self-report data. Results strongly supported the convergent validity of pleasure-displeasure and degree of arousal, but were equivocal on additional dimensions. Separate multidimensional scalings of pleasant, intermediate, and unpleasant affect terms (a) confirmed the presence of an arousal dimension at each level of pleasure and (b) obtained three additional dimensions: control/potency/dominance, depth of experience, and locus of causation. These three dimensions were interpreted as describing not the emotion per se but rather beliefs about the antecedents or consequences of the emotion. In a final study, internal versus external locus of causation was shown to be reliably decoded from emotion-denoting words.

title: Measurement of Activation through Self-Report
abstract: While activation has proved to be a very useful concept in understanding behavior, theoretical and practical problems concerning physiological measurement have reduced its utility. Controlled self-report is suggested as an alternative measurement form, and data from several studies are presented indicating the validity of the Activation-Deactivation Adjective Check List (AD-ACL), an objective self-report measure of transient levels of activation. Factor analytic studies yielded four AD-ACL factors representing different points on a hypothetical continuum. These factors correlated substantially with physiological variables and reflected significant activation changes as predicted from diurnal sleep-wakefulness variations and from an impending college examination. The relative merits of self-report and individual peripheral physiological measures in the assessment of activation are discussed.

title: Multidimensional scaling of emotional facial expressions: Similarity from preschoolers to adults.
abstract: Structural models of emotion represent the fact that we perceive emotions as systematically interrelated. These interrelations may reveal a basic property of the human conception of emotions, or they may represent an artifact that is due to semantic relations learned along with the emotion lexicon. The first alternative was supported by results from a series of scalings of 20 emotional facial expressions, results that could not easily be attributed to word similarity. Similarity data on the facial expressions were obtained from 30 adults and 42 preschoolers. For preschoolers, prior evidence indicates that emotion labels are not readily available; for both groups, we measured similarity without the use of emotion labels by asking subjects to group together people who appear to feel alike. The structure of emotions obtained from both children and adults was as predicted: a roughly circular order in a two-dimensional space, the axes of which could be interpreted as pleasure-disp leasure and arousal-sleepiness. The form and meaning of this structure was supported through two additional scalings of the facial expressions with adults: a multidimension al scaling based on direct ratings of similarity-di ssimilarity, and unidimensional scalings on the pleasuredispleasure and arousal-sleepiness dimensions.

title: Three dimensions of emotion.
abstract: All of you have had to face the problems in the general field of emotion, whether your interest was theoretical or practical. I think you will agree that the field is chaotic. When you try to organize it, perhaps f̂ or presentation in a course, you probaoly follow one of two obvious methods. You can admit that "emotion is only a chapter heading," to quote Madison Bentley; in this case you present a sort of smorgasbord of interesting and important facts, and then go on to clinical cases or to experiments on drives in white rats, depending on your inclination. Or, if you wish a more orderly presentation of the topic, you may build it around some of the many theoretical controversies that stud the history of the field. My preference is for the latter method, and after years of following it in class, I think I am beginning to get a satisfactory integration. Let me run over the major theories, and show how they come together.

title: Facial and vocal expressions of emotion.
abstract: A flurry of theoretical and empirical work concerning the production of and response to facial and vocal expressions has occurred in the past decade. That emotional expressions express emotions is a tautology but may not be a fact. Debates have centered on universality, the nature of emotion, and the link between emotions and expressions. Modern evolutionary theory is informing more models, emphasizing that expressions are directed at a receiver, that the interests of sender and receiver can conflict, that there are many determinants of sending an expression in addition to emotion, that expressions influence the receiver in a variety of ways, and that the receiver's response is more than simply decoding a message.

title: Culture and the categorization of emotions.
abstract: Some writers assume--and others deny--that all human beings distinguish emotions from nonemotions and divide the emotions into happiness, anger, fear, and so on. A review of ethnographic and cross-cultural studies on (a) emotion lexicons, (b) the emotions inferred from facial expressions, and (c) dimensions implicit in comparative judgments of emotions indicated both similarities and differences in how the emotions are categorized in different languages and cultures. Five hypotheses are reviewed: (a) Basic categories of emotion are pancultural, subordinate categories culture specific; (b) emotional focal points are pancultural, boundaries culture specific; (c) emotion categories evolved from a single primitive category of physiological arousal; (d) most emotion categories are culture specific but can be defined by pancultural semantic primitives; and (e) an emotion category is a script with both culture-specific and pancultural components.

title: The Feeling of What Happens: Body and Emotion in the Making of Consciousness
abstract: (2000). The Feeling of What Happens: Body and Emotion in the Making of Consciousness.

title: Individual Differences in Physiological Arousal and Perception of Arousal
abstract: The influence of James's theory of emotions on modern theories of social behavior has been pervasive. Major modifications in Jamesian notions have occurred as a function of methodological, empirical, and theoretical advances in the field of psychology. An expanded but essentially Jamesian arousal-cognition model of arousal-based behaviors is proposed and described briefly. This model takes account of recent advances in psychophysiological research focused on individual differences in stimuli-elicited arousal and the perception of arousal.

title: A biopsychosocial approach to arousal regulation
abstract: Arousal regulation processes underlie a variety of behaviors including strong emotion, stress and coping, and psychopathologies such as panic and hypochondriasis. A multiply determined general model of arousal regulation processes in which individual differences in physiological responsivity and somesthetic perception are key mediating factors is reviewed. Biological, physiological, and psychological (cognitive, personality, and social) influences on these factors are discussed. A program of research testing important aspects of the model is reviewed and the model is updated in light of the research findings. Implications for clinical research are described

title: Arousal, cognition and emotion: an appraisal of two-factor theory
abstract: This paper examines Schachter’s (1964) two-factor theory of emotion and reviews published work which either attempts directly to test the theory, or is relevant to its evaluation. Of the three propositions of the theory, the first, that unexplained arousal can be experienced as different emotions according to cognitive circumstances, is identified as the most distinctive. Any adequate test of the theory, therefore, must address itself to this proposition. Of the few attempts to provide such a test only one has produced even partial support, while two further studies have reported results inconsistent with this proposition. Limited support has been found for the second proposition of the theory, that emotional experience will be labile only in the presence ofunexplained arousal. The third proposition, that emotion will be experiencedonly to the extent that physiological arousal is experienced, has received more empirical support than the other two propositions, but is the least distinctive of the three. The dearth of experimental support for this theory, together with other considerations, suggest that it needs to be modified in some key respects. However, further, more adequate tests of the crucial first proposition are required before substantial theoretical revisions are made.

title: Cognitive effects of false heart-rate feedback.
abstract: This experiment was concerned with some of the cognitive effects of internal events. The objective was to ascertain whether the labeling of emotional stimuli would be affected by information concerning internal reactions. Ss viewed 10 slides of seminude females while hearing sounds that were allegedly their heart beats. 1 group of Ss heard their "heart rates" increase markedly to 5 of the slides and not change to the other 5; a 2nd group of Ss heard a marked decrease in the bogus heart rate to S of the slides and no change to the other S. In comparison with the slides to which Ss did not hear a change in the bogus rate, the slides to which they heard a marked change, whether increased or decreased, were (a) rated significantly more attractive during the experiment proper and during a disguised interview conducted 4-5 wk. later, and (b) chosen significantly more as remuneration for experimental participation. Although there is considerable evidence that emotional states are accompanied by physiological changes (Duffy, 1962; Woodworth & Schlosberg, 1962), until recently there was little indication that these internal events facilitate the development of emotional behavior. Several experiments have now shown that emotional behavior is affected by the experimental manipulation of sympathetic activity. Emotional behavior is more readily learned when the sympathetic nervous system is intact than when it is surgically enervated (Wynne & Solomon, 1955), and more readily manifested during epinephrine-induced states of sympathetic activation than during states of relative inactivation (Latane & Schachter, 1962; Schachter & Singer, 1962; Schachter & Wheeler, 1962; Singer, 1963). In an attempt to account for the influence of autonomic arousal on emotional behavior, Schachter (1964) has emphasized the importance of the cognitive effects of internal events. Within his cognitive-physiological theory of emotion, physiological changes are considered to function as stimuli or cues and are represented cognitively as feelings or sensations. These feelings, in turn, arouse further cognitive activity in the form of attempts to identify the situation that precipi1 This research was conducted at Duke University while the author was a National Institutes of Health Postdoctoral Fellow in the Research Training Program in Sciences Related to the Central Nervous System,

title: Blood, sweat, and tears: individual differences in autonomic self-perception.
abstract: This paper analyzes the role of autonomic activity and its perception in the experience and expression of emotion. A series of experiments is described in which an objective methodology for the assessment of heartbeats is developed and used to test a variety of hypotheses about the relationships among heartbeat perception, arousal, and emotion. The data indicate that there are substantial individual differences in the ability to learn to detect heartbeats. Primary among these individual differences is gender–males appear to learn the discrimination more readily than females. Further, when arousal is induced either by physical or psychological stimuli, accuracy of heartbeat detection is increased. The accuracy of heartbeat detection is also related to self-report of affective experience, and may be subserved by functions of the right cerebral hemisphere. The role of cardiodynamics in heartbeat perception is also discussed.

title: Empirical assessment of visceral self-perception: individual and sex differences in the acquisition of heartbeat discrimination.
abstract: This study had two aims: (a) to test precisely the degree to which subjects can learn to discriminate their own heartbeats and (b) to pursue preliminary data suggesting that males and females differ in their ability to learn such discriminations. A new methodology, based on the theory of signal detection, was employed to evaluate objectively and quantitatively the performance of nine male and nine female subjects. The results confirmed the validity of the new methodology for assessing heartbeat detection and also confirmed earlier observations that males are able to learn to detect their own heartbeats but females are not. The results are discussed with particular reference to implications for viscerally based theories of emotion.

title: The psychology of physical symptoms
abstract: Physical symptoms are fascinating phenomena to examine. We all experience them, use them as signals to guide our behavior, and usually assume that they accurately represent underlying physiological activity. At the same time, we implicitly know that bodily sensations are often vague, ambiguous, and subject to a variety of interpretations. It is not surprising, then, that there is often a disparity between what we think is going on in our bodies and what is objectively occurring. In short, phenomena such as physical symptoms are the stuff of psychology. My own research into physical symptoms started by accident several years ago. In a hastily devised experiment dealing with the effects of noise on behavior, I had to write a post-experimental questionnaire that would be long enough to allow the experimenter time to calibrate some equipment for a later portion of the study. I included some physical symptoms on the questionnaire as fillers. The experiment was a total failure, with the exception of the symptom reports. People's perceptions of symptoms were easily influenced by our manipulations, even though their actual physiological state had not changed. And so began the present inquiry. Despite the pervasiveness, importance, and sheer amount of time and money devoted to discussing and curing common physical symptoms and sensations, very little empirical work has been devoted to examining the psychological and perceptual factors related to sensory experience. Occa sional papers have tested a specific theory, such as cognitive dissonance, wherein physical symptoms served as an interesting dependent measure."

title: Neural systems supporting interoceptive awareness
abstract: Influential theories of human emotion argue that subjective feeling states involve representation of bodily responses elicited by emotional events. Within this framework, individual differences in intensity of emotional experience reflect variation in sensitivity to internal bodily responses. We measured regional brain activity by functional magnetic resonance imaging (fMRI) during an interoceptive task wherein subjects judged the timing of their own heartbeats. We observed enhanced activity in insula, somatomotor and cingulate cortices. In right anterior insular/opercular cortex, neural activity predicted subjects' accuracy in the heartbeat detection task. Furthermore, local gray matter volume in the same region correlated with both interoceptive accuracy and subjective ratings of visceral awareness. Indices of negative emotional experience correlated with interoceptive accuracy across subjects. These findings indicate that right anterior insula supports a representation of visceral responses accessible to awareness, providing a substrate for subjective feeling states.

title: Perception of gastric contractions and self-control of gastric motility.
abstract: The hypothesis was that self-control of a visceral response is dependent on ability to perceive occurrence of the response. Subjects were asked to judge whether or not a signal light coincided with a stomach contraction on each of approximately 200 trials. In a different session heart beat perception was tested by asking subjects to judge whether or not signal light flashes coincided with heart beats. Subjects then were tested for ability to increase and to decrease gastric motility prior to biofeedback training, after which half received 4 hrs of visual feedback while the others practiced without feedback. Control of motility without feedback was subsequently retested. Initially, subjects were unable to control gastric motility, but with feedback they could increase motility on command. Ability to perceive gastric contractions was unrelated to control of gastric motility before, during, or following biofeedback training, indicating that self-control of a visceral response is not dependent on perceptual sensitivity. Perception of stomach contractions correlated significantly (r= .51) with perception of heart beats, suggesting that there may be a generalized tendency to be aware of or to attend to visceral events.

title: Signal-detection outcomes on heartbeat and respiratory resistance detection tasks in male and female subjects.
abstract: Male and female subjects were compared on heartbeat, respiratory resistance, and light-tone signal-detection tasks. Subjects judged whether a series of 10 tones was coincident with their heartbeats; whether an external load added to the airway was either present or absent during targeted inspiratory cycles; and whether a series of 10 light flashes was matched with auditory tones presented following a fixed delay of either 50 or 100 ms. Nonparametric indices of perceptual sensitivity and response bias indicated that men were more sensitive than women on the resistive load task (p < .05) and on the heartbeat task (p = .07). Performance on the light-tone task was virtually identical. All subjects used a stricter criterion on the respiratory resistance task than on either the heartbeat or the light-tone task; women employed a stricter criterion than men on the heartbeat task. The gender differences may be understood in terms of lateralization of central processing of somesthetic sensory information.

title: A test of the validity of the method of constant stimuli as an index of heartbeat detection.
abstract: A heartbeat detection task, based on the method of constant stimuli (MCS), requires participants to judge which of a series of tones presented at different delays following a heartbeat are coincident with the heartbeat. Two experiments were conducted to test the validity of the MCS in assessing individual differences in the ability to detect heartbeat sensations. The first experiment found the MCS to be valid, in that about one-third of subjects met the criterion for classification as heartbeat detectors when the tones were presented with respect to their actual heartbeats, but only one subject met the criterion when the tones were presented with respect to previously recorded heartbeats. The second experiment manipulated the timing of the comparison intervals (i.e., R + 100-600 ms rather than R + 0-500 ms) to examine the validity of the median R-wave to tone interval as an index of temporal location of perceived heartbeats, and found it to be a valid index.

title: Quadratic trend analysis and heartbeat detection
abstract: In heartbeat detection tasks based on the Method of Constant Stimuli (MCS), subjects judge the simultaneity between their heartbeats and stimuli presented at six intervals ranging from 0 to 500 ms after the R-waves on an electrocardiogram. Because research suggests that subjects do not perceive stimuli at 0 or 500 ms as simultaneous, individual performance was indexed with quadratic trend analysis to test for distributions of simultaneity judgments across intervals that peak between 0 and 500 ms. Further, because some tasks use only two intervals, performance was also indexed using intervals of either 0 and 200 ms or 200 and 500 ms. Continuous performance scores from quadratic trend and two-interval analysis tended to correlate more highly with variables previously shown to correlate with heartbeat detection than scores from the commonly-used chi(2) analysis. These findings support the use of both quadratic trend analysis and two-interval tasks for assessing heartbeat detection ability.

title: Visceral perception, anhedonia, and emotion
abstract: Few investigators have attempted to examine empirically the relationship between perception of autonomic arousal and emotional state. According to Jamesian theory, individuals who are more aware of their visceral activity should demonstrate greater affective response to emotion-laden stimuli than individuals who are not viscerally perceptive. Therefore, certain groups of 'unemotional' subjects, such as anhedonics, may report fewer or less intense emotional experiences due to an attenuation or lack of autonomic feedback. Results from studies by Katkin (Psychophysiology, 22, (1985) 125-137) suggest that there is a relationship between induced sympathetic arousal, the perception of that arousal, and the self-report of emotional experience. The present study sought to expand upon these findings by comparing visceral perception (i.e. heartbeat detection) performance and a multi-component assessment of emotion in normal and anhedonic subjects. No correlation was found between anhedonia and visceral perception; however, anhedonics were significantly different from normals across several measures of heart rate, self-report, and facial expressions in response to emotion-eliciting slides, with anhedonics consistently showing emotional hypo-responsiveness. Additionally, subjects who were able to perceive their own heartbeats were found to be more facially expressive than poor perceivers.

title: Heartbeat detection and the experience of emotions
abstract: Although many theories of emotion hypothesise a crucial role for the self-perception of visceral activity, there has been little empirical investigation of the relationship between visceral self-perception and emotion. In this study, 52 undergraduates (19 males, 33 females) performed a heartbeat detection task and were classified as good (n=9) or poor (n=43) heartbeat detectors. Subjects were then presented with sets of two film clips, each targeting one of three different emotional valences (amusement, anger, fear). Subjects reported their affective responses to the clips on 9-point scales indicating intensity and pleasantness. Good detectors reported more intense emotions than poor detectors across all three emotional valences, but no differences were found on pleasantness ratings between the groups. These results suggest that visceral perception plays a role in the experience of the intensity of emotions.

title: Heart beat perception and emotional experience.
abstract: The main assumption of the present study is that emotional experience is coupled to perception of bodily processes. From this it is deduced that individuals who show good perception of heart activity tend to exhibit higher levels of a momentarily experienced emotion (in this case anxiety) and to score higher on the personality trait “Emotional Lability.” The aspect of cardiac awareness considered here is perception of heart beats. Subjects were instructed to count heart beats (only by concentrating on their body but not by taking their pulse) during a signalled time interval and the reported number of beats was then compared to the actual number of beats as extracted from the EKG. Additionally, skin conductance and respiration were recorded. During the experimental task (i.e., counting heart beats) increases in heart rate, respiration rate and number of spontaneous fluctuations in skin conductance were recorded. Groups of good and poor perceivers were formed on the basis of accuracy on the perception task. The two groups did not differ in heart rate; however, in State Anxiety and Emotional Lability, the group of good perceivers had significantly higher scores. The importance of visceroception for emotional experience is pointed out and the relevance for clinical psychology is discussed.

title: Signal detection theory and psychophysics
abstract: Book on statistical decision theory and sensory processes in signal detection theory and psychophysics

title: The critical operating characteristic and the evaluation of expert judgment
abstract: The situation in which an expert makes a judgment or renders an opinion about the occurrence of an event, and the event either occurs or does not, may fruitfully be considered from two points of view: considering the expert as a signal detection system; and considering the consumer of the expert opinion who must decide whether or not to take some specific action based on that opinion. The dual-Gaussian, variable-criterion signal detection model provides a good description of expert behavior and forms the basis for distinguishing between accuracy of the expert and performance of the expert. Accuracy of the expert is defined in terms of the receiver operating characteristic (ROC) and is independent of decision criteria and prior probability of the event. Accuracy is measured either by da or Az. The performance of the expert, on the other hand, depends not only on the accuracy of the expert, but also on both the decision criteria used by the expert and the prior probability of the event. Two new concepts, the critical operating characteristic (COC) and the critical hit rate, HRcr, are introduced to allow the performance of experts to be meaningfully compared. Different ways in which expert judgment may be used by the consumer are also discussed.

title: Heart rate discrimination before and after exercise-induced augmented cardiac activity.
abstract: Although there is little direct evidence available, there is a pervasive assumption that HR is easily detected during periods of physical stress or exertion. It has also been suggested that distance runners are keenly aware of their cardiac functioning. The present study assessed cardiac awareness while at rest and again following vigorous exercise for groups of subjects differing in physical fitness. Thirty-six subjects were solicited and composed groups of Sedentary, Tennis, and Distance Running groups. Each group was composed of equal numbers of male and female subjects. HR awareness was assessed using 35 10-sec discrimination trials. Veridical feedback was composed of light flashes triggered by EKG R-spikes whereas false feedback was composed of flashes at rates 10, 20, or 30 percent above or below their actual rate. At the end of each trial, subjects indicated the degree of certainty of their choice. Discrimination accuracy was measured at rest and again following exercise which raised HR level by 75 percent. Analyses of variance indicated that male runners were significantly more accurate discriminators at rest than any other group. Similar superiority was not shown by the female runners. After exercise, the tennis and sedentary groups showed significant overall increases in awareness during augmented cardiac functioning. Exercise did not produce additional increments in awareness for the male runners. A battery of post experimental questionnaires largely failed to discriminate experimental groups.

title: Laterality, emotionality, and heartbeat perception.
abstract: Recent research on visceral perception has indicated that hemispheric specialization and emotionality may account for individual differences among subjects. The present study was designed to examine the nature of the relationship between hemispheric specialization and emotionality, and the manner in which these variables influence individual differences in visceral perception (i.e., detection of cardiac activity). Male subjects were given 20 questions used to test lateral eye movements. Following the completion of the State-Trait Anxiety Inventory (STAI), Form X-1 (State Anxiety), cardiac awareness was assessed using the Whitehead heartbeat discrimination procedure. Subjects then completed the STAI, Form X-2 (Trait Anxiety), and the Eysenck Personality Inventory. Results indicated that good heartbeat perceivers made significantly more left lateral eye movements (i.e., right hemisphere preferent) than poor perceivers on any of the emotional indicators. It was found, however, that subjects with high scores on two of the three emotional indicators made significantly more left lateral eye movements than subjects with low scores. Additional analyses indicate that respiration rate and subject obesity may affect the ability to detect feedback of cardiovascular function.

title: The effects of payoffs and prior probabilities on indices of performance and cutoff location in recognition memory
abstract: We compared the effects of payoffs and prior probability levels on indices of performance and cutoff location in recognition memory. The performance indices considered were d’ from signal-detection theory and two corrections for guessing from simple threshold models. Shifts in cutoff location of comparable size were found for changes in priors and payoffs. The existence of a memory load and the inclusion of feedback did not affect the extent of shifts in cutoff location. Priors affected the corrections for guessing but did not affect d’. These results indicate that d’ remains the preferred index of performance and that the corrections for guessing are not criterion-free measures. The problem of finding an index of recognition performance appropriate for comparing recall and recognition is discussed, as are alternative explanations for conservative cutoff placement.

title: Development and validation of brief measures of positive and negative affect: the PANAS scales.
abstract: In recent studies of the structure of affect, positive and negative affect have consistently emerged as two dominant and relatively independent dimensions. A number of mood scales have been created to measure these factors; however, many existing measures are inadequate, showing low reliability or poor convergent or discriminant validity. To fill the need for reliable and valid Positive Affect and Negative Affect scales that are also brief and easy to administer, we developed two 10-item mood scales that comprise the Positive and Negative Affect Schedule (PANAS). The scales are shown to be highly internally consistent, largely uncorrelated, and stable at appropriate levels over a 2-month time period. Normative data and factorial and external evidence of convergent and discriminant validity for the scales are also presented.

title: Affect intensity as an individual difference characteristic: A review
abstract: Affect intensity is a stable individual difference characteristic defined in terms of the typical strength of an individual's responsiveness. Evidence is reviewed suggesting that the intensity of an individual's affective responsiveness generalizes across specific emotion categories, implying a general temperament dimension of emotional reactivity and variability. Two methods of assessing affect intensity are evaluated and found to exhibit desirable psychometric properties. Substantive research on the validity of the affect intensity construct is reviewed. Affect intensity is related to a variety of specific personality characteristics, has identifiable antecedents in childhood behavior, and relates to a broad range of cognitive, affective, and health-related consequences. An arousal regulation theory is proposed to account for individual differences in affective response intensity. Other plausible theories are mentioned, and directions for future research are discussed.

title: Relation of heart rate control to heartbeat perception
abstract: The relation of heartbeat perception to voluntary control of heart rate (HR) and to learning of enhanced HR control during feedback was studied in three experiments. In Experiment I heartbeat perception was unrelated to voluntary control of HR but was negatively correlated with HR learning. Experiments II and III showed that heartbeat perception was unrelated to either initial voluntary control or learning and suggested that sampling error accounted for the negative correlation in Experiment I. Experiment I also demonstrated that learned increases in HR are retained for at least 10 weeks following feedback training. Autonomic Perception Questionnaire scores were not predictive of voluntary HR control or learning.

title: A computer program to generate parametric and nonparametric signal-detection parameters
abstract: A computer program is described that calculates parametric and nonparametric signal-detection parameters for sensory sensitivity and response bias. Advantages of this program over previously published programs are discussed.

title: Feeling your body or feeling badly: evidence for the limited validity of the Somatosensory Amplification Scale as an index of somatic sensitivity.
abstract: The Somatosensory Amplification Scale (SSAS) purports to measure the extent to which individuals are sensitive to their bodies. The present study examined the psychometric properties of the SSAS in two studies with university students.



Participants completed the SSAS, various cross-sectional measures of somatic and psychological distress, longitudinal measures of somatic symptoms, daily hassles and mood, and participated in a heartbeat detection task (Study 2 only).



The SSAS was correlated with cross-sectional measures of somatic symptom reporting, but not with somatic symptoms reported on a daily basis nor with an index of interoceptive sensitivity. The SSAS was also correlated with several indices of general distress including anxious and depressive symptoms, daily hassles, and negative emotionality.



Taken together, the results suggest that the SSAS is more likely an index of negative emotionality and general distress than a valid measure of somatic sensitivity per se.

title: Intensity and frequency: dimensions underlying positive and negative affect.
abstract: Research on emotions and several happiness scales suggest that positive and negative affect are strongly inversely correlated. However, work on subjective well-being indicates that over time, positive and negative affect are independent across persons. In order to reconcile this inconsistency, two dimensions are proposed for personal affective structure: the frequency of positive versus negative affect and the intensity of affect. Subjects in three studies completed daily and momentary reports on their moods. In support of the intensity dimension, the correlations between positive and negative intensity were strong and positive in all three studies. The intensities of specific emotions across persons were also highly correlated. Across the three studies the frequency and intensity of affect varied independently. Although average levels of positive and negative affect showed low correlations, this relation became strongly inverse when intensity was partialed out. Thus the intensity dimension helps explain the relative independence of positive and negative affect. In addition, emotional intensity is offered as a new personality dimension that manifests interesting characteristics.

title: The Cognitive Structure of Emotions
abstract: 1.  The study of emotion Types of evidence for theories of emotion Some goals for a cognitive theory of emotion 2. Structure of the theory The organisation of emotion types Basic emotions Some implications of the emotions-as-valenced-reactions claim 3. The cognitive psychology of appraisal The appraisal structure Central intensity variables 4. The intensity of emotions Global variables Local variables Variable-values, variable-weights, and emotion thresholds 5. Reactions to events: I. The well-being emotions Loss emotions and fine-grained analyses The fortunes-of-others emotions Self-pity and related states 6. Reactions to events: II. The prospect-based emotions Shock and pleasant surprise Some interrelationships between prospect-based emotions Suspense, resignation, hopelessness, and other related states 7. Reactions to agents The attribution emotions Gratitude, anger, and some other compound emotions 8. Reactions to objects The attraction emotions Fine-grained analyses and emotion sequences 9. The boundaries of the theory Emotion words and cross-cultural issues Emotion experiences and unconscious emotions Coping and the function of emotions Computational tractability.

title: Analysis of individual differences in multidimensional scaling via an n-way generalization of “Eckart-Young” decomposition
abstract: An individual differences model for multidimensional scaling is outlined in which individuals are assumed differentially to weight the several dimensions of a common “psychological space”. A corresponding method of analyzing similarities data is proposed, involving a generalization of “Eckart-Young analysis” to decomposition of three-way (or higher-way) tables. In the present case this decomposition is applied to a derived three-way table of scalar products between stimuli for individuals. This analysis yields a stimulus by dimensions coordinate matrix and a subjects by dimensions matrix of weights. This method is illustrated with data on auditory stimuli and on perception of nations.

title: Similarity Scaling and Cognitive Process Models
abstract: DETERMINISTIC MULTIDIMENSIONAL SCALING APPROACHES ... . . .. ... ....... . 27 Universal Laws of Generalization and Similarity .  Categorization, and Recognition 30 Same-Different Judgments and Reaction Time 37 Cognitive Processes and the Metric Axioms. . . . . ....... . . .. . . . . . . ...... . . . . . .. . . . . . ...... . . . 38 Summary....... . . . . . . . . . . . . . . . ....... . . . . .. . . ....... . . . . . . . .. ........ . . .. .. . . . . . ...... . . . 40 PROBABILISTIC MULTIDIMENSIONAL SCALING APPROACHES . .. . . . . . . . . .. .... . . 41 Probabilistic Scaling of Distance Judgments .. . .. ........ . . . . . ... ..... 41 General Recognition Theory . . . . . . 43 Multivariate Discrimination Methods ..... ... . ....... . . . . . . ......... . . 47

title: Nonmetric individual differences multidimensional scaling: An alternating least squares method with optimal scaling features
abstract: A new procedure is discussed which fits either the weighted or simple Euclidian model to data that may (a) be defined at either the nominal, ordinal, interval or ratio levels of measurement; (b) have missing observations; (c) be symmetric or asymmetric; (d) be conditional or unconditional; (e) be replicated or unreplicated; and (f) be continuous or discrete. Various special cases of the procedure include the most commonly used individual differences multidimensional scaling models, the familiar nonmetric multidimensional scaling model, and several other previously undiscussed variants.The procedure optimizes the fit of the model directly to the data (not to scalar products determined from the data) by an alternating least squares procedure which is convergent, very quick, and relatively free from local minimum problems.The procedure is evaluated via both Monte Carlo and empirical data. It is found to be robust in the face of measurement error, capable of recovering the true underlying configuration in the Monte Carlo situation, and capable of obtaining structures equivalent to those obtained by other less general procedures in the empirical situation.

title: Valence focus and the perception of facial affect.
abstract: Individuals differ in the extent to which they emphasize feelings of pleasure or displeasure in their verbal reports of emotional experience, an individual difference termed valence focus (VF). This multimethod study indicates that VF is linked to heightened efficiency in perceptual processing of affective stimuli. Individuals higher in VF (i.e., who emphasized feelings of pleasure/displeasure in reports of emotional experiences) were more sensitive to changes in negative facial expressions than individuals lower in VF. The effect was not accounted for by current affective state or other personality characteristics. Implications for the validity of self-reported experienced emotion are discussed.

title: Ascending visceral regulation of cortical affective information processing
abstract: Over a century ago, William James proposed that strong emotions represent the perceptual consequences of somato‐visceral feedback. Although the strong form of this conception is no longer viable, considerable evidence has accumulated indicating a range of visceral influences on higher neurobehavioural processes. This literature has only recently begun to consolidate, because earlier reports generally remained at the demonstration level, and pathways and mechanisms for such influences were uncertain. Recently, specific effects of visceral feedback have become apparent on cortical activity, cerebral auditory‐evoked responses, anxiety, memory and behavioural aspects of immunological sickness. Moreover, considerable progress has been made recently in determining the specific neural pathways and systems underlying these actions, especially the role of noradrenergic projections from the nucleus of the tractus solitarius and the locus coeruleus to the amygdala in memory processes, and to the basal forebrain in the processing of anxiety‐related information. The present paper highlights selected recent findings in this area, and outlines relevant structures and pathways involved in the ascending visceral influence on higher neurobehavioural processes.

title: Incremental Validity : a Recommendation
abstract: distinction is to be made between convergent and discriminant validity. It is necessary to demonstrate not only that a measure covaries with certain other connotatively similar variables, but that its covariance with other connotatively dissimilar variables is limited. Campbell (1960) has suggested several possible additions to recommended validity indicators, all of which focus on the problem of discriminant validity, i.e., the demonstration that a test construct is not completely or even largely redundant with other better established or more parsimonious constructs. He has suggested, for example, that correlations with intelligence, social desirability and self-ratings should be reported since these variables are likely to be

title: Interoception: The Inside Story—A Model for Psychosomatic Processes
abstract: To comprehend psychosomatic processes, it will be necessary to understand the brain’s influences on bodily functions and also the body’s afferent sensory input to the central nervous system, including the effects of this input on behavior and cognitive functions, especially emotion. The objective of this Presidential Address is to review what is known circa the year 2000 of the processes and mechanisms of visceral sensory psychobiology, often called interoception.  Over 1000 publications that have appeared since the 19th century were reviewed to prepare this review, including a group that are specifically cited here.  Factors and data were reviewed that were identified as germane to understanding interoception. These included definitional issues, historical roots, the neural basis, studies and results in the cardiovascular-respiratory and alimentary-gastrointestinal systems, studies of emotion, and studies in people with mental disorders. Drug and hormone effects, pain, proprioception, and phantom limb or organ factors, and the role of awareness were briefly described. Methodological issues, methods of study including functional imaging, and possible future directions for study were identified.  Understanding the physical basis of psychosomatic processes, including the so-called mind-body problem, will require a detailed understanding the psychobiology of interoception.

title: Regional Brain Activation Due to Pharmacologically Induced Adrenergic Interoceptive Stimulation in Humans
abstract: Identifying the brain regions associated with visceral sensory activation and awareness (interoception) was a neglected area of neural science until quite recently despite being essential to a comprehensive understanding of psychosomatic processes, baroreception, and higher brain functions such as fear and anxiety, other emotions, and pain.  In this study regional changes in the cerebral metabolic rate for glucose were determined with positron emission tomography in response to cardiovascular-respiratory activation induced in healthy humans by &bgr;-adrenergic stimulation produced with intravenous isoproterenol, which acts predominantly in the periphery because of minimal transport across the blood-brain barrier.  Interoceptive activation raised heart rate to approximately 120 beats per minute, produced somatic and to a lesser extent psychological symptoms, and significantly increased cerebral glucose metabolism in the left primary somatosensory cortex and medial portion of the cingulate gyrus; right insular cortex showed a trend toward an increase that was significant in homogeneous subgroups of right-handed or female subjects.  These results demonstrate the involvement of specific brain regions as well as hemispheric laterality of function in visceral perception, and they suggest that during emotional reactions involving changes in visceral organ function, activation of some of the brain regions observed could be due specifically to interoceptive processes.

title: The relationship between cardiovascular reactivity and heartbeat detection.
abstract: This experiment tested the hypothesis that inotropic cardiovascular reactivity to stress is related to performance on heartbeat discrimination tasks. The experiment also compared the efficacy of a specific modification of two popular heartbeat discrimination paradigms, Whitehead's and Katkin's. Subjects were 48 male undergraduates who performed both discrimination tasks and then were subjected to mental arithmetic stress. Results indicated that high cardiovascular reactors were better detectors than low reactors. Results also indicated that subjects performed better on the modified Whitehead task than on the modified Katkin task.