Heartbeat Perception Research Articles

Heartbeat perception and panic disorder: possible explanations for discrepant findings

Results on cardiac awareness in panic disorder are inconsistent. The present study attempted to clarify whether differences in instructions or the inclusion of patients taking antidepressant medication could account for these inconsistencies. 112 patients with panic disorder with agoraphobia were compared to 40 normal controls on the heartbeat perception task developed by Schandry (1981) [Schandry, R., Psychophysiology, 18, 483–488] using a standard instruction (“count all heartbeats you feel in your body”) and a strict instruction (“count only those heartbeats about which you are sure”). Superior heartbeat perception for patients was only found with the standard instruction. Similarly, only with the standard instruction, patients taking medication affecting the cardiovascular system performed worse than patients without medication, as expected based on the relationship between stroke volume and heartbeat perception. The pattern of group differences indicates that agoraphobic patients have a better feeling for how fast their heart is beating than controls although these differences may be due to a tendency to interpret weak sensations as heartbeats. Furthermore, we tested in a subgroup of 40 patients whether cardiac awareness changes with exposure treatment. No changes in heartbeat perception were observed.

A 1-year prospective study of panic attacks: Clinical course and factors associated with maintenance.

A prospective naturalistic 1-year follow-up study of 39 patients with current panic disorder, 17 remitted panic patients, 46 infrequent panickers, 22 patients with simple phobias, and 45 controls assessed clinical course and variables related to the maintenance of panic attacks. Nearly all panic disorder patients (92%) continued to experience panic attacks, and 41% of the initially remitted patients relapsed. No significant effects of treatments delivered in the community were found. Infrequent panickers tended to be more likely to develop panic disorder (15%) than controls (2%). Maintenance/relapse was most consistently linked with good heartbeat perception, anxiety sensitivity, and avoidance in the different subsamples. Patients with simple phobias or normal controls who experienced their first panic attack during follow-up had shown higher anxiety sensitivity at initial assessment than nonpanickers.

The effect of monocular viewing on heartbeat discrimination.

In monocular viewing conditions, an activational imbalance between the cerebral hemispheres was assumed to develop, the direction of which depends on the side of the viewing eye. This assumption was based on the morphological differences between the nasal and the temporal hemiretinas and on physiological data. It was assumed that the hemisphere receiving visual information via the nasal optic fibers, that is, the hemisphere contralateral to the viewing eye, would be the more activated one. Because heartbeat perception is regarded as a predominantly right hemispheric function, it was predicted that during right hemispheric activation created by left monocular viewing heartbeat discrimination performance would be better than during left hemispheric activation created by right monocular viewing. This hypothesis was tested on 30 male right-handed university students who performed a Whitehead-type heartbeat discrimination task while viewing only with the left or with the right eye. Heartbeat perception was more accurate when viewing with the left eye. Additionally, respiratory manipulation during heartbeat discrimination improved performance on this task.

On the relation between cardiodynamics and heartbeat perception.

The mediation of heartbeat perception by cardiodynamic parameters was investigated by experimentally introducing changes in heart performance. Twenty-five subjects (14 women, 11 men) underwent bicycle ergometric exercises (0-75 W) at different tilt angles (90 degrees-0 degree). After each of the 31 tilt/exercise phases, the following measures of cardiac performance were taken using impedance cardiography: stroke volume, Heather Index (as an indicator of contractile force), heart rate, and an estimate of the momentum of the ejected blood mass. Additionally, a heartbeat perception task was performed. The different tilt/exercise combinations induced profound changes in all cardiodynamic measures. The correlation between heartbeat perception and cardiodynamic parameters was highest for "momentum" (r = .67) and for stroke volume (r = .59). From our data, we infer that intraindividually occurring changes in cardiac perception are mediated partially by characteristics of heart dynamics and that the source of these interoceptive signals lies in the heart or in its close vicinity.

Heartbeat perception, instructions, and biofeedback in the control of heart rate

The present study was designed to examine the possibility that individual differences in heartbeat perception and instructions to control heart rate (HR) may influence the acquisition of voluntary control. Good ( n = 20) and poor ( n = 20) perceivers of cardiac activity were selected on the basis of their performance according to Whitehead et al. (1977) heartbeat discrimination procedure. Measures of state and trait anxiety (the State-Trait Anxiety Inventory Form X-1 and Form X-2) and Tellegen's Absorption Scale (TAS) were used to assess emotionality and absorptive ability. Good and poor heartbeat perceivers (a) were given non-motivating instructions to try to either increase or decrease their heart rate (HR) with, or (b) without the use of HR-feedback, and (c) were given motivating instructions to try to either increase or decrease their HR with, or (d) without HR-feedback. Heart rate, skin conductance (SC), and EMG activity were monitored. Subjects were also requested to indicate the cognitive strategies used during their HR control training. No relationship between heartbeat perception and state-trait anxiety measures was found. The results did not support the idea that individual differences in heartbeat perception are related to individual differences in HR-control. They did indicate, however, that motivating instructions improve the capacity to increase or decrease HR. Subjects were able to voluntarily increase or decrease their HRs with or without a feedback signal. However, more pronounced HR increases were obtained in the feedback as compared with the no-feedback condition. SC and EMG activity were in accordance with arousal levels demanded by HR decrease and increase tasks. Subjects used cognitive strategies concerning activation responses during HR-increase and relaxation responses during HR-decrease conditions.

Heartbeat and arrhythmia perception in diabetic autonomic neuropathy

A comparative study of diabetics with autonomic neuropathy (N = 13) as against non-neuropathic diabetics (N = 16) and healthy control persons (N = 20) was carried out with respect to heart rate both at rest and under stress, frequency of cardiac arrhythmias in a 24-h ECG and accuracy of heartbeat and arrhythmia perception. In the subjects with diabetic autonomic neuropathy, the spontaneous variability and stress-induced reactivity of the heart rate as well as the number of tachycardic episodes were reduced, whereas the frequency of ventricular extrasystoles was somewhat increased. Impaired heartbeat perception and a complete loss of perception of arrhythmias as a consequence of neuropathic deafferentation could be demonstrated. Cardiac perception disorders also play a vital role in other clinical problems, e.g. silent myocardial infarction and lack of awareness of hypoglycaemia in diabetes mellitus.

The Effect of Lateral Visual Fixation and the Direction of Eye Movements on Heartbeat Discrimination

This study was undertaken to determine whether the asymmetrical activation of the two cerebral hemispheres affects the accuracy of heartbeat perception. Hemispheric preference--the tendency to activate one hemisphere rather than the other--was assessed by the directionality of conjugate lateral eye movements. Actual differential hemispheric activation was achieved by contralateral visual fixation. The results of 44 right-handed male subjects showed that right hemisphere preferent subjects ("left-movers") performed better on a heartbeat discrimination task than left hemisphere preferent subjects ("right-movers"). The direction of lateral visual fixation also influenced heartbeat discrimination: subjects fixating to the left were more accurate than those fixating to the right.

Enhancement of heartbeat-related brain potentials through cardiac awareness training

Heartbeat synchronous potentials were found to be sensitive to differences in perceptual accuracy. Since heartbeat perception can be improved using appropriate training procedures, increased ability to perceive cardiac performance should also influence heartbeat-related potentials. In the present study, subjects in either of two groups had to press a button immediately after the occurrence of a heartbeat-feedback tone. Whereas the first group was given acoustical heartbeat-feedback throughout the entire training, the second group was provided with tone signals that became fainter during the course of the training phases. The better posttraining performance in heartbeat perception of the group receiving full-intensity feedback was also reflected in the evoked potentials. They differed markedly before and after training, especially between 250 to 400 ms (after the EKG-R-wave), the biggest effect being at Fz and F7. The findings are interpreted as the brain electrical reflection of an increased perception susceptibility to a cardiovascular signal occurring at about 200 ms after the R-wave.

Heartbeat perception and the right hemisphere: What is lateralized

Heartbeat perception and the right hemisphere: What is lateralized

The influence of self-focused attention on heartbeat perception.

ABSTRACTThe present study investigated the effect of a self‐attention enhancing manipulation on heartbeat perception in 22 females using a within‐subject design. Self‐attention was enhanced by placing a mirror in front of the subjects. Heartbeat perception was assessed using both heartbeat discrimination and heartbeat tracking procedures. It was found that subjects performed heartbeat discrimination more accurately when facing a mirror but heartbeat tracking performance was not affected by the same manipulation. The possible reasons for these conflicting results are discussed.

Cardiovascular asymmetries and cardiac perception.

Two strategies for evaluating the lateral specificity of cardiac sensory innervation were reviewed: (1) electrophysiological recording of cardiac-relevant cortical activity; and (2) behavioral assessment of right versus left differences in cardiac sensory perception. Electrophysiological data from two different laboratories suggest strongly that there is a link between cardiac events and cortical response to stimulation, but only for the right hemisphere. Two experiments from our laboratory suggest that there is a complex relationship among cerebral lateral preference, assessed by conjugate lateral eye movements, arousal, and individual differences in accuracy of self-perception of heart beats. The data, overall, suggest that the right hemisphere is involved specifically in heartbeat perception.

From the heart to the brain: a study of heartbeat contingent scalp potentials.

Heartbeat perception has become the most widely studied example of visceral perception. In the present study scalp potentials contingent to the visceral event "heartbeat" were investigated. Scalp potentials, averaged time-locked to the EKG-R-wave, were studied at Fz, Cz, and Pz under four conditions: resting (baseline), heartbeat discrimination task, signal detection task, and heartbeat discrimination task after physical exercise. 22 subjects were assigned to the two groups "good" and "poor" perceivers, according to their performance in an initial heartbeat perception test. Event related potentials (ERPs) of "good" perceivers were more stable across conditions than those of "poor" perceivers. Peak latency within the range of 200 to 300 ms differed significantly between conditions. A principal component analysis performed on the ERP averages extracted five components. Subsequent ANOVAs across factor scores yielded significant main effects for the "groups" factor, experimental conditions and electrode sites. The strongest effects occurred over the frontal region in the latency range of 250-400 ms (following the EKG-R-wave). These were found to be not due to artifactual EKG influences.

Blood, sweat, and tears: individual differences in autonomic self-perception.

ABSTRACTThis 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.

Laterality, Emotionality, and Heartbeat Perception

ABSTRACTRecent 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.

The effects of physical fitness and exercise on cardiac awareness

This experiment was run to further evaluate the role of individual difference factors in perception of heart beats (cardiac awareness). The present study examined 24 male subjects who showed high and moderate levels of physical fitness. Cardiac awareness was examined using Brener-Jones type discrimination trials. Subjects discriminated first while standing quietly on a treadmill (32 trials), then while walking briskly on a motorized treadmill (32 trials), and finally during recovery from exercise (elevated HR but behavioral quiescence) (16 trials). Results showed that only the moderate fitness group showed heightened awareness during exercise, while both groups showed greater than chance awareness during recovery from exercise. Neither group was highly aware while resting before exercise. These results fail to support notions that high fitness distance runners are highly aware of cardiac function during exercise. A number of reasons for this finding are discussed.

Heart beat perception and emotional experience.

ABSTRACTThe 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.

Perception of gastric contractions and self-control of gastric motility.

ABSTRACTThe 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.

Relation of heart rate control to heartbeat perception

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.

Cardiac perception and cardiac control

The evidence regarding specific cardiac perception and discrimination, and its relationship to voluntary cardiac control, is critically reviewed. Studies are considered in three sections, depending on the method used to assess cardiac perception: questionnaire assessment, discrimination procedures, and heartbeat tracking. The heartbeat tracking procedure would appear to suffer least from interpretative difficulties. Recommendations are made regarding the style of analysis used to assess heartbeat perception in such tracking tasks.