Download Heartbeat detection and the experience of emotions

COGNITION AND EMOTION, 2000, 14 (3), 417± 427
Heartbeat detection and the experience of emotions
Stefan Wiens, Elizabeth S. Mezzacappa, and Edward S. Katkin
State University of New York at Stony Brook, USA
Although many theories of emotion hypothesise a crucial role for the selfperception 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 classi® ed as good (n 5 9) or poor (n 5 43) heartbeat detectors.
Subjects were then presented with sets of two ® lm 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.
Many psychophysiological theories of emotion hypothesise that selfperception of visceral activity is an important component of emotional
experience (Cacioppo, Berntson, & Klein, 1992; James, 1884; Schachter &
Singer, 1962). William James, for example, postulated that visceral activity is linked to emotional experience directly, proposing that ``our feelings
of the . . . changes as they occur IS the emotion’ ’ (1884, pp. 189± 190)
and, further, that it is upon the ``visceral and organic part . . . that the
chief part of the felt emotion depends’ ’ (1985, p. 250). Unlike James,
Schachter and Singer (1962) proposed that the unique quality, or valence,
of an emotional state is de® ned by cognitive labelling. Nevertheless,
Schachter and Singer agreed with James that visceral arousal must be
perceived to effect emotional experience (Reisenzein, 1983). Schachter
Requests for reprints should be sent to Edward S. Katkin, Department of Psychology, State
University of New York at Stony Brook, Stony Brook, NY 11794-2500, USA; email:
[email protected].
The authors are indebted to Anil Chacko, William Guethlein, Marc Lingat, and especially
Stephen Palmer for his invaluable assistance.
q 2000 Psychology Press Ltd
http://www.tandf.co.uk/journals/pp/02699931.html
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WIENS ET AL.
(1964) argued further that whereas the cognition determined the quality
of the emotion, the arousal determined the intensity of the emotional
experience so that ``emotionality is positively related to physiological arousal’ ’ (p. 65). If arousal is positively related to emotional experience, and if
the arousal must be perceived to determine the emotion, it may be inferred
from Schachter’s argument that individuals who are more sensitive to their
own visceral arousal should experience emotions more intensely than people who are less sensitive to their own viscera. Despite the importance of
visceral self-perception in psychophysiological theories of emotion, and the
® nding that individuals differ in the perception of their visceral activity (for
a review, see Katkin, 1985), there has been little empirical investigation
regarding the relationship between visceral self-perception and emotion.
Most attempts to evaluate individual differences in visceral selfperception have focused on the cardiovascular system, primarily because
heartbeats are discrete events that can be measured easily. Different tasks
have been developed to assess an individual’s ability to perceive his/her own
heartbeats. One approach has been to have subjects either count or tap in
synchrony with their heartbeats. Consistent with psychophysiological
theories of emotion, studies generally have found that people who perform
well on these tasks tend to be more emotional than those who do not
(Ludwick-Rosenthal & Neufeld, 1985; Montoya & Schandry, 1994;
Schandry, 1981). However, heartbeat detection tasks in which subjects
count or tap in synchrony with their heartbeat have several methodological problems (see Reed, Harver, & Katkin, 1990). For example, subjects who have some preconceptions about their heart rates may count or
tap at a rate that approximates that rate, even though they do not perceive
their heartbeats. That is, subjects may do well based on educated guesses
(Ring & Brener, 1996). Because of such methodological problems, the
validity of ® ndings obtained with heartbeat detection tasks in which
subjects count or tap in synchrony with their heartbeat is questionable.
Heartbeat detection tasks have been developed that overcome these
methodological de® ciencies (Brener, Liu, & Ring, 1993; Katkin, 1985;
Whitehead, Drescher, Heiman, & Blackwell, 1977; Yates, Jones, Marie, &
Hogben, 1985). In these tasks, subjects are required to discriminate
whether trains of external stimuli (e.g., tones) that are presented at varying
delay intervals from their heartbeats appear to be simultaneous with their
heartbeats. As the tones are all triggered by the subjects’ heartbeats, they
all follow the same rate and rhythm as the heartbeats, and differ only in
their temporal relationship to the heartbeats. Thus, only subjects who are
able to perceive their heartbeats are able to distinguish among the
delay intervals. These tasks have been shown to be reliable and valid
(Brener et al., 1993; Ferguson, Fernquist, Harver, & Katkin, 1989;
Katkin, 1985; Katkin, Blascovich, & Goldband, 1981; Katkin, Morell,
HEARTBEAT DETECTION AND EMOTION
419
Goldband, Bernstein, & Wise, 1982; Schneider, Ring, & Katkin, 1998).
Although there is some evidence that good heartbeat detectors, as assessed
by these tasks, report experiencing emotions more intensely than poor
detectors, the evidence is not consistent. For instance, Hantas, Katkin,
and Blascovich (1982), using only negative slide stimuli geared to the
experience of disgust, found that good heartbeat detectors reported that
they were more ``affected’ ’ by the slides than poor detectors. Eichler,
Katkin, Blascovich, and Kelsey (1987), using the same basic methods as
Hantas et al. (1982), were unable to replicate the ® ndings and found a
tendency toward poor heartbeat detectors being more ``affected’ ’ by the
slides than good detectors. Ferguson and Katkin (1996), using positive,
negative, and neutral slide stimuli, found that good heartbeat detectors
showed greater frequency, intensity, and duration of affect-appropriate
facial expressions than poor heartbeat detectors, but they did not ® nd a
parallel difference in self-report of affect. Further, Montgomery and Jones
(1984) found no relationship between heartbeat detection and questionnaire measures of anxiety and neuroticism, but Blascovich et al. (1992)
obtained a negative relationship between heartbeat detection and a questionnaire measure of affect intensity.
The present study was designed to examine further the relationship
between self-report of emotional experience and individual differences in
visceral self-perception. We used well-validated ® lm clips (Gross & Levenson,
1995) that have been demonstrated to elicit anger, fear, and amusement,
combined with the assessment of valence and intensity of self-reported
emotional responses and reliable and valid assessment of both visceral
self-perception and sympathetic nervous system arousal. The decision to
use anger, fear, and amusement was based on the desire to examine the
relation between heartbeat detection and emotions that are related to
sympathetic nervous system ® ght or ¯ ight responses (anger and fear), as
well as to examine the relationship between heartbeat detection and the
response to amusing stimuli, as amusement was one of the emotions
examined in the classic experiment of Schachter and Singer (1962) on
the relationship between arousal induction and emotion. Heart rate,
which is largely under parasympathetic regulation, was not assessed during the ® lm presentations, because it is not a particularly good measure of
sympathetic arousal (Kelsey, 1991; Mezzacappa, Kelsey, & Katkin, 1999).
Instead, sympathetic activity was assessed by the measurement of spontaneous skin conductance responses, a reliable and unobtrusive measure of
peripheral sympathetic arousal (Hugdahl, 1995; Katkin, 1975) that is
correlated with sympathetic in¯ uence on the heart (Kelsey, 1991).
Consistent with Schachter’s (1964) suggestion that arousal determines
the intensity, but not the quality of the emotion, we predicted that good
heartbeat detectors would report greater intensity of emotions to the ® lms
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than poor detectors, although it was not expected that good and poor
detectors would differ in valence ratings.
METHOD
Subjects
Fifty-two undergraduates (33 females, 19 males) participated; their ages
ranged from 18 to 41 (M 5 21.8, SD 5 5.1). All subjects received credit
toward a course requirement for their participation.
Apparatus
Skin conductance responses were detected by a pair of Ag-AgC1 electrodes
attached to the hypothenar eminence of a subject’s nondominant palm,
using a .05M NaC1 contact medium (Fowles et al., 1981). The skin
conductance signals were processed by a constant voltage circuit described
by Lykken and Venables (1971). The electrocardiogram (ECG) was
obtained using three stainless steel plate electrodes attached to the right
arm and both legs in Standard Lead II con® guration. Physiological signals
were fed through a Grass Model 7 polygraph. Skin conductance was
recorded on paper; the ECG was processed by computer software to
detect R-waves, which indicate the peak of ventricular depolarisation.
The ECG data were digitised and stored on disk. A Wavetech Model
182A 4 MHz function generator was used to generate 50 ms square-wave
tones at 800 Hz.
Procedure
The experiment was run in a single session and consisted of two parts. In
one part of the experiment, subjects performed a heartbeat detection task;
in the other part, subjects reported their affective responses to ® lm clips.
Task order was randomised; 30 subjects (57.7%) received the heartbeat
detection task ® rst, followed by the ® lm rating task, while the remaining
22 subjects (42.3%) rated the ® lms ® rst, and then took the heartbeat
detection task. The order of presentation of the three sets of ® lm clips
was also randomised across subjects. Electrodes were attached at the
beginning of the experiment. Skin conductance was recorded during each
® lm clip and for a 1 min rest period prior to the heartbeat detection task.
The ECG was recorded during the 1 min rest period and for each trial of
the heartbeat detection task.
HEARTBEAT DETECTION AND EMOTION
421
Heartbeat detection task. Forty trials were administered. Each trial
consisted of tones presented to subjects contingent on 10 successive heartbeats. The 10 tones within each trial were presented at a ® xed delay interval of
either 200 or 500 ms after the R-waves (Eichler & Katkin, 1994). The order of
trials was randomly determined with the restriction that there were 10 trials
at each interval within a block of 20 trials. Subjects were instructed to make
a forced-choice response after each trial, indicating on a button box whether
or not they believed the tones had been delayed from their heartbeats.
Film clips. Six ® lm clips ranging in length from 100 to 246 s were
presented to subjects. There were three sets of two ® lm clips each. The
® lm clips consisted of scenes that were found previously to elicit anger, fear,
or amusement (Gross & Levenson, 1995). The anger ® lms were scenes of:
(a) the slaughter of an unarmed civilian crowd by armed soldiers; and (b) a
high school bully beating up another student. The fear ® lms were scenes of:
(a) an unarmed soldier in the Vietnamese jungle, hiding from the encroaching enemy; and (b) a frightened female law enforcement of® cer searching
for a dangerous, homicidal criminal in a dark basement. The amusement
® lms were scenes of: (a) a humorous dialogue between an attractive man
and woman, containing overtly sexual content; and (b) a popular comedian’s monologue, with many drug-related anecdotes. After the presentation of each ® lm clip, subjects rated on 9-point scales how intense
(extremely mild to extremely intense) and how pleasant (extremely unpleasant to extremely pleasant) the ® lms made them feel.
Data reduction
Heartbeat detection task. Prior research has indicated that subjects
perceive tones at intervals between 200 and 300 ms from the R-waves as
simultaneous with their heartbeats, whereas tones at an interval of 500 ms are
rarely, if ever, perceived as simultaneous with their heartbeats (see Brener &
Ring, 1995). Based on this research, responses were coded as correct if
subjects indicated that tones that were presented 500 ms after their R-waves
were delayed from their heartbeats and that tones that were presented 200 ms
after their R-waves were not delayed from their heartbeats. Using the binomial distribution it was determined that the cumulative probability for correct
responses on 26 or more of the 40 trials was .04. Accordingly, subjects were
designated as good detectors if they had at least 26 correct responses and as
poor detectors if they had 25 or fewer correct responses. In this manner, nine
subjects (17.3%) were designated as good heartbeat detectors and 43 subjects were designated as poor heartbeat detectors. The proportions of good
detectors were similar for males (15.8%) and females (18.2%), c 2(1) < 1.
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WIENS ET AL.
Physiological measures. The number of spontaneous skin conductance
responses that exceeded an amplitude of 0.1 m s served as a measure of
sympathetic arousal (Katkin, 1965, 1975; Katkin & Hastrup, 1982). The
mean number of responses per minute were calculated for each ® lm pair
and for the rest period prior to the heartbeat detection task. Mean heart
rate was calculated for the rest period and across all trials of the heartbeat
detection task.
RESULTS
Emotion Ratings
Intensity ratings. Mean intensity ratings to the three pairs of ® lms for
good and poor heartbeat detectors are shown in Figure 1, which indicates
that good detectors reported experiencing greater intensity of emotion
than poor detectors across all three ® lm types. An ANOVA of intensity
Figure 1. Mean intensity ratings of good and poor heartbeat detectors (HBD) to pairs of
® lms targeting amusement, anger, and fear.
HEARTBEAT DETECTION AND EMOTION
423
ratings with heartbeat detection (good, poor) as a between-subjects variable and ® lm type (amusement, anger, fear) as a within-subjects variable
yielded only a signi® cant main effect of heartbeat detection, F(1, 50) 5 7.61,
p < .01.
Pleasantness ratings. In order to check that the ® lms elicited the
intended emotional valence, the mean pleasantness ratings to the three
pairs of ® lms (amusement, anger, fear) were evaluated across subjects. As
illustrated in Figure 2, the amusement ® lms elicited positive evaluations,
the anger ® lms elicited negative evaluations, and the fear ® lms elicited
small negative evaluations. An ANOVA of pleasantness ratings with heartbeat detection (good, poor) as a between-subjects variable and ® lm type
(amusement, anger, fear) as a within-subjects variable yielded a signi® cant
main effect of ® lm type, F(2, 100) 5 91.01, p < .0005. In addition, all paired
t-tests among the ® lm types showed signi® cant differences (ps < .001).
Figure 2. Mean pleasantness ratings of good and poor heartbeat detectors (HBD) to pairs of
® lms targeting amusement, anger, and fear.
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WIENS ET AL.
As further shown in Figure 2, good and poor heartbeat detectors did not
differ in their pleasantness ratings. In the ANOVA of pleasantness ratings
between heartbeat detection and ® lm type, there was no main effect for
heartbeat detection, F < 1, and no interaction with ® lm type, F(2, 100) 5
1.73. Follow-up t-tests also found no signi® cant differences between heartbeat detection groups in pleasantness ratings for any of the ® lm types.
Results of research on heartbeat detection have been reported traditionally in terms of dichotomous categorisation of groups of good and poor
detectors. However, heartbeat detection may well be conceptualised as a
continuous dimension. Therefore, in addition to the analysis of good and
poor detector groups described earlier, we also used a hierarchical multiple
regression analysis to evaluate the relationship between intensity ratings
and number of correct responses in the heartbeat detection task, controlling for task order, gender, sympathetic arousal, and pleasantness ratings.
In the ® rst step of the analysis, task order, gender, sympathetic arousal, and
pleasantness ratings to the three pairs of ® lm types were entered sequentially in predicting heartbeat detection; in the second step, the intensity
ratings to the ® lms were entered as a set. Neither task order (R2 5 0.00),
nor gender (R2 5 .05), nor sympathetic arousal (R2 5 .09), nor pleasantness ratings (R2 5 .11) alone or taken together accounted for a signi® cant
proportion of the variance. However, intensity ratings did explain a signi® cant proportion of variance (change in R 2 5 .17, p < .02), controlling
for the other variables. These ® ndings con® rm that the relationship
between heartbeat detection and self-reported intensity of emotional
experience was independent of task order, gender, arousal level, and pleasantness ratings, and indicate further that the relationship between heartbeat detection and intensity ratings was signi® cant, whether heartbeat
detection was analysed dichotomously or continuously.
Physiological measures
Heart rate. There were no signi® cant differences between good and
poor heartbeat detectors in heart rates at rest or during the heartbeat
detection task.
Skin conductance. Good and poor heartbeat detectors did not differ in
electrodermal activity at rest. Although there were also no group differences in electrodermal activity across ® lms, good detectors tended to show
more electrodermal activity than poor detectors during the amusement
® lms only. An ANOVA yielded no main effect for heartbeat detection,
but a signi® cant Heartbeat Detection 3 Film Type interaction, F(2, 94)
5 3.24, p < .05. However, follow-up t-tests for each ® lm type indicated that
HEARTBEAT DETECTION AND EMOTION
425
none of the differences between good and poor perceivers was signi® cant.
Subsequent analyses of emotion ratings were run without and with electrodermal activity as a varying covariate to control for sympathetic activity in
response to each ® lm type. The ® ndings were the same either way; therefore, the results of the simple analyses of emotional ratings without
electrodermal activity as a covariate were reported.
DISCUSSION
The ® ndings of this experiment are consistent with the hypothesis that
heartbeat detection as an index of self-perception of visceral activity is
associated with intensity of emotional experience but not with valence.
More speci® cally, good heartbeat detectors reported experiencing emotions more intensely than did poor detectors in response to ® lm clips
chosen to elicit a range of emotions. These results provide support for
those psychophysiological theories of emotion (Cacioppo et al., 1992;
James, 1884; Schachter & Singer, 1962) which state that perceived visceral
activity affects experienced emotion.
An important assumption is that visceral self-perception is independent
of sympathetic arousal. That is, good and poor heartbeat detectors should
not differ in their arousal level. Otherwise it would be impossible to
determine if good heartbeat detectors show more intense emotions than
poor detectors because of greater arousal or because of more accurate selfperception of their visceral activity. Data from the present experiment
indicate that there were no differences between good and poor heartbeat
detectors in heart rate and small statistically nonsigni® cant differences in
rate of skin conductance responses, an index of sympathetic nervous
system activity. Previous research has also supported the idea that heartbeat detection and visceral activity are unrelated (Ferguson & Katkin,
1996; Hantas et al., 1982; Schandry, 1981). Nevertheless, a more representative sample of physiological measures in combination with a larger
sample size would be necessary in future studies to increase con® dence
in the conclusion that the relationship between visceral self-perception and
emotional intensity is not confounded by visceral activity.
Finally, these results cannot of themselves demonstrate a causal relationship between heartbeat detection and emotional intensity, as they are
correlational in nature. One cannot rule out the possibility that some as yet
unidenti® ed third factor is causally related to both increased intensity of
emotional experience and increase in accuracy of visceral self-perception.
Yet, these data do seem consistent with the oft reported lack of relationship
between autonomic and experiential aspects of emotion. Our data indicate
that subjects who are good heartbeat detectors report more intense emotion than poor heartbeat detectors, even though they show no differences
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in sympathetic arousal. It is possible that the ``decoupling’ ’ of self-report
and arousal level re¯ ects individual differences in sensitivity to the arousal
level. Future studies should be addressed to determining if there is a causal
link between visceral self-perception and emotional experience. One possible approach would be to directly manipulate heartbeat detection ability,
for example through feedback training (see Katkin et al., 1981), and
observing its effect on emotions.
Manuscript received 28 April 1999
Revised manuscript received 27 September 1999
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