Heart and Emotion

Chapter 4 Interoception (p. 53-55)

Interoception means the perception of bodily sensations such as hunger, thirst, tiredness, chest pain, palpitations of the heart, and so on. Some of these sensations are interpreted by the individual as indicating a disease which may lead one to search for medical advice. Other terms in this context are introspection (Mechanic & Hansell, 1987) and symptom awareness. There are individual differences in introspection resulting in different awareness and reports of bodily complaints. Several studies dealt with interoception, especially with the perception of heart rate. These studies are of theoretical interest because they can answer the question to what extent internal physiological processes can be perceived.

Symptom awareness has medical consequences as shown, for example, for the results of cardiac catheterization. About one quarter of all catheterizations show negative angiographic findings. On the other hand, one quarter of catheterizations are made too late with severe positive angiographic results. According to Frasure-Smith 1987), the latter group of patients has a low level of bodily awareness or has not complained enough about symptoms which would have led to an earlier angiography. Men with negative angiographic findings had a high level of bodily awareness whereas men with increasing positive findings had decreasing awareness.

Pennebaker (1982) has shown that bodily symptoms are perceived in the same way as external events. Because information processing is limited, external and internal sensory data compete for processing. The probability of reporting symptoms is inversely related to the quantity of external information at any given time and, therefore, dependent on the actual situational circumstances. A second important fact is that symptoms are interpreted within cognitive schemas or hypotheses available to the individual. According to such hypotheses, attention is directed selectively to that sensory information which supports the present hypothesis. In the opinion of Pennebaker, people are not able to perceive physiological states reliably because the interindividual and intraindividual correlations between symptoms and physiological states are typically low. Moreover, persons who perceive a special physiological state rather well, are not able to perceive another physiological state with the same accuracy. Finally, only changes but not the level of a physiological state are perceived.

4.1 Some findings from the literature.

Several experimental studies investigated the interoception of physiological functions, especially heart rate and blood pressure. The reason for these studies is the idea that interoception might be helpful to improve the therapy of physiological disorders such as hypertension, increased resistance in the respiratory tract, arrhythmias, etc. If it is basically possible to perceive physiological functions, it would offer the opportunity to increase interoception by adequate training.

In a study by Jones, Jones, Cunningham, and Caldwell (1985), the perception of heart rate in myocardial infarction patients as compared to healthy persons was investigated. No difference in interoception between the groups was found and interoception in both groups was low. A low level of interoception was also seen in students by Katkin, Morell, Goldband, Bernstein, and Wise (1982) and by Pennebaker and Hoover (1984). Schandry (1981) investigated the accuracy of heart rate perception and the degree of emotional lability in a group of healthy persons. Emotionally labile persons showed a better perception than emotionally stable persons. The author suggests that the higher anxiety level in emotionally labile persons might be a result of their better perception of physiological functions. On the other hand, it might be that emotionally labile persons have a higher awareness of bodily functions, thus being better trained in discriminative tasks assessing the accuracy of perception. Actually, it has been shown that heart rate perception can be trained to a certain degree (Katkin et al., 1982; Weitkunat, Schandry, Sparrer, & Beck, 1987).