Pavlos Anastasiades

The psychophysiological responses to laboratory stressors are often examined because it is believed that such responses relate to responsiveness in real life situations. This belief has seldom been tested. The changes in heart rate, pulse transit time, and respiration rate produced by a variety of laboratory tasks (active and passive coping and physical exercise) were related to ambulatory measures of heart rate in 32 young men. The field measures were the difference in heart rate between the waking day and when asleep, and estimates of the variability of heart rate during the day, derived from time series analyses. Average changes in heart rate and pulse transit time during specific tasks did not relate consistently to heart rate in the field. However, an active coping index, derived from the ratio of the peak heart rate during an active coping task to the peak during physical exercise related to all the field measures of heart rate responsiveness. This index, which may relate to measures of additional heart rate and heightened sympathetic response to stress, also correlated positively with Trait Anxiety and elevated basal sympathetic arousal, as measured by skin conductance level. Measures of the cardiovascular response to a passive coping task, the cold pressor, and exercise did not relate to heart rate responses in the field. The findings suggest that heightened cardiac responsiveness in real life is exhibited by subjects who show elevated peak responses to active coping stressors specifically.

Panic attacks are one of the most distressing of all forms of anxiety. The sudden onset of attacks and the intense bodily sensations which accompany them often lead patients to think they are about to die, go crazy, or suffer some other catastrophe. The fact that some attacks also appear to occur without warning is additionally alarming to patients and was initially interpreted by research workers as an indication that the central disorder in panic is a neurochemical disturbance. This point of view received further support from work on the pharmacological induction and treatment of panic. However, a number of investigators (Barlow, in press; Beck et al. 1985; Clark 1979, 1986; Griez and van den Hout 1984; Margraf et al. 1986; Rapee 1987, Seligman 1988) have recently proposed psychological theories which can also account for the main features of panic. In the present paper we provide a brief overview of one of the these theories — the cognitive theory described by Clark (1986) — and describe a series of experiments testing central predictions derived from this theory. Readers who would like a more detailed exposition of the theory are referred to Clark (1986, 1988) and Salkovskis (1988).

A randomized trial in general practice compared: (i) a brief psychological treatment (problem-solving) given by a psychiatrist; (ii) any treatment of the GP's choice, whether psychological or pharmacological. The patients had recent onset emotional disorders of poor prognosis. Patients in the problem-solving group showed significantly greater reductions in symptoms. Problem-solving as given by a psychiatrist was feasible in primary care and acceptable to patients. Problem-solving is now being evaluated as given by general practitioners trained in the method.

The Laceys' account of the significance of heart rate changes for behaviour is critically evaluated. Two interwoven propositions are discerned in their account: first, the cardiac variations regulate central attentional activities via an afferent feedback mechanism; second, that environmental intake-rejection comprises a basic dimension underlying directional cardiac changes. Examination of pertinent psychophysiological research reveals that the first of these propositions lacks substantive support. The intra-cardiac cycle method has yielded highly equivocal results. Inter-cardiac cycle studies offer only modest correlational support and the two studies which have directly manipulated heart rate found that sensori-motor performance was largely unaffected. Difficulties also surround the other proposition. Consideration of the verbalization, pleasantness-unpleasantness and time estimation studies indicates that the relationship between heart rate and attention is variable and that heart rate is associated with factors other than attentional requirements. While the Laceys have attempted to reconcile such unfavourable evidence, conceptual clarity is frequently sacrificed in the process. It is concluded that the interpretation of cardiac responses must be sought in superordinate variables that account for both heart rate changes that can be related to attention and those that cannot, and that any afferent feedback mechanism, based on heart rate, most likely fulfills functions other than that proposed by the Laceys.

A simple activity measure based on the EMG recorded from the thigh was developed to monitor the physical activity of ambulatory subjects. The performance of this activity measure was assessed during four major physical activities: running, walking, standing, and sitting. Heart rate was also monitored. The results were analysed within individuals using time series analysis. The heart rate and activity series (of consecutive 30-s means) required similar models within individuals, and both measures differentiated among running, walking, and non-movement. The activity measure did not discriminate between postures. This measure covaried closely with heart rate and emerged as a necessary and relatively more significant predictor of heart rate variance than knowledge of the type of physical activity the subjects were undertaking. Posture, however, did add a significant and independent contribution to heart rate variance. This activity measure appears to be a simple, reliable, and valuable method of measurement of physical activity variations in ambulatory subjects.

The psychophysiological responses to laboratory stressors are often examined because it is believed that such responses relate to responsiveness in real life situations. This belief has seldom been tested. The changes in heart rate, pulse transit time, and respiration rate produced by a variety of laboratory tasks (active and passive coping and physical exercise) were related to ambulatory measures of heart rate in 32 young men. The field measures were the difference in heart rate between the waking day and when asleep, and estimates of the variability of heart rate during the day, derived from time series analyses. Average changes in heart rate and pulse transit time during specific tasks did not relate consistently to heart rate in the field. However, an active coping index, derived from the ratio of the peak heart rate during an active coping task to the peak during physical exercise related to all the field measures of heart rate responsiveness. This index, which may relate to measures of additional heart rate and heightened sympathetic response to stress, also correlated positively with Trait Anxiety and elevated basal sympathetic arousal, as measured by skin conductance level. Measures of the cardiovascular response to a passive coping task, the cold pressor, and exercise did not relate to heart rate responses in the field. The findings suggest that heightened cardiac responsiveness in real life is exhibited by subjects who show elevated peak responses to active coping stressors specifically.