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Biomedical subjects

M H Pollak

Publications and source records attributed to M H Pollak.

6 recordsLinked to original sources
PubMed1980

Bidirectional changes in digital skin temperature using biofeedback in a cold room.

The ability to increase digital skin temperature (DST) of cold extremities or to prevent decreases in DST in a cold environment may be useful clinically in the treatment of Raynaud's disease or in the alleviation of the effects of stressful stimuli. Ten Ss, each of whom participated in five sessions, were studied in a room at 20 degrees C. Each session was divided into 5-minute trials during which Ss either received auditory biofeedback of DST and tried to increase or decrease DST or received no feedback and merely sat quietly (Baseline trials). There were significant changes in DST during Baseline trials; these changes were different at different times during the session. The difference between Increase and Decrease trials was significant. The DST decrease during Decrease trials was significantly different from the change during corresponding Baseline trials, while the Increase trials, while the Increase trial DST, although of the same magnitude as the decrease trial, did not differ significantly from its corresponding Baseline trials DST.

Biofeedback, Psychology↗
PubMedDate not supplied

Heart rate reactivity to laboratory tasks and ambulatory heart rate in daily life.

This study investigated relationships between laboratory task-related heart rate reactivity and ambulatory heart rate responses and variability during daily life. Sixty-two healthy, young men completed one laboratory session consisting of pretask rest, reaction time, video game, and mental arithmetic, and one 24-hour ambulatory heart rate monitoring day. After controlling for ambulatory physical activity, laboratory reactivity measured as basal-to-task increase correlated significantly with ambulatory minimum, mean, and maximum increases from basal during wakefulness and with awake mean square successive difference. After controlling for ambulatory physical activity, laboratory reactivity measured as pretask-to-task increase correlated significantly only with awake mean square successive difference. These results support the hypothesis that individual differences in heart rate responses to laboratory tasks reflect similar differences in heart rate responses and variability during daily life. Results are compared in their degree of support for two theoretical models describing the generalization of individual differences in laboratory reactivity to reactivity during daily life.

Adolescent↗
PubMedDate not supplied

Heart rate reactivity to laboratory tasks and in two daily life settings.

This study investigated relationships between laboratory task-related heart rate reactivity and heart rate responses in two daily life settings. The main purpose of the study was to demonstrate that the expression of heart rate reactivity during daily life depends on the nature of the daily life situation, or on subjective or behavioral responses in the daily life situation. Twenty-six healthy, male medical students completed one laboratory session consisting of pretask rest, reaction time, video game, and mental arithmetic conditions, and 2 day-long field study periods, during which subjects either worked as student physicians in a medical clinic or attended classroom lectures. After controlling for differences in daily life physical activity levels, (1) heart rate levels were significantly higher during clinic work periods, compared to classroom work periods and evenings of both days, (2) and heart rate responses to the tasks correlated significantly with minimum, mean, and maximum heart rate responses from the clinic work period, but not from the other field periods. Thus, individual differences in heart rate reactivity were found in one daily life situation, but not in another daily life situation. These results support the experimental hypothesis.

Adult↗