Psychophysiological response patterns to single, double, and triple stressors.

Synergistic activation elicited by multiple stressors as compared to single stressors has received little attention in the literature. In the present study, mental arithmetic, cold pressor, and physical exercise tasks were administered to 54 male subjects alone and in all possible simultaneous combinations. The dependent variables measured were heart rate, cardiac output, RZ-time, blood pressure, respiration rate, tidal volume, respiratory minute volume, oxygen uptake, oxygen equivalent, self-report data of psychological and somatic tension, pain ratings during the cold pressor test, and performance on mental arithmetic. Results for physiological variables indicate synergistic effects for stressor combinations as compared to single stressors, depending on the respective combination or variable. Contrary to this finding, psychological variables revealed ceiling and depressor effects. Response patterns to the different stressors showed only moderate similarity and exhibited stimulus-specific effects. Heart rate, diastolic blood pressure, and respiration rate were most appropriate in describing various response patterns.