Cardiovascular Response to Stress: Effects of Opportunity to Avoid, Shock Experience, and Performance Feedback

ABSTRACT The cardiovascular effects of three factors related to active coping were examined during an unsignaled reaction time (RT) task involving exposure to mild shocks. These factors were the opportunity to avoid shocks contingent on performance, prior experience with the shock, and the availability of performance feedback. A yoked control design was used to ensure that shocks were delivered to avoidance and no‐avoidance subjects on the same schedule. All subjects initially showed substantial increases in systolic blood pressure (SBP) and both cardiac rate and performance, but these diminished later in the task. Subjects who could avoid shocks showed greater changes in SBP, heart rate (HR), and pulse transit time (PIT) than those passively exposed to shocks. Lack of prior experience with the shock augmented changes in HR, PTT and carotid dP/dt, but the HR increase was no longer reliable after the first 2 min when all subjects had experienced the shock. For subjects who could control the task by avoiding shocks, providing performance feedback had no effects. For no‐avoidance subjects, providing feedback led to changes in SBP and PTT which were significantly greater than those shown by the subjects without feedback. These findings are consistent with the hypothesis that characteristics which increase active coping efforts evoke greater sympathetically mediated cardiovascular changes.