Anticipatory and residual effects of an active coping task on pre- and post-stress baselines.

This study examined several issues concerning baseline measurement in cardiovascular reactivity testing: effects of anticipation of stress on baseline, point at which initial baseline stabilizes, effects of a stressful task on a succeeding baseline, and gender differences in baseline patterns. Ten males and ten females sat for a 30-min initial baseline period, a 2-min stressor (mental arithmetic), and a 15-min post-stress period. An additional ten males and ten females participated only in the 30-min initial baseline (no stressor). There was no difference in initial baseline between the stress and no-stress conditions; nor were there interactions between this factor and gender. Initial baseline stabilized at resting levels after approximately one minute. Post-stress rest levels were significantly higher than initial baseline levels for blood pressure (5.8 and 4.8 mmHg for systolic and diastolic pressure, respectively), but not for heart rate. Implications of recovery of baseline are discussed.