TEMPORAL AND ACROSS-TASK STABILITY OF CARDIOVASCULAR-RESPONSE PATTERNS DURING PSYCHOLOGICAL AND PHYSICAL CHALLENGE

An attempt was made to examine temporal stability and intertask consis tency of both individual measures and response patterns identified by a multivariate clustering procedure. Seventy-two normotensive students (36 males and 36 females) aged 18-28 years were exposed to three labo ratory stressors (mental arithmetic, speech preparation, bicycle ergom eter) in two sessions scheduled four weeks apart. Recordings of heart rate, and systolic and diastolic blood pressure were obtained during p re-task rest periods and task performance. ANOVAs with repeated measur es revealed significant task-specific effects. Moreover, by utilizing Ward's clustering procedure which was performed on the mean reactivity values (delta change) for psychological. challenge (mental arithmetic and speech preparation combined) and exercise, three different respon se clusters could be identified for each type of challenge. As expecte d, retest correlations for absolute values were consistently higher th an those for reactivity scores. However, results of multivariate analy ses of variance provided only limited support for temporal stability o f response patterns. Analyses of inter-task correlations suggest a gre ater extent of generalizibility for heart rate and blood pressure resp onses across psychological stressors than across psychologically and p hysically demanding tasks. There was no evidence of inter-task consist ency for response patterns across psychological and physical challenge s.