Cardiovascular responses, performance, and mood in heart rate reactive individuals during a challenging cognitive task

Abstract

Subjects ( n=24) were classified as either high or low in heart rate reactivity using a mental arithmetic task. They then performed computer versions of a challenging cognitive task, the Stroop Color-Word Interference Test. Subjects completed a congruent version of the Stroop task, and a more demanding incongruent version. Measures included heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), performance at the tasks in terms of speed and accuracy, and self reports of anxiety, depression and hostility. In comparison to the congruent task, the incongruent Stroop task elicited larger HR responses, as well as higher SBP and DBP levels among subjects of both reactivity groups. Furthermore, the incongruent task was associated with a cluster of negative emotional responses as reflected in the self-reports of heightened anxiety, depression, and hostility. Results indicated that the two reactivity groups differed in their cardiovascular and behavioral responses to the tasks. Although there was no difference between groups during the incongruent Stroop task, only the highly reactive subjects showed HR increases during the easy, congruent task. These subjects also showed more labile SBP fluctuations across conditions, whereas variations in DBP were not affected by HR reactivity. Performance results revealed that highly reactive subjects coped with the incongruent task by adopting a slower pace than low HR reactive subjects. There were no significant differences between groups for trait and state measures of anxiety, depression and hostility.