Task-induced cardiovascular activity and the presence of a supportive or undermining other

In order to examine the effects of positive and negative social interaction on task-induced cardiovascular activity, 90 undergraduates were allocated to one of three conditions: alone; with a confederate who offered support of subjects' judgements; with a confederate who disagreed with subject' judgements. In each of the 16 problem trials of the task, subjects had to indicate which of a series of cubist paintings was painted by the same artist as a target painting. Confederates were represented as possessing expert knowledge. Confederates offering positive support explicitly confirmed subjects' answers on 14 of the 16 problems and made other supportive comments; disagreeing confederates gave different answers to the subjects on 14 of the 16 problems and made other dismissive comments. Systolic and diastolic blood pressure, and heart rate, were monitored at pre-task baseline, and during the task. Average task values were compared across conditions using ANCOVA, with baseline as the covariate. A significant effect of conditions emerged for heart rate; the negative, undermining condition provoked higher HR than the alone condition. Subjects in the positive confederate condition reported more support than those with the negative confederate.