Difficulty as a determinant of cardiovascular response: moderating effect of instrumentality in an alleviation paradigm.

Female subjects performed 40 trials of an easy or difficult digit-recognition task while being exposed to intermittent presentations of a noxious noise. Half (high instrumentality) were told that, if they performed well, there was a high chance that they would work without noise in a subsequent trial period. The rest (low instrumentality) were told that, if they performed well, there was a low chance that they would work without noise in the subsequent trial period. Thus, a good performance insured either a high or low probability of alleviating the aversive stimulus. Results indicated that systolic responsiveness was proportional to task demand when the instrumentality of alleviative behavior was high, but low under both task conditions when the instrumentality of alleviative behavior was low. Reaction time and performance data were generally consistent with the view that these effects were due to group differences in task engagement, or 'active coping'. The main findings conceptually replicate and extend results from two previous studies that crossed difficulty and instrumentality manipulations. They also call further into question familiar theoretical conceptions that intimate direct effects of incentive value and perceived control on cardiovascular reactivity.