Task difficulty, cardiovascular response, and the magnitude of goal valence

Sixty-four young women expected to perform an easy, moderately difficult, or extremely difficult memory task with the opportunity to earn a small incentive for good performance. Cardiovascular (heart rate, systolic and diastolic blood pressure) and subjective measures were taken immediately prior to task performance. Both systolic blood pressure (SBP) responses and ratings of goal attractiveness were nonmonotonically related to expected task difficulty, with the most pronounced SBP elevations and highest goal attractiveness in the moderately difficult task condition. Product-moment correlations among cardiovascular response measures revealed a strong positive association between systolic and diastolic pressure (but not heart rate) change in the easy condition, positive relationships among all measures in the moderately difficult condition, and no significant correlations in the extremely difficult condition. Subjective measures of arousal were not affected by the task difficulty manipulation. Principal findings are discussed in terms of a theoretical model proposed by Brehm (1979) that states that motivation varies as a nonmonotonic function of the difficulty of goal attainment. Intercorrelations among cardiovascular response variables are considered in terms of their possible indication of the mechanisms underlying blood pressure changes associated with variations in motivation.