Explicit achievement motive strength determines effort-related myocardial beta-adrenergic activity if task difficulty is unclear but not if task difficulty is clear

Work on physiological and other behavioral correlates of motives often assumes that exert a direct effect behavior once activated. Motivational intensity theory, however, suggests this does not always apply. In the context task engagement, motive strength should myocardial beta-adrenergic activity if difficulty is unclear, but known. The presented study tested prediction for impact explicit achievement activity—assessed as pre-ejection period (PEP) reactivity during performance. Seventy-eight participants performed one two versions mental arithmetic task. After having completed scale Personality Research Form, were either informed about or before working it. Participants' PEP performance provided evidence predicted moderating clarity difficulty: increased with increasing was it clear. These findings demonstrate moderated by suggest translate into effects physiology behavior.