Activation of the arousal response can impair performance on a simple motor task

The purpose of this study was to determine the effect of arousal in men and women on the moment-to-moment performance of a simple motor task. We exami ned the control of a precision task in the presence and absence of imposed stressors. Twenty-nine subjects (14 men, 15 women; 18-44 yr) were randomly assigned to either a control group or one of two stressor groups, Mental Ma th or Electric Shock. Subjects presented with Math and Shock stressors, whi ch lasted 10 min, experienced significant increases in cognitive and physio logical arousal compared with baseline and control subjects. Heart rate, sy stolic blood pressure, and electrodermal activity were elevated 5-80% with presentation of the stressors, whereas diastolic blood pressure and salivar y cortisol were unchanged. The greater levels of cognitive and physiologica l arousal were associated with reductions in steadiness of a pinch grip for the Shock subjects (similar to 130% reduction from baseline) but not for t he subjects in the Math group, who experienced heightened arousal but no ch ange in steadiness (10% reduction from baseline). Although women exhibited more of a reduction in steadiness than men, the effect was largely unrelate d to the magnitude of the change in arousal.