EFFECT OF PHYSICAL EXHAUSTION ON COGNITIVE-FUNCTIONING

Experiments utilizing reaction time to measure the effects of fatigue on cognition must discern sensitivity of peripheral and central proces sing to strenuous exercise. The additive factors method enables one to stipulate that if fatigue interacts with subjects' reaction time in a decision task, central processing is affected by fatigue. While pedal ing al different intensities, 13 physically-fit men had to perform a s eries of short-term memory rests. The tests were executed during a con stant workload session and a progressive workload session in which sub jects pedaled until exhaustion. Subjects provided ratings on Borg's 19 70 scale to measure the psychological effects of the physical effort s uch as perceived exertion. Allocation of processing resources was also measured to determine attentional constraints exerted by the dual-tas k situation. Analysis showed that decision reaction time was affected only during the exhausting bout of the progressive workload session an d for the more difficult decision task. We discuss our results in the context of arousal and the allocation of processing resources.