Cognitive task performance causes impaired maximum force production in human hand flexor muscles

Abstract: The purpose of this study was to investigate effects of demanding cognitive task performance on intermittent maximum voluntary muscle contraction (MVC) force production. Participants performed either a modified Stroop or control task for 22min. After the first min and at 3-min intervals thereafter, participants rated fatigue, perceived mental exertion and performed a 4-s MVC handgrip squeeze. A mixed ANOVA showed a significant interaction, F(7, 259)=2.43, p =.02, with a significant linear reduction in MVC force production over time in the cognitively depleting condition (p =.01) and no change for controls. Ratings of perceived mental exertion, F(7, 252)=2.39, p <.05, mirrored the force production results with a greater linear increase over time in the cognitive depletion condition (p <.001) compared to controls. Findings support current views that performance of cognitively demanding tasks diminishes central nervous system resources that govern self-regulation of physical tasks requiring maximal voluntary effort. [Copyright &y& Elsevier]