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

Area of Science:

• Neuroscience
• Exercise Physiology
• Cognitive Psychology

Background:

• Cognitive fatigue is increasingly recognized as a factor influencing physical performance.
• The relationship between cognitive load and the central nervous system's capacity for self-regulation requires further investigation.

Purpose of the Study:

• To investigate the effects of demanding cognitive task performance on intermittent maximum voluntary muscle contraction (MVC) force production.
• To examine the impact of cognitive depletion on perceived exertion and fatigue.

Main Methods:

• Participants engaged in either a modified Stroop task (cognitive depletion) or a control task for 22 minutes.
• Maximum voluntary muscle contraction (MVC) handgrip force, fatigue, and perceived mental exertion were measured at regular intervals.

Main Results:

• A significant linear reduction in MVC force production over time was observed in the cognitive depletion group (p=.01).
• Perceived mental exertion increased linearly over time in the cognitive depletion group (p<.001), mirroring force production decline.
• No significant changes in MVC force were observed in the control group.

Conclusions:

• Cognitively demanding tasks diminish central nervous system resources available for self-regulation.
• Cognitive load directly impacts the ability to exert maximal voluntary physical effort.
• These findings highlight the interconnectedness of cognitive and physical self-regulatory mechanisms.