Induced discomfort promotes executive function while walking with(out) an artificial neuromuscular impairment

Abstract

Neuromotor disorders can degrade one's ability to locomote and attend to salient stimuli in the environment. Many disorders are physiologically complex, making it difficult to tease apart interactions between motor adaptation and executive function processes. We address this challenge by giving participants a controlled artificial impairment, using electrical stimulation to produce an uncomfortable disruption in normal muscular coordination during locomotion. While adapting to this gait perturbation, participants performed an executive function task containing neutral and affectively charged stimuli. The artificial impairment was counterbalanced against control and sham (discomfort-only stimulation) walking conditions. Our twofold hypothesis that discomfort would selectively tax hot, emotionally charged executive function and motor adaptation would challenge cold, logical executive function was not supported. However, we found that the discomfort experienced with both stimulation conditions improved participants' ability to inhibit distracting information, enhancing this aspect of executive function, and the effect did not depend on whether the task was affectively charged. Moderate discomfort during physical activity may have improved inhibitory control by increasing arousal, a known factor mediating executive function. These results show that using a sensorimotor perturbation that acts internally and bridges multiple physiological domains, including discomfort, can reveal effects not seen with purely environmental manipulations. The broader implications are that when high cognitive performance is needed during physical activity, it may be beneficial to, quite literally, operate outside one's comfort zone.NEW & NOTEWORTHY When locomotor and cognitive tasks compete for shared neural resources, cognitive-motor interference may impair performance in both domains. To understand how impairments that cause pain or change neuromotor control impact cognition during locomotion, we gave healthy adults an uncomfortable, artificial neuromuscular impairment while they walked and completed a task dependent on ignoring distracting stimuli. We found that discomfort enhanced participants' ability to ignore distractions, providing new insight into the mediators of cognition during impaired movement.

Keywords: artificial impairment; cognitive-motor interference; executive function; locomotion; motor adaptation.