The role of motor expertise and physical fatigue in modulating the ability of action prediction

The notion that motor expertise drives the comprehension and prediction of others’ actions raises two pivotal questions. The first concerns whether motor expertise modulates differently the action prediction skills between individuals in which motor expertise is not only extremely specialized but also partially overlapped. The second explores whether physical fatigue influences these predictive abilities and, if so, how it impacts both motor and non-motor-mediated cognitive functions, such as action prediction and attentional control. Starting from these premises, this thesis first investigates the role of position-specific motor expertise in action prediction among rugby and soccer players. Findings demonstrate that players with specialized training in actions specific to their field positions – such as rugby goalkickers and soccer players trained in position-related skills – exhibit significantly higher accuracy in predicting the outcomes of those actions. This supports the hypothesis that action prediction proficiency exists along a continuum of motor expertise, where greater specificity in motor training leads to enhanced predictive accuracy for corresponding actions. In the second phase, we examine the effects of physical fatigue on action prediction using two distinct fatigue-induction protocols: cycle-ergometer exercise (i.e., systemic cardiopulmonary fatigue) and isometric handgrip exercises (i.e., limb-specific fatigue). The results indicate that fatigue impairs action prediction performance, specifically limiting the learning effect in the case of systemic disruption while preserving such an effect after a physical peripheric perturbation. These findings extend beyond sports, highlighting practical applications for occupational and rehabilitation settings where wearable assistive technologies, such as exoskeletons, could help mitigate motor-mediated cognitive disruption induced by physical fatigue. Overall, my Ph.D. thesis underscores that action prediction is closely tied to specialized motor expertise and is sensitive to the effects of fatigue. These insights open avenues for developing optimized training protocols, neurorehabilitation approaches, and ergonomic interventions aimed at enhancing cognitive and motor performance in diverse practical contexts.