The impact of thermal and auditory unpleasant stimulus on motor imagery in healthy individuals

Motor imagery is the ability to mentally simulate a motor task without actually performing it. Pain is an unpleasant sensory experience that involves different dimensions - sensory-discriminative, motivational-affective, and cognitive-evaluative - that are known to interfere with motor imagery. However, it remains unclear which specific pain dimension most significantly impairs motor imagery. This study aims to compare the effects of unpleasant auditory (primarily affective and cognitive) and thermal (primarily sensory) stimuli, which can be assimilated to pain, on discrete and continuous explicit motor imagery modalities. Eighteen healthy participants were exposed to unpleasant stimuli in addition to a control condition. Participants rated their motor imagery abilities after tasks involving rest, motor execution, and motor imagery in discrete and continuous wrist movement modalities. Results showed that during discrete motor imagery, only the aversive auditory stimulus significantly reduced motor imagery abilities, whereas thermal pain had no effect. In contrast, motor imagery abilities were preserved during the continuous modality. These findings suggest that explicit motor imagery may be more affected by the affective dimension of pain induced by aversive auditory stimuli. The preservation of motor imagery abilities in the continuous modality provides insight into the optimization of rehabilitation programs.