The effects of auditory consequences on visuomotor adaptation and motor memory

Humans have a remarkable ability to learn a wide range of motor behaviours and adapt them to different conditions. Motor learning involves rectifying movement errors and retaining corrected actions for future execution. Recent research indicates that experiencing balance-threatening physical consequences when making a movement error during adaptation can enhance motor memory. This is perhaps not surprising, as learning to avoid injury is critical for our survival and well-being. However, it remains unclear whether other forms of consequences can impact motor learning. The goal of this thesis is to determine if a non-physical consequence, a loud acoustic stimulus (LAS), can also improve motor learning, potentially through increased emotional arousal. Twenty-four participants adapted to a novel visuomotor mapping induced by prism lenses while performing a precision walking task that required them to walk and step to the center of a target projected on the ground. We randomly divided participants into two groups: an auditory consequence group and a control group. In the auditory consequence group (n = 12), participants received a LAS of 85 dB if they missed the target. Participants in the control group (n = 12) faced no consequences for a stepping error. Generalization was assessed through an interlimb transfer test (i.e., stepping to target with non-adapted foot) and obstacle-avoidance task (i.e., stepping laterally over an obstacle), both performed without prisms. The results demonstrated that the auditory consequence group exhibited greater generalization during the interlimb test, although this effect was less prominent in the obstacle-avoidance task. To evaluate consolidation, an opposite direction visuomotor mapping was introduced after initial adaptation in the first testing session and then performance with the initial mapping was re-tested one week later. Both groups showed reduced foot-placement errors during the second testing session, indicating successful consolidation. However, no significant differences were found between the groups. Overall, this thesis provides initial evidence that auditory consequences may enhance the generalization process but does little for consolidation. However, our findings suggest a connection between increased emotional arousal and improved generalization and savings. This implies that there may be potential in designing motor learning environments that enhance engagement and emotional arousal, which could be a valuable avenue for exploration, particularly in rehabilitation settings.