Mechanisms Underlying the Learning of Skilled Movement Execution via Motor Imagery

Abstract

Learning to move skillfully is a fundamental behaviour. Motor skills can be learned even in the absence of overt bodily movement through a process known as motor imagery — the mental rehearsal of movement — which has promising applications in rehabilitation. However, the mechanisms underlying imagery-based motor learning are not well understood and learning may be attributed to improvements in perceptual or cognitive processes rather than improvement in movement execution itself. The research projects presented in this dissertation aimed to investigate whether motor imagery is capable of driving improvements in movement execution and if so, what the underlying mechanisms of this might be and how they differ from that of overt practice. Using a novel experimental task designed to answer this question, the findings presented here suggest that motor imagery is indeed capable of driving the learning of skilled movement execution, though of a lesser magnitude than overt practice. In the absence of sensory feedback, motor imagery appears capable of determining the accuracy of an imagined movement. Neuroimaging results demonstrated that imagined movement accuracy was associated with similar brain regions as overt movement accuracy but with substantially different activation patterns. Together these results suggest that motor imagery appears to afford one with a prediction of the motor and sensory consequences of an imagined movement such that a comparison can be made with intended consequences, which provides a basis for improving subsequent movement attempts, imagined or otherwise. These results highlight the importance of minding experimental design when studying motor imagery and validating its utility for clinical applications.