Neural plasticity as a basis for motor learning and neurorehabilitation

Skilled action is the end-product of learning processes that can improve several aspects of motor control such as strategic movement organisation, perceptual-motor associations, or muscle commands for basic components of sequentially evolving, complex movements. Experimental studies in healthy participants using functional imaging and transcranial magnetic stimulation have identified separable processes that form cortical motor representations and that assist this formation of representations. These processes capitalise on usedependent plasticity and changes in cortical excitability before and after practice. In terms of neural circuits, motor learning manifests measurably via structures that support transient phenomena, such as attentive error monitoring, or through continued activation of brain structures that support control processes still adapting. Specifically, movement guidance engages the dorsal premotor and parietal cortex along the intraparietal sulcus in addition to the supplementary motor area and the anterior cerebellum. Movement conception based on explicit experience of the movement task involves the inferior premotor cortex. Evidence in patients recovering from brain lesions such as stroke, suggests that similar principles hold for neurorehabilitation as well. The challenging issue is to what degree altered motor strategies afford improvement in function through relearning and neural plasticity.