Neuroplasticity within the parieto-frontal network for action control

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Humans' primary means of interacting with the world is through reaching and grasping visual objects in the environment. Remarkably, these actions remain very precise across the lifespan, despite the ever-changing state of our musculoskeletal system (e.g. change in limb inertia due to growth, loss of muscle tone due to ageing). In order to adapt our motor behaviour to these changing biomechanical conditions, cortical networks must reorganize (i.e. a process called sensorimotor learning). Neuroimaging research has highlighted the key role of 2 connected regions, the posterior parietal cortex (PPC) and the dorsal premotor cortex (PMd), for the planning and control of arm reaching movements. Yet, the principles by which these regions reorganize during sensorimotor learning remain largely unknown. In particular, it is unclear whether adaptation of our movements is associated with changes in grey matter structure within the PPC and PMd, or with changes in the white matter fiber tracts that connect them. In this light, the objective of the present research program is to study changes in functional and anatomical connectivity between the PPC and PMd during sensorimotor learning. Using advanced neurophysiological methods targeting brain function and structure [functional magnetic resonance imaging (fMRI), electroencephalography (EEG), diffusion tensor imaging (DTI) and transcranial magnetic stimulation (TMS)], my program looks to link learning-related changes in motor behaviour to changes in the underlying neural circuitry. In doing so, it will provide novel insight into a central issue in systems neuroscience: understand how different brain regions communicate to coordinate our actions. My research program on neuroplasticity in the parieto-frontal network will contribute, among other things, to improve rehabilitation in brain-injured patient populations (e.g. stroke), as many interventions exploit principles of cortical reorganization to "bypass" lesioned areas and recruit new regions to achieve lost function.