Grant: CIHR Fellowship

The ability to control ongoing movements is a critical component of brain functions allowing us to interact with the world. In general, such control depends on the state of the body perceived from visual information and proprioceptive feedback provided by muscles afferents. While the integration of vision and proprioception has been thoroughly investigated during movement planning, their integration during the execution of motor actions remains largely unexplored. In particular, the two sensory systems do not reach the motor cortical regions at the same time, which complicates multi-sensory integration substantially. We will investigate this issue by using a robotic exoskeleton that allows planar movements of the upper limb and can apply loads at the shoulder and elbow joints. The full system, mounted with a virtual reality display, will allow us to selectively perturb the limb mechanics and/or alter the visual information given to the participants about the location of their limb and target goals. We will quantify the timing and contribution of each sensory system by measuring their effect on motor commands from movement and electromyography recordings. The role of specific brain regions in this multi-sensory integration process will be addressed by means of transcranial magnetic stimulation. The control mechanisms underlying multi-sensory integration for motor control are of prime interest, as we constantly need to interact with a non-static world and respond to changes in the environment that we perceive from the visual and proprioceptive sensory systems. The expected results will impact our fundamental understanding of the neural control of movement and support clinical research on the neurological disorders affecting sensorimotor coordination.