Research shows that improvements to motor function, after Constraint Induced Movement Therapy (CIMT), involve changes to the sensorimotor regions of the brain. This study was designed to determine the impact of CIMT on the brain by using Magnetoencephalography (MEG) to measure changes in the sensorimotor cortex. MEG detects magnetic signals produced by the brain in order to examine brain function and its relation to behaviour. The study also assessed whether changes due to CIMT occurred mainly within the motor cortex, sensory cortical areas, or both regions.