Scientists found that this map is constantly changing according to how you use your body. For example, braille readers have much bigger fingertips because they use them so much more, and violin players have larger left hands because they are used to play the instrument.
When a part of the body is used less, such as an arm and hand affected by a neurological condition, its representation on the brain has been shown to shrink. Children with hemiplegia have been found to have a much smaller representation of their affected arm and hand on their brain compared to their unaffected side.
Constraint induced movement therapy has been shown to increase the size of the affected arm on the brain. The increase in size has remained when followed up 6 months later. So CIMT affects not just the physical arm and hand, but actually causes cortical reorganisation in the brain that lasts. It is the changes to the brain that allow for the improvements with CIMT to continue long after the treatment has completed.