The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science

by Norman Doidge

From his research Grafman has identified four kinds of plasticity. The first is “map expansion,” described above, which occurs largely at the boundaries between brain areas as a result of daily activity. The second is “sensory reassignment,” which occurs when one sense is blocked, as in the blind. When the visual cortex is deprived of its normal inputs, it can receive new inputs from another sense, such as touch. The third is “compensatory masquerade,” which takes advantage of the fact that there’s more than one way for your brain to approach a task. Some people use visual landmarks to get from place to place. Others with “a good sense of direction” have a strong spatial sense, so if they lose their spatial sense in a brain injury, they can fall back on landmarks. Until neuroplasticity was recognized, compensatory masquerade—also called compensation or “alternative strategies,” such as switching people with reading problems to audio tapes—was the chief method used to help children with learning disabilities. The fourth kind of plasticity is “mirror region takeover.” When part of one hemisphere fails, the mirror region in the opposite hemisphere adapts, taking over its mental function as best it can.

Four kinds of plasticity.