Neuroplasticity

by Moheb Costandi

The brain is an extremely complex organ, and neurosurgery always runs the risk of causing collateral damage to areas involved in important functions such as language and movement. To avoid such damage, Penfield deliberately kept his patients conscious while he electrically stimulated the cortex, so that they could report their experiences back to him. When he stimulated the postcentral gyrus, for example, patients described feeling a touch sensation on some part of their body; stimulation of the precentral gyrus caused muscles in the corresponding part of the body to twitch; and stimulation of parts of the left frontal lobe interfered with the ability to speak. In this way he could delineate the boundaries of the abnormal tissue and remove it without inflicting damage on the surrounding tissue.