研究所、轉學考(插大)、學士後-英文題庫下載題庫

While the left hemisphere in the brain is innately predisposed to specialize for language, there is also evidence of considerable plasticity in the right hemisphere during the early stages of language development. Under certain circumstances, the right hemisphere can take over many of the language functions that would normally reside in the left hemisphere. An impressive illustration is provided by children who have undergone a procedure known as hemispherectomy, in which one hemisphere of the brain is surgically removed. This procedure is used to treat otherwise intractable cases of epilepsy. In cases of left hemispherectomy after language acquisition has begun, the children experience an initial period of aphasia. However, depending on the underlying disease that leads to the epilepsy, some children may reacquire a linguistic system virtually indistinguishable from that of normal children. They also show many of the developmental patterns of normal language acquisition. UCLA researchers who have studied many of these children hypothesize that the latent linguistic ability of the right hemisphere is “freed” by the removal of the diseased left hemisphere, which may have had a strong inhibitory effect before the surgery.