ABSTRACT
Dynamic scanning methods have been developed to monitor blood flow, oxygen use and electrical activity in the brain, which can be correlated with particular language tasks that subjects are carrying out at the same time. The search for localized brain centers for speech and language has a long and interesting history. The first group of neurologists to search for an area of the brain dedicated to language function was the phrenologists of the early nineteenth century. As early as 1836, John Abercrombie, a prominent Scottish physician, published data from which the association of left-brain damage with linguistic deficits was clear. If the drug is delivered to the language side of the brain, a temporary paralysis of language function is experienced. The patient stands with both arms extended forward from the shoulders. Converging evidence from studies of aphasia, sodium amytal injection, split-brain patients, and tachistoscopic and dichotic presentation points to left-hemisphere dominance for language organization and processing in most humans.
