PET activation and language

Brain activation studies using positron emission tomography (PET) to study language have produced a breakthrough in our understanding of the neural basis of language over the past decade. A neural basis for the visual lexicon and for auditory verbal short term memory components have been proposed. Wernicke's and Broca's areas are being recast in terms of localized components of phonological input and output. Some classical regions, such as the arcuate fasciculus, are having their "classical" roles questioned, while other regions, such as the basal temporal language zone, are growing progressively in terms of their recognized importance. Finally, other areas, such as the anterior cingulate and the left inferior prefrontal area, seem to be activated across a range of tasks, but their exact processing roles remain a matter of some debate.