Although language is thought of as a left hemisphere function, there is inc
reasing evidence that the right hemisphere contributes to language processi
ng by identifying the theme of spoken and written language. Using fMRI, we
examined the role played by the right and left hemispheres in making sense
of a conversation. When this process involves implicit appraisal of changes
in the conversation's topic, the neural network has a right hemisphere bia
s and includes Broca's and Wernicke's areas, their right hemisphere homolog
ues, right dorsolateral prefrontal cortex, and the cerebellum. When making
sense of conversation involves appraisal of the conversation's reasoning, h
owever, the network includes Broca's and Wernicke's areas. Thus, right and
left hemisphere systems contribute uniquely to the linguistic skills involv
ed in making sense of a conversation. (C) 2001 Lippincott Williams & Wilkin
s.