Making sense during conversation: an fMRI study.

Although language is thought of as a left hemisphere function, there is increasing evidence that the right hemisphere contributes to language processing 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 bias and includes Broca's and Wernicke's areas, their right hemisphere homologues, right dorsolateral prefrontal cortex, and the cerebellum. When making sense of conversation involves appraisal of the conversation's reasoning, however, the network includes Broca's and Wernicke's areas. Thus, right and left hemisphere systems contribute uniquely to the linguistic skills involved in making sense of a conversation.