Thompson-Schill, S.
University of Pennsylvania
For over a century, the relationship between left prefrontal cortex and language processing has been accepted, yet the precise characterization of this link remains elusive. Recent advances in both the psycholinguistic study of language processing and the neuroscientific study of frontal lobe function have converged on an intriguing possibility: The demands to resolve competition between incompatible characterizations of a linguistic stimulus may recruit top-down cognitive control processes mediated by prefrontal cortex. Under this account, the brain region traditionally known as “Broca’s area” – one of the principle language centers in classical models of language dysfunction – may be better described in attentional than linguistic terms. This hypothesis draws on a large body of research into the function of prefrontal cortex, and contrasts with other more domain-specific accounts of the function of Broca’s area. I will present both functional neuroimaging data from young, healthy volunteers and lesion-deficit analyses of patients with focal brain damage that jointly provide support for the regulatory hypothesis of left prefrontal cortex involvement in language processing. I will emphasize studies of single word production, but I will also discuss parallel findings beyond the domain of speech. Evidence of shared regulatory mechanisms across domains has implications for the psychological and neural architecture of language and may broadly inform the study of both linguistic and nonlinguistic cognitive processes.