Broca's Area and Language Processing: Evidence for the Cognitive Control Connection

A long-standing pursuit in cognitive neuropsychology has been to understand the role of Broca's area in language processing. Although a prevailing view has been to equate this region with grammatical abilities in both production and comprehension, a host of recent evidence from brain imaging and patient research has revealed a rather general role for this patch of cortex in complex cognition, even when grammatical performance is untapped-namely, that it regulates mental activity when there is need to resolve among competing representations. In this light, a recent proposal hypothesizes that this broad 'cognitive control' function of Broca's area similarly serves language processing: Broca's area is responsible for biasing production and comprehension processes when there are strong demands to resolve competition among incompatible characterizations of linguistic stimuli. Some questions that have been asked within this framework are as follows: Does Broca's area help speakers produce an appropriate word when many alternatives are equally plausible? Does it permit readers and listeners to successfully understand words and sentences, even when the input is ripe for misinterpretation? In the current article, we review new empirical evidence from various fields that supports such an account. A central piece to this discussion is how careful scrutiny of language performance, under varying degrees of cognitive control demands, may shed light on how to suitably describe the idiosyncratic language traits of patients with focal Broca's area damage, who are decidedly not agrammatic.