Aspects of speech production represented in inferior frontal gyrus

The inferior frontal gyrus (IFG), particularly Broca’s area, has long been implicated in speech production, yet its precise role in grammatical processing remains unclear. Damage to this region can result in agrammatism, characterized by omissions of grammatical elements and simplified sentence structures. While prior work suggests involvement of IFG in syntax comprehension and tense processing, its contribution to real-time grammatical processing during speech remains debated.

In this study, we recorded broadband neural activity from a participant implanted with a 64-channel microelectrode array over posterior IFG at the border of areas 44 and 6v. Spike-band activity was recorded during a sentence completion task. Our results indicate that IFG encodes information related to grammatical features, including grammatical number and tense, prior to speech production.

These findings provide new insight into the neural dynamics of grammatical processing during speech and may inform future brain–machine interface approaches aimed at restoring communication in individuals with speech impairments.