Speech motor cortex (ventral sensorimotor cortex)

The strip of pre- and post-central cortex along the ventral (inferior) sensorimotor gyrus that represents the lips, jaw, tongue, larynx and pharynx, the effectors of speech. High-density recordings here reveal a somatotopic but heavily overlapping and dynamic map: neural populations encode not static muscle activations but coordinated articulatory gestures and their temporal sequencing, with a distinct laryngeal representation contributing voicing and pitch control.

Because this cortex drives the vocal tract directly, it stays active and decodable during attempted speech even when the descending pathways are interrupted, by brainstem stroke, ALS or high cervical injury, which is why almost every high-performance speech neuroprosthesis targets it, whether via subdural high-density ECoG over its surface or intracortical arrays in the dorsal precentral gyrus (area 6v).