Speech Production

Functional neuroimaging has dramatically accelerated our understanding of the neural computations underlying speech. Speaking involves interactions between motor planning and execution areas in the frontal lobe, somatosensory areas in the parietal lobe, and auditory areas in the temporal lobe, along with associated subcortical structures. Cortical activities are modulated by two reentrant loops: a basal ganglia loop involved in action selection and initiation and a cerebellar loop involved in generating the finely tuned motor commands that underlie fluent speech. Motor commands descending from the motor cortex to the cranial nerve nuclei are shaped by both feedforward-based and sensory feedback-based control mechanisms.