How Your Brain Conducts the Symphony of Speech

"In the mid-1990s, I was studying how the brain processes signed versus spoken language using then cutting-edge fMRI technology. We wanted to know if the same or different brain areas were involved in speaking and signing. Deaf signers and hearing talkers were asked to sign or silently name pictures. We found that similar brain areas were involved in both. Interesting."

"Yet this apparent simplicity masks one of the most remarkable feats your brain performs daily. Consider this: An 18-month-old can form words reasonably well but won't master toilet training for another year. Meanwhile, our closest evolutionary relatives-despite their intelligence and dexterity-cannot speak at all. This is not because their mouth is anatomically incapable of speech, it's because speech is difficult to coordinate, and apes lack the brain networks to do it."

Speaking is a complex sensorimotor ability that appears effortless but requires specialized brain networks. Early language emergence in toddlers contrasts with delayed development of other skills and the inability of apes to speak, indicating neural, not anatomical, constraints. fMRI studies reveal that auditory cortex activates during silent speech tasks, suggesting internal auditory predictions or sensory grounding of speech production. A small, unexpected activation in left auditory cortex during silent naming implies crossmodal integration between motor plans and sensory expectations. Combining linguistic theory with motor-control frameworks yields a unified model explaining how sensory systems and predictive mechanisms enable fluent speech.

Read at Psychology Today