Researchers Map Brain Circuit That Filters Background Noise During Speech

The discovery of the corollary discharge circuit offers insights into schizophrenia and could lead to new diagnostic tools for auditory disorders.

Scientists identified a brain circuit linking the motor and auditory cortices that helps differentiate self-generated speech from external sounds.
The corollary discharge signal originates in the motor cortex's precentral gyrus and travels to the auditory cortex's superior temporal gyrus within milliseconds.
Disruptions in this circuit are linked to auditory hallucinations in schizophrenia and may also contribute to stuttering.
The findings were based on over 3,200 brain activity recordings from epilepsy patients undergoing surgery who participated in speech experiments.
Researchers plan to explore noninvasive diagnostic methods for schizophrenia and further study the circuit's role in auditory hallucinations.