Scientists have discovered that the brain’s sensory systems play a much larger role in speech learning than previously believed.
New research suggests that learning to speak a new language, or recovering speech after injury, relies more heavily on the brain’s sensory systems than on regions responsible for controlling movement. The findings, from researchers at McGill University and the Yale School of Medicine, could influence future theories of speech learning and help improve speech recognition and brain-speech technologies.
Scientists have long believed that learning and remembering the movements involved in speaking depended mainly on motor regions of the brain that control the face and mouth. The new study challenges that view, pointing instead to the importance of auditory and somatosensory regions that process sound and physical sensation.
“Sensorimotor neuroscience has traditionally focused on frontal motor areas as the principal drivers of movement. This study changes that understanding by showing that human speech learning is extensively sensory in nature,” said David Ostry, Professor of Psychology at McGill University.
The findings may also guide the development of technologies designed to restore speech after conditions such as stroke by incorporating sensory processing to improve performance and usability.
Retention tested through brain stimulation
To investigate how sensory brain regions contribute to learning and retaining speech movements, researchers altered participants’ speech in real time and played the modified sounds back through headphones. This forced participants to adapt their speech patterns, triggering speech motor learning.
The team then used transcranial magnetic stimulation (TMS), a noninvasive brain stimulation method, to temporarily disrupt activity in three areas linked to speech: the auditory cortex, the somatosensory cortex, and the motor cortex. Researchers tested participants again 24 hours later to measure retention.
The scientists predicted that interfering with a brain region essential for speech learning would weaken retention, while disrupting a less important region would have little effect.
The results showed that disrupting either the auditory or somatosensory cortex significantly reduced participants’ ability to retain newly learned speech movements. Disrupting the motor cortex, however, had no measurable effect.
“Our study challenges the assumption that new speech memories are solely reliant on changes in motor areas of the brain. Instead, it underscores the importance of changes in auditory and somatosensory brain areas in shaping how we learn to speak,” said study co-author Nishant Rao, Associate Research Scientist at Yale University.
The role of brain plasticity
The research is part of a larger effort to understand how plasticity in the brain’s sensory systems supports movement learning and memory. It builds on earlier studies of upper limb movement showing that disrupting the sensory cortex can interfere with learning and retaining new motions.
Future studies will focus on identifying the brain circuits involved in learning and testing sensory-based therapies for movement disorders, especially stroke rehabilitation.
Reference: “Sensory basis of speech motor learning and memory” by Nishant Rao, Rosalie Gendron, Timothy F. Manning and David J. Ostry, 24 April 2026, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2525468123
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