Neurophysiological Evidence of Sensory Prediction Errors Driving Speech Sensorimotor Adaptation

Area of Science:

• Neuroscience
• Cognitive Science
• Speech Science

Background:

• Sensorimotor adaptation allows learning movements from experience.
• Implicit learning, often unaware, is thought to stem from sensory prediction errors.
• Direct neurophysiological evidence linking prediction errors to adaptation was lacking.

Purpose of the Study:

• To investigate the neurophysiological basis of implicit sensorimotor adaptation.
• To examine the role of sensory prediction errors in speech adaptation.
• To provide direct evidence for prediction error-driven adaptation.

Main Methods:

• Used magnetoencephalography (MEG) to image auditory cortex activity.
• Measured speaking-induced suppression (SIS) as a neural marker of auditory prediction errors.
• Analyzed SIS changes during implicit speech adaptation to altered auditory feedback.

Main Results:

• Reduced SIS in early learning correlated positively with behavioral adaptation.
• No SIS reduction was observed in a control group without adaptation.
• Increased SIS at learning plateau indicated minimal prediction errors during no-further-adaptation.

Conclusions:

• Provides the first direct neurophysiological evidence that sensory prediction errors drive sensorimotor adaptation.
• Supports the hypothesis that discrepancies between predicted and actual sensory feedback are crucial for motor learning.
• Highlights the role of the auditory cortex in processing prediction errors during speech adaptation.