Premotor cortex modulates somatosensory cortex during voluntary movements without proprioceptive feedback.

Area of Science:

• Neuroscience
• Motor Control
• Sensory Perception

Background:

• Movement perception typically relies on sensory feedback.
• The role of efference copies (internal predictions of motor commands) in movement perception is not fully understood.
• Proprioception, the sense of body position and movement, is crucial for this feedback.

Purpose of the Study:

• To investigate the role of efference copies in movement perception.
• To determine if movement perception can occur without direct proprioceptive feedback.
• To explore the neural mechanisms underlying movement perception in the absence of sensory input.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to monitor brain activity in healthy human participants.
• A transient ischemic nerve block was employed to eliminate proprioceptive feedback during voluntary movements.
• Participants performed self-initiated movements while their brain responses were recorded.

Main Results:

• Primary somatosensory cortex activation was preserved despite the absence of proprioceptive feedback.
• Increased interaction between the premotor cortex and the somatosensory cortex was observed during voluntary movements.
• This suggests a predictive mechanism contributing to movement perception.

Conclusions:

• Movement perception is partially mediated by the prediction of sensory consequences, utilizing efference copies.
• The premotor cortex plays a key role in generating these predictions.
• This finding highlights the brain's predictive capabilities in constructing our sense of agency and movement.