Motor cortex activation induced by a mirror: evidence from lateralized readiness potentials

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• Motor cortex activation occurs during both self-executed and observed movements.
• Previous research suggests shared neural pathways for action execution and observation.

Purpose of the Study:

• To investigate if observing one's own hand movements via a mirror activates motor regions for both the moving and non-moving hands.
• To explore the neural correlates of self-observation of movement.

Main Methods:

• Utilized the lateralized readiness potential (LRP), an electrophysiological measure of premotor cortex activation.
• Recorded evoked responses to hand movements while subjects viewed their performing hand in a sagittal mirror.
• The mirror created the illusion that the left hand was performing the task, while the right hand was actually moving.

Main Results:

• Reliable LRPs were observed in relation to the visually perceived hand.
• This indicates significant motor cortex activity in the hemisphere contralateral to the inactive hand.
• Demonstrated that observing one's own hand movement activates the motor cortex of the non-moving hand.

Conclusions:

• Observing one's own hand movements through a mirror engages the motor cortex of both the moving and the non-moving contralateral hand.
• This suggests a shared neural representation for observed and executed actions, even when the observed action is one's own.
• The findings contribute to understanding the neural basis of self-perception and motor control.