EEG activity over ipsilateral and contralateral M1 during simple and complex hand tasks: variations with motor...

Area of Science:

• Motor Neuroscience
• Cognitive Neuroscience
• Electrophysiology

Background:

• The role of the ipsilateral primary motor cortex (iM1) in motor skill acquisition is debated, particularly its interaction with task complexity.
• Understanding iM1's functional dynamics during learning is crucial for advancing motor neuroscience.

Purpose of the Study:

• To investigate how electroencephalogram (EEG) activation dynamics in the gamma frequency band over the contralateral (cM1) and ipsilateral (iM1) primary motor cortex change during simple versus complex motor skill acquisition.
• To determine if hand dominance modulates these EEG activation dynamics.

Main Methods:

• A randomized controlled trial involving 48 participants training on simple or complex visuomotor tasks.
• 64-channel EEG recorded brain activity throughout training and retention phases.
• Analysis focused on high-gamma band (50-80Hz) activation over cM1 and iM1.

Main Results:

• Before training, iM1 showed higher high-gamma activation during simple tasks than complex tasks.
• After training, iM1 activation increased for complex tasks and decreased for simple tasks, irrespective of hand used.
• No significant changes in EEG activation were observed over cM1.

Conclusions:

• Task complexity significantly modulates iM1 high-gamma band activation during motor skill acquisition.
• Complex motor skill training enhances iM1 activity, supporting its dynamic, task-dependent role in motor learning.
• Findings suggest iM1 activation scales with task demands, contributing to skill acquisition.