Parietofrontal oscillations show hand-specific interactions with top-down movement plans

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• Generating hand-specific reach plans requires integrating limb-specific signals with movement strategies.
• Previous research explored hand-target interactions in simple tasks, but whole-brain timing and distribution for complex, instruction-dependent strategies remain unclear.

Purpose of the Study:

• To identify cortical regions showing hand specificity.
• To determine how these regions interact with instructed motor plans.
• To investigate the timing and distribution of hand-specific signal integration in action planning.

Main Methods:

• Magnetoencephalography (MEG) was used to record brain activity.
• Participants performed a pointing task with either their left or right hand under different pro/anti instructions.
• Analysis focused on beta band power changes in specific cortical regions of interest.

Main Results:

• Eight bilateral regions, including M1, S1, SMG, and aIPS, showed hand-specific beta band power changes.
• M1, SMG, SPOC, and aIPS exhibited interactions between hand specificity and the instructed motor plan.
• Hand-specific signals emerged early, while hand-motor interactions occurred closer to movement onset.

Conclusions:

• Instruction-dependent motor plans originate in the frontal cortex.
• These plans interact with hand-specific parietofrontal signals before movement onset.
• This process generates distinct, hand-specific motor behaviors.