Learned control of inter-hemispheric connectivity: Effects on bimanual motor performance

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Science

Background:

• Bimanual movements rely on interactions between primary motor cortices.
• Inter-hemispheric functional coupling, a form of phase-locked brain activity, is thought to mediate these interactions.
• Previous studies suggest a negative correlation between motor performance and functional coupling strength, but causality remains unclear.

Purpose of the Study:

• To investigate the causal role of inter-hemispheric functional coupling in bimanual motor performance.
• To manipulate functional coupling strength and assess its impact on bimanual coordination.
• To test the hypothesis that increased functional coupling deteriorates, and decreased coupling facilitates, out-of-phase bimanual finger-tapping.

Main Methods:

• Utilized an operant conditioning paradigm with real-time magnetoencephalography (MEG) neurofeedback to train participants in volitionally regulating inter-hemispheric functional coupling.
• Participants learned to upregulate and downregulate functional coupling in response to discriminative stimuli.
• Assessed changes in bimanual motor performance (finger-tapping speed ratio) before and after training.

Main Results:

• Participants successfully learned to upregulate and downregulate inter-hemispheric functional coupling.
• A control group showed no significant changes in motor performance post-training.
• The neurofeedback group exhibited a significant decrease in the tapping speed ratio, indicating slower tapping with stronger functional coupling.

Conclusions:

• Results provide evidence for a causal relationship between inter-hemispheric functional coupling and bimanual task performance.
• The findings suggest that modulating functional coupling can directly influence motor coordination.
• This study advances our understanding of neural mechanisms underlying bimanual movements.