Oscillatory dynamics of response competition in human sensorimotor cortex.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Motor Control

Background:

• Non-human primate studies suggest simultaneous activation of competing motor responses in the (pre)motor cortex.
• Human studies are limited due to experimental designs often comparing between hemispheres, allowing simultaneous execution.

Purpose of the Study:

• To provide compelling human evidence for motor cortex competition between different movement plans.
• To investigate response competition within a single motor cortex by ruling out simultaneous execution of alternative responses.

Main Methods:

• Utilized a unimanual Eriksen flanker paradigm with magnetoencephalography (MEG).
• Assigned alternative responses to flexion and extension of the right index finger.
• Analyzed beta-band (17-29 Hz) and high-gamma band (60-90 Hz) power changes in the pre-response motor cortex.

Main Results:

• Stronger decrease in pre-response motor cortex beta-band power observed for stimuli inducing response competition.
• An increase in pre-response mid-frontal high-gamma band power was associated with response competition.
• Larger gamma-band effect sizes correlated with increased behavioral response delay.

Conclusions:

• Provides evidence for the co-activation of competing responses in the human brain.
• Findings align with previous neurophysiological evidence from non-human primates.
• Demonstrates motor cortex competition within a single hemisphere, ruling out simultaneous execution.