Fine modulation in network activation during motor execution and motor imagery

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Motor Control

Background:

• Motor imagery involves mental rehearsal of movements without physical action.
• Distinctions exist between visual imagery (VI) and kinetic imagery (KI).
• Previous research shows differing brain activation patterns between execution (E) and imagery, but functional connectivity remains unexplored.

Purpose of the Study:

• To investigate and elucidate the functional connectivity differences between motor execution (E), visual imagery (VI), and kinetic imagery (KI).
• To understand the inter-relationships among brain networks supporting these motor behaviors.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to capture brain activity.
• Structural equation modeling (SEM) was used to analyze network inter-relationships.

Main Results:

• The brain networks underlying E, VI, and KI are not identical, despite significant overlap between E and KI.
• Motor cortex (M1) inputs, facilitatory during E, were inhibitory during KI, suggesting a mechanism to prevent overt movements.
• A significant connection between the superior parietal lobule and the supplementary motor area was identified in both VI and KI.

Conclusions:

• Motor execution and different types of motor imagery engage distinct functional brain networks.
• The inhibitory effect on M1 during kinetic imagery is a key finding for understanding motor control and inhibition.
• The superior parietal lobule-SMA pathway is crucial for both visual and kinetic motor imagery.