Implicit Motor Imagery and the Lateral Occipitotemporal Cortex: Hints for Tailoring Non-Invasive Brain Stimulation

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Motor Control

Background:

• The lateral occipitotemporal cortex is increasingly implicated in implicit motor imagery, particularly in aging populations and neurodegenerative diseases.
• Over-recruitment of visual areas like the occipitotemporal cortex may compensate for declining motor representations during movement imagery.
• This suggests the occipitotemporal cortex as a potential target for non-invasive brain stimulation to improve motor imagery.

Purpose of the Study:

• To investigate the specific roles of the left and right lateral occipitotemporal cortex in implicit motor imagery.
• To determine if this brain region is involved in the mental representation or sensorimotor reactivation aspects of motor imagery.

Main Methods:

• Healthy right-handed individuals performed a hand laterality judgment task.
• Online, high-frequency repetitive transcranial magnetic stimulation (rTMS) was applied over the left and right lateral occipitotemporal cortex.
• Performance was compared between real rTMS and sham stimulation conditions.

Main Results:

• Left hemisphere rTMS significantly decreased accuracy in judging the laterality of right-hand images compared to sham.
• Repetitive transcranial magnetic stimulation (rTMS) did not affect the biomechanical aspects of motor simulation.
• These results indicate a specific role for the lateral occipitotemporal cortex in the mental representation of the dominant hand.

Conclusions:

• The lateral occipitotemporal cortex is involved in the mental representation of the dominant hand in right-handers.
• It does not appear to be involved in reactivating sensorimotor information during motor simulation.
• Findings support the development of combined brain stimulation and cognitive training strategies to enhance motor imagery performance.