Modulating hemispheric lateralization by brain stimulation yields gain in mental and physical activity

Area of Science:

• Neuroscience
• Motor Control
• Human Aging

Background:

• Motor imagery, the mental simulation of movement, is crucial for skill acquisition and rehabilitation.
• The transfer of motor imagery benefits to actual physical performance is limited.
• Brain stimulation techniques offer potential to enhance motor imagery and performance.

Purpose of the Study:

• To investigate the effects of bilateral transcranial direct current stimulation (tDCS) on neural lateralization during motor imagery and performance.
• To examine the polarity-dependent effects of tDCS on sensorimotor areas.
• To assess the relationship between neural changes and behavioral improvements in motor skills.

Main Methods:

• A double-blind, cross-over, sham-controlled study involving 26 healthy older adults (mean age 67.1 years).
• Bilateral tDCS applied over sensorimotor areas during unilateral motor imagery and a physical motor task.
• Electroencephalography (EEG) recorded to measure neural lateralization.
• Behavioral assessment of motor performance.

Main Results:

• tDCS induced polarity-dependent changes in neural and behavioral outcomes.
• Anodal stimulation contralateral to the hand enhanced neural lateralization during motor imagery and improved motor performance.
• Cathodal stimulation contralateral to the hand reduced hemispheric lateralization.
• Neural lateralization changes correlated with behavioral improvements.

Conclusions:

• Bilateral tDCS can modulate sensorimotor neural lateralization.
• tDCS has the potential to enhance both mental motor imagery and physical motor performance.
• These findings support the translational application of tDCS for improving motor skills in various populations.