Interhemispheric Parietal-Frontal Connectivity Predicts the Ability to Acquire a Nondominant Hand Skill

Area of Science:

• Neuroscience
• Motor Control
• Brain Plasticity

Background:

• Individuals with right dominant hand impairment can compensate using their left hand.
• Compensation may involve the nondominant (right) hemisphere accessing dominant (left) hemisphere functions.
• Understanding these neural mechanisms is crucial for predicting and modulating compensatory abilities.

Purpose of the Study:

• To identify right-hemisphere regions where functional connectivity (FC) predicts left-hand skill acquisition.
• To investigate the neural basis of interhemispheric integration supporting motor compensation.

Main Methods:

• Resting-state functional connectivity (FC) MRI was used in 17 healthy right-handed adults.
• Participants underwent 10 days of left-hand precision drawing training.
• FC from left motor cortex and intraparietal sulcus (IPS) seeds to right-hemisphere regions was analyzed.

Main Results:

• Left-hand skill learning was predicted by convergent FC from the left primary motor cortex and left IPS.
• This predictive connectivity converged onto a specific region within the right superior parietal lobule (SPL).

Conclusions:

• The right SPL may be critical for integrating left-hemisphere motor control mechanisms during compensation.
• This study models how interhemispheric connections support functional compensation after right-hand injury.