Motor imagery perspective shapes corticospinal excitability with effector-specific effects

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• Motor imagery (MI) involves mentally simulating movements, activating similar neural pathways as actual actions.
• The influence of imagery perspective on corticospinal excitability across different effectors is not well understood.

Purpose of the Study:

• To investigate how kinesthetic (KMI), first-person visual (VMI-1PP), and third-person visual (VMI-3PP) motor imagery affect corticospinal excitability in upper-arm and hand muscles.

Main Methods:

• Nineteen healthy adults underwent neuronavigated transcranial magnetic stimulation (TMS) synchronized with imagined elbow movements.
• Motor-evoked potentials were recorded from upper-arm and intrinsic hand muscles during different MI conditions and a pacing-only baseline.

Main Results:

• All MI types increased corticospinal excitability compared to baseline.
• VMI-3PP and KMI yielded greater facilitation in upper-arm muscles than VMI-1PP.
• Intrinsic hand muscles exhibited similar facilitation across all MI perspectives.

Conclusions:

• Imagery perspective and effector type interact to modulate corticospinal excitability.
• Proximal muscles are more sensitive to imagery perspective than distal muscles.
• Third-person visual imagery is a viable alternative to kinesthetic imagery for enhancing corticospinal excitability in neurorehabilitation and training.