Vibration-Induced Kinesthetic Illusions and Corticospinal Excitability Changes

Area of Science:

• Neuroscience
• Motor Control
• Somatosensation

Background:

• Tendon vibration can induce kinesthetic illusions, altering the sense of limb position.
• Corticospinal excitability reflects the excitability of the neural pathway from the motor cortex to the spinal cord.

Purpose of the Study:

• To investigate changes in corticospinal excitability during kinesthetic illusions.
• To examine the role of visual feedback in modulating these changes.

Main Methods:

• Transcranial magnetic stimulation (TMS) was used to elicit motor-evoked potentials (MEPs).
• MEPs were recorded from the flexor carpi radialis (vibrated muscle) and its antagonist, the extensor carpi radialis.
• Kinesthetic illusions were induced via tendon vibration under conditions of open and closed eyes (no visual feedback).

Main Results:

• Kinesthetic illusions induced by tendon vibration facilitated corticospinal excitability in both the vibrated muscle and its antagonist.
• Changes in MEPs of the antagonist muscle differed between open and closed eye conditions.
• This suggests simultaneous, opposing neural influences whose balance is affected by visual input.

Conclusions:

• Kinesthetic illusions are associated with widespread changes in corticospinal excitability.
• Visual conditions modulate the neural processing of somatosensory information during illusions.
• The findings highlight the complex interaction between visual and somatosensory systems in motor control.