Short and long-term postural learning to withstand galvanic vestibular perturbations

Area of Science:

• Neuroscience
• Vestibular System Physiology
• Motor Control

Background:

• Postural responses to vestibular stimulation are critical for balance.
• Understanding adaptation to repeated vestibular perturbation is key for clinical applications.

Purpose of the Study:

• To investigate changes in postural responses to repeated galvanic vestibular stimulation (GVS) over consecutive days and after a long-term interval.
• To explore the underlying adaptation mechanisms, including sensory reweighting and post-exposure consolidation.

Main Methods:

• 21 healthy volunteers underwent daily bipolar GVS for 5 consecutive days.
• Postural responses, measured by torque variance, were assessed during GVS.
• Responses were re-evaluated after a 3-month interval.

Main Results:

• A significant day-to-day reduction in torque variance was observed, indicating adaptation.
• Reduced postural responses after 5 days were retained after 3 months.
• GVS failed to increase torque variance compared to quiet stance, suggesting sensory reweighting.

Conclusions:

• Adaptation to GVS occurs primarily after stimulation exposure, akin to motor learning consolidation.
• Repeated vestibular assessments require consideration of these adaptation effects.
• Spaced intervals in vestibular rehabilitation may enhance learning and functional recovery.