Optimal Human Passive Vestibulo-Ocular Reflex Adaptation Does Not Rely on Passive Training.

Area of Science:

• Neuroscience
• Human Physiology
• Motor Control

Background:

• The vestibulo-ocular reflex (VOR) stabilizes vision during head movements.
• Visual-vestibular mismatch stimuli drive VOR motor learning.
• Training context may influence VOR adaptation.

Purpose of the Study:

• To compare active (self-generated) versus passive (externally imposed) head rotation training for VOR adaptation.
• To assess the short-term retention of active and passive VOR responses.
• To determine if training context affects VOR adaptation and retention.

Main Methods:

• Ten subjects underwent six 1.5-hour sessions comparing active and passive head impulse VOR adaptation training.
• Training involved a 15-minute period of VOR gain increment.
• VOR responses were measured in darkness at various intervals post-training (10-min, 20-min, and 60-min).

Main Results:

• Mean VOR response increased by approximately 10% towards the adapting side and 2% towards the non-adapting side.
• No significant difference was found in VOR adaptation or retention between active and passive training.
• Exposure to a de-adaptation stimulus was the only factor affecting retention.

Conclusions:

• Active and passive VOR training yield similar adaptation and retention effects.
• Active VOR adaptation training can effectively adapt the passive VOR.
• VOR adaptation is retained for at least 1 hour in the absence of visual feedback that drives de-adaptation.