Development and plasticity of visual and vestibular generated eye movements

Area of Science:

• Neuroscience
• Ophthalmology
• Developmental Biology

Background:

• The vestibulo-ocular reflex (VOR) and visual pursuit (VP) are crucial for maintaining stable vision during head and body movements.
• Understanding the maturation of these systems in children is key to identifying developmental timelines and potential deficits.

Purpose of the Study:

• To investigate the developmental trajectory of horizontal eye movements mediated by the VOR and VP systems in children compared to adults.
• To determine the roles of visual and extra-retinal signals in the development of VOR gain and suppression.

Main Methods:

• Examined slow-phase horizontal eye movements in normal children (9-16 years) and adults during sinusoidal stimulation.
• Assessed VOR and VP performance with visual and non-visual (extra-retinal) target information.

Main Results:

• Children (9-12 years) demonstrated immature VP and VOR suppression but mature VOR enhancement, suggesting a lag in extra-retinal signal processing.
• The VOR gain could be adjusted to a high value, but augmentation/depression with non-visual cues was impaired.
• A parallel development was observed between VP and VOR suppression, alongside VOR gain modification.

Conclusions:

• Retinal and vestibular contributions to ocular stability mature before the development of extra-retinal signals.
• The mature central nervous system integrates both retinal and extra-retinal signals for adaptive VOR gain regulation and stable visual pursuit.
• VP and VOR mechanisms appear indirectly coupled during visual-vestibular interaction tasks.