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Updated: Feb 28, 2026
07:24
Using Eye-tracking to Assess the Relative Importance of Visual and Vestibular Input to Subcortical Motion Processing in the Roll Plane
Published on: August 22, 2025
587
Angle of gaze and optic flow direction modulate body sway
Milena Raffi1, Alessandro Piras1, Michela Persiani1
1Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy.
Summary
Eye position influences body sway and postural stability, even without altering leg muscle activity. This highlights the integration of eye movement signals with visual flow for balance control.
Area of Science:
- Neuroscience
- Biomechanics
- Human Physiology
Background:
- Optic flow is vital for maintaining postural stability.
- The interplay between visual stimuli, eye position, and body sway requires further investigation.
Purpose of the Study:
- To investigate how eye position modulates postural muscle activity and body sway during optic flow.
- To determine the integration of extraretinal eye position signals with optic flow for postural control.
Main Methods:
- Stabilometry and surface electromyography (EMG) were used on 24 healthy volunteers.
- Radial optic flow stimuli with manipulated dot speed and fixation point simulated heading and gaze.
- Center of pressure (COP) parameters and muscle activity were analyzed.
Main Results:
- Body sway (COP parameters) was significantly modulated by eye position.
- A significant main effect of body side was observed in COP parameters, with greater oscillations on the right.
- Optic flow and eye position combinations caused non-uniform sway oscillations in females.
- EMG showed significant main effects for muscle and body side, but principal leg muscle activity remained unchanged.
Conclusions:
- Eye position significantly modulates body sway, independent of changes in principal leg postural muscle activity.
- Extraretinal input regarding eye position is crucial and integrated with optic flow for effective body sway control.
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