Predictive posture stabilization before contact with moving objects: equivalence of smooth pursuit tracking and...

Area of Science:

• Human motor control
• Neuroscience
• Vision science

Background:

• Postural stabilization is crucial for environmental interaction.
• Anticipatory postural adjustments (APAs) are preemptive posture changes to counteract disturbances.
• APAs are influenced by predictive models using visual and extraretinal motion signals.

Purpose of the Study:

• To investigate the impact of object motion in different visual field sectors on anticipating motion and preparing APAs.
• To compare APAs under central fixation, peripheral fixation, and smooth pursuit eye movements (SPEMs).
• To evaluate the contribution of oculomotor signals (eye velocity, gain) to APAs.

Main Methods:

• Participants interacted with virtual moving objects under varying gaze conditions (central fixation, peripheral fixation, SPEMs).
• APAs were measured based on object approach and different visual field exposures.
• Bayesian model averaging was used to assess the predictive power of oculomotor variables on APAs.

Main Results:

• APAs showed the smallest magnitude during central fixation.
• No significant differences in APAs were observed between SPEM and peripheral fixation conditions.
• Both eye velocity and eye-object velocity gain were significant predictors of APAs.

Conclusions:

• The human visual system accurately perceives peripheral motion for posture stabilization.
• Oculomotor signals play a significant role in modulating APAs.
• Findings suggest potential implications for understanding age-related changes in vision and postural control.