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Updated: Jan 9, 2026
Frame-by-Frame Video Analysis of Idiosyncratic Reach-to-Grasp Movements in Humans
Published on: January 15, 2018
The Long-Term Absence of Static Stereopsis Cultivates Adaptive Planning of Reaching-to-Grasp
Pin Yang1,2, Geoffrey P Bingham2, Zhongting Chen1,3
1East China Normal University (ECNU), School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
Purpose:
To determine how the absence of stereopsis affects sensorimotor adaptation in visually guided reaching-to-grasp by comparing slant perception and depth-directed motor control between adults with long-term stereoblindness and typically sighted adults.
Methods:
Twenty-four adults (12 stereoblind, 12 typically sighted) completed a slant-matching task (perceptual estimate of surface orientation) and a reaching-to-grasp task (motor execution in depth). Outcomes indexed perceptual accuracy and grasp kinematics, including approach speed and the timing of grip alignment to surface slant.
Results:
Groups performed comparably on slant matching, but the stereoblind group adopted distinct grasping strategies, characterized by a faster approach to the target and delayed grip alignment relative to controls.
Conclusions:
Findings indicate adaptive reorganization of motor planning following long-term deprivation of static binocular (disparity) cues. The visuomotor system appears to recalibrate the balance between feedforward and feedback control-placing greater weight on real-time sensory information when anticipatory planning is constrained-highlighting flexible, ecological pathways for development and adaptation.
