Ocular-following responses to unikinetic plaids in children: Evidence for the temporal dynamics of motion integration.

Abstract

Accurate visual motion estimation requires the integration of local component-motion signals into a global, pattern-consistent representation. Unikinetic plaids provide a controlled way to probe this process because a drifting component supplies motion energy while a static oriented component constrains the global solution. This study investigated whether short-latency ocular-following responses (OFRs) in children show the temporal sequence predicted by adult and non-human-primate work. Eight typically developing children (mean age 10.5 years; range 5-16 years) were tested using a pediatric-oriented, non-invasive, high-resolution video-oculography system with marker-based head-motion stabilization. Four unikinetic plaid conditions were presented in a brief protocol, and horizontal and vertical eye displacements were estimated from sparsely sampled image pairs during the first 200 ms after motion onset. A component-sensitive horizontal contrast was evaluated over 80-160 ms, and a pattern-sensitive vertical contrast over 100-200 ms. Bootstrap inference was performed within subject. The component-sensitive response was significant in seven of eight children, the pattern-sensitive response in six of eight, and both effects were present in six of eight participants. These findings provide the first pediatric evidence, to our knowledge, that OFRs to unikinetic plaids can reveal an early component-driven response followed by a later pattern-consistent deviation. The results support the feasibility of marker-stabilized video OFR measurements as a low-demand biomedical signal for studying motion-integration dynamics in children and motivate larger normative and clinical validation studies.