Department of Psychology, University of Washington, 119A Guthrie Hall Box 351525, Seattle, WA, 98195, USA.
Department of Ophthalmology and Visual Sciences, University of British Columbia, 4480 Oak Street, Vancouver, BC, V6H 3V4, Canada.
Sci Rep. 2021 Jan 11;11(1):375. doi: 10.1038/s41598-020-78636-0.
Effective binocular vision is dependent on both motor and perceptual function. Young children undergo development of both components while interacting with their dynamic three-dimensional environment. When this development fails, eye misalignment and double vision may result. We compared the range of image disparities over which young children display reflex motor realignment of their eyes with the range over which they report a single versus double percept. In response to step changes in the disparity of a 2.2° wide stimulus, 5-year-olds generated an adult-like reflex vergence velocity tuning function peaking at 2° of disparity, with a mean latency of 210 ms. On average, they reported double vision for stimulus disparities of 3° and larger, compared to 1° in adult reports. Three-year-olds also generated reflex vergence tuning functions peaking at approximately 2° of disparity, but their percepts could not be assessed. These data suggest that, by age 5, reflex eye realignment responses and percepts driven by these brief stimuli are tightly coordinated in space and time to permit robust binocular function around the point of fixation. Importantly, the plastic neural processes maintaining this tight coordination during growth control the stability of visual information driving learning during childhood.
有效的双眼视觉依赖于运动和感知功能。年幼的孩子在与动态的三维环境互动时，会同时发展这两个部分。如果这种发展失败，可能会导致眼睛斜视和复视。我们比较了儿童表现出眼睛反射性运动重新对准的图像视差范围，以及他们报告单视和复视的范围。对于 2.2°宽刺激的视差阶跃变化，5 岁儿童产生了类似于成人的反射会聚速度调谐功能，在 2°视差处达到峰值，平均潜伏期为 210ms。平均而言，他们报告说对于 3°及更大的刺激视差会出现复视，而成年人的报告则为 1°。3 岁儿童也产生了在大约 2°视差处达到峰值的反射会聚调谐功能，但无法评估他们的感知。这些数据表明，到 5 岁时，反射性眼睛重新对准的反应和由这些短暂刺激驱动的感知在空间和时间上紧密协调，从而在注视点周围实现稳健的双眼功能。重要的是，在生长过程中控制这种紧密协调的可塑性神经过程，控制着儿童学习期间驱动视觉信息的稳定性。
