结合动、静态视觉信息改善低视力及双眼弱视患者视知觉的研究

视知觉依赖两种信息： 静止的物体投射影像结构信息；物体或观察者的运动产成光流信息。光流表达三维时空关系的能力强，但是它不稳定，一旦运动停止即消失。影像结构表达三维关系的能力弱，但是它稳定，只要物体存在于视野内它即存在。当两种信息共存时，光流把零散的静态影像结构串联起来，赋予其三维时空意义；影像结构保存光流表达的三维关系，形成具身记忆，使观察者在运动结束后仍然能够准确、有效、持久地感知三维关系。.低视力或弱视患者接收到模糊的影像结构和无损的光流信息。在具身记忆中，影像结构的作用是保存（而非直接表达）空间关系；如果妥善利用光流，这些患者则可以完成识别场景、形状及伸手抓握等视知觉任务。本项目通过行为实验验证上述推论，探索最佳运动模式以产生最强光流，并通过运动模型描述预测低视力或弱视者的伸手抓握动作。本项目致力于扩展现有知觉、记忆理论，增进对低视力及弱视视功能的认识，为开创新康复疗法奠定理论基础。

In 3D environments, there are two sources of optical information: image structure and optic flow. Surfaces in the world project image structure that is weak in specifying spatial relations, but enduring. Relative motion between observers and surfaces generates optic flow that powerfully specifies spatial relations, but vanishes when motion stops. Normally, the two interact and compensate for one another’s weaknesses. With on-going motion, optic flow carries one image to the next and spatiotemporally calibrates them. After motion stops, calibrated image structure remains and preserves spatial relations specified by optic flow. Image structure provides embodied memory for situated, active observers...Blurry vision only affects the detection of high spatial frequencies or image structure, but not that of low spatial frequencies or optic flow. According to the theory of embodied memory, optic flow specifies spatial relations and image structure preserves them. Therefore, with unimpaired optic flow but weakened image structure, low vision or amblyopic observers should be able accomplish visually guided tasks, such as scene perception, shape perception and reach-to-grasp. .This study also uncovers the kind of motion that would generate the strongest optic flow contributing to perception and action in low vision and amblyopia. The research team shall build a kinematic model to describe reach-to-grasp in these patients. This model, in return, can predict one’s motor performance given his/her vision and be used as a clinical instrument to assess visual functioning. This project aims to enrich the current understanding of visual functioning and enhance the existing rehabilitation methods to improve the quality of life of low vision and amblyopic patients.