视觉运动追踪的加工过程

视觉运动追踪是运动知觉研究的一个重要领域。通过构建视觉运动追踪的过程模型和分析每个阶段的认知加工任务, 可以帮助人们认识运动物体识别的本质。视觉运动追踪包括目标获取和运动追踪两个加工过程：目标获取阶段的主要任务是将目标与背景分离, 集中注意力加工追踪目标; 运动追踪阶段的主要任务是启动平滑追踪眼动和追赶性眼跳, 并发挥行为水平、眼动水平和神经活动水平的预测机制。目标获取同时受背景和目标的运动特征和身份特征影响; 运动追踪系统发挥预测机制的基础是客体表征连续性, 而客体表征连续性的建立同时依赖于目标时空属性和身份特征的编码加工。因此, 视觉运动追踪是视觉系统对客体运动信息和身份语义信息整合的结果。其中, 客体运动信息的加工特性已经获得了比较广泛的研究, 而语义信息加工机制还有待进一步加强。

The Analysis of Visual Motion Tacking

The aim of visual motion tracking is to capture and track moving objects through a sequence of images. The ability is crucial for the survival of many species. Visual motion tracking proceeds in two main parts: object capture and object tracking. The first step is to discriminate target’s signals from other object signals in the visual context, and then concentrate on encoding target’s motion and identity. The second step is to initiate smooth pursuit eye movements and catch-up saccades, and then predict target trajectory by behavioral response, eye movement or cerebral activity. Visual tracking system has to encode target’s motion features and semantic identity for completing predictive mechanism. In recent years the amount and complexity of data about processing of object’s motion features have increased substantially, whereas data about processing of object’s semantic identity is significantly less.