Psychophysical research on integration of local motion signals and generation of 2-dimensional motion signals in the human visual system

本研究关注的是人类视觉运动加工的整合过程。众所周知，在人类视觉系统中，在处理的第一阶段检测局部运动信号，并且在第二阶段将第一阶段的输出集成为二维全局运动信号。但其时空特性和整合过程的本质还有待阐明。本研究通过实验研究了局部运动信号间的兼性和抑制性相互作用的刺激依赖性，从而探索了人类视觉运动加工的整合过程。在第一系列的实验中，运动同化的膨胀/收缩和它的空间特性进行了检查，在两帧的明显的运动显示。并且，在第二系列中，在两帧和多帧表观运动显示中研究了刺激时空特性对运动同化和运动对比的影响。两个系列实验的主要结果是：（1）局部一维运动信号之间，以及局部运动信号与全局二维运动信号之间，都存在着相互促进的作用。(2)易化和抑制相互作用之间的相对优势取决于三个刺激参数，即。位移大小、运动显示的帧数和每帧的持续时间等，这些结果将为阐明人类视觉运动加工的整合过程（并帮助建立模型）提供重要线索。

The present research concerns the integrative process of the human visual motion processing. It is well known that in the human visual system, local motion signals are detected at the first stage of processing, and the outputs of the first stage are integrated into two-dimensional global motion signals at the second stage. But the spatio-temporal properties and the nature of the integrative process are yet to be elucidated. The present research examined experimentally the stimulus dependencies of facultative and inhibitory interactions between local motion signals, thereby amied to explore the integrative process of the human visual motion processing. In a first series of experiments, motion assimilation for expansion/contraction and its spatial properties were examined in a two-frame apparent motion display. And, in the second series, the effects of stimulus spatio-temporal properties on motion assimilation and motion contrast were examined in a two- and multi-frame apparent motion display. The main fidings obtained in the two series of experiments are(1) facilitaive interactions exist not only between local one-dimensional motion signals, but also between local signals and global two-dimensional motion signals.(2) relative dominance between facilitaive and inhibitory interactions varies depending on the three stimulus parameters, ie. displacement size, number of frames of the motion display, and duration of each frame.These results will serve as critical cues to elucidate (and help to establish a model of) the integrative process of the human visual motion processing.