Psychophysical Analysis of Adaptation Phenomena to Reveal Human Brain Mechanism for Visual Motion

摘要

After prolonged viewing of motion in a given direction, the ability of human subjects to detect test stimuli moving in the same direction is selectively impaired (direction-selective threshold elevation), and illusory motion in the opposite direction (motion aftereffect) is seen in physically static patterns or in directionally-ambiguous flickering patterns. Psychophysical analysis of these motion adaptation phenom- ena revealed the mechanisms of cortical information processing of visual motion. That is, first-order motion (of luminance-defined patterns) and second-order motion (of higher-order complex features) are detected separately by specialised motion sensors, then integrated at a higher processing level. It is also found that adaptation of different processing stage(s) gives rise to motion adaptation phenomenon of differeny types.