Abstract
Purpose: When we make saccadic eye movement toward a target object, which is displaced across saccade, it is easy to detect the displacement. But in the case of the background it is harder to detect its displacement. The visual system seems to consider that the large stimulus extending in the peripheral visual field is stable. In the present study we examined effects of peripheral vision on detecting displacement of a background across saccade.
Methods: We used a multi-colored Mondrian pattern as the background stimulus. The background covered the whole visual field of the subject. The subject made a 16 deg saccade toward the target located in the right side of the fixation point. During saccade the background of the target were shifted in 2 deg either leftward or rightward or not at all. The target and its gray surround of a certain diameter did not shift so that the subject had to utilize the peripheral visual field to detect displacement of the background. The subject responded whether he perceived any change of the stimulus.
Results: We found that the size of the target surround did not influence on performance of detecting displacement of the background. This indicates that the vicinity of the target is not important for detecting displacement of the background, and that the far peripheral visual field might have significant role.
Conclusions: It is likely that our visual system utilizes the peripheral visual field to detect displacement of the background, which means that the peripheral vision may judge the outside world stable.