Motion-in-depth direction discrimination in dynamic random dot stereogram: The role of visual perceptual training
Résumé
Stereopsis is not only the perception of static depth information, but also involves the ability to detect dynamic stereoscopic motion. This study investigated the motion-in-depth (MID) perception in dynamic random dot stereogram (DRDS) among the population of inexperienced normal vision observers, and the role of visual perceptual training for MID perception. There were three sessions in the main experiment: in the pre-training session, subjects were instructed to discriminate the motion direction of DRDS moving in depth (toward or away from the observer). Then subjects went through a perceptual training session to improve their sensitivity for the motion detection discrimination. A post-training session was carried out to evaluate the outcome of the training process. A control experiment involving only pre-training and post-training sessions was carried out to clarify the influence of repeated practice on visual performance improvement. Participants showed low direction discrimination ability for MID perception of DRDS in the pre-training session, their performance was significantly improved after the perceptual training session. However, large individual difference existed for fully perceiving the binocular disparity information during perceptual learning session. Moreover, the training effect was equivalently retained after six months. The subjects' performances in the control experiment did not show significantly difference between pre-training and post-training sessions. These findings demonstrate that difficulties for DRDS motion perception exist for inexperienced observers, and highlight the role of visual perceptual training.