title: Motion direction discrimination training reduces perceived motion repulsion.
abstract: Participants often exaggerate the perceived angular separation between two simultaneously presented motion stimuli, which is referred to as motion repulsion. The overestimation helps participants differentiate between the two superimposed motion directions, yet it causes the impairment of direction perception. Since direction perception can be refined through perceptual training, we here attempted to investigate whether the training of a direction discrimination task changes the amount of motion repulsion. Our results showed a direction-specific learning effect, which was accompanied by a reduced amount of motion repulsion both for the trained and the untrained directions. The reduction of the motion repulsion disappeared when the participants were trained on a luminance discrimination task (control experiment 1) or a speed discrimination task (control experiment 2), ruling out any possible interpretation in terms of adaptation or training-induced attentional bias. Furthermore, training with a direction discrimination task along a direction 150° away from both directions in the transparent stimulus (control experiment 3) also had little effect on the amount of motion repulsion, ruling out the contribution of task learning. The changed motion repulsion observed in the main experiment was consistent with the prediction of the recurrent model of perceptual learning. Therefore, our findings demonstrate that training in direction discrimination can benefit the precise direction perception of the transparent stimulus and provide new evidence for the recurrent model of perceptual learning.
authors.affiliation: Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, 5 Yiheyuan Road, Haidian, Beijing, 100871, China.|PKU-IDG/McGovern Institute for Brain Research, Peking University, 5 Yiheyuan Road, Haidian, Beijing, 100871, China.|Key Laboratory of Machine Perception (Ministry of Education), Peking University, 5 Yiheyuan Road, Haidian, Beijing, 100871, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Jia
authors.affiliation: Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, 5 Yiheyuan Road, Haidian, Beijing, 100871, China. sli@pku.edu.cn.|PKU-IDG/McGovern Institute for Brain Research, Peking University, 5 Yiheyuan Road, Haidian, Beijing, 100871, China. sli@pku.edu.cn.|Key Laboratory of Machine Perception (Ministry of Education), Peking University, 5 Yiheyuan Road, Haidian, Beijing, 100871, China. sli@pku.edu.cn.
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
mesh_terms: D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D055815:Young Adult
keywords: Motion; Perceptual learning; Visual perception