title: Perceptual Learning at a Conceptual Level.
abstract: Humans can learn to abstract and conceptualize the shared visual features defining an object category in object learning. Therefore, learning is generalizable to transformations of familiar objects and even to new objects that differ in other physical properties. In contrast, visual perceptual learning (VPL), improvement in discriminating fine differences of a basic visual feature through training, is commonly regarded as specific and low-level learning because the improvement often disappears when the trained stimulus is simply relocated or rotated in the visual field. Such location and orientation specificity is taken as evidence for neural plasticity in primary visual cortex (V1) or improved readout of V1 signals. However, new training methods have shown complete VPL transfer across stimulus locations and orientations, suggesting the involvement of high-level cognitive processes. Here we report that VPL bears similar properties of object learning. Specifically, we found that orientation discrimination learning is completely transferrable between luminance gratings initially encoded in V1 and bilaterally symmetric dot patterns encoded in higher visual cortex. Similarly, motion direction discrimination learning is transferable between first- and second-order motion signals. These results suggest that VPL can take place at a conceptual level and generalize to stimuli with different physical properties. Our findings thus reconcile perceptual and object learning into a unified framework.
  
  
  CONCLUSIONS
  Training in object recognition can produce a learning effect that is applicable to new viewing conditions or even to new objects with different physical properties. However, perceptual learning has long been regarded as a low-level form of learning because of its specificity to the trained stimulus conditions. Here we demonstrate with new training tactics that visual perceptual learning is completely transferrable between distinct physical stimuli. This finding indicates that perceptual learning also operates at a conceptual level in a stimulus-invariant manner.
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China, and Department of Psychology, IDG/McGovern Institute for Brain Research, and Peking-Tsinghua Center for Life Sciences, Peking University 100871 Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China, and.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Psychology, IDG/McGovern Institute for Brain Research, and Peking-Tsinghua Center for Life Sciences, Peking University 100871 Beijing, China.
authors.forename: Jun-Yun
authors.initials: JY
authors.lastname: Zhang
authors.affiliation: Department of Psychology, IDG/McGovern Institute for Brain Research, and Peking-Tsinghua Center for Life Sciences, Peking University 100871 Beijing, China.
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Xie
authors.affiliation: Department of Psychology, IDG/McGovern Institute for Brain Research, and Peking-Tsinghua Center for Life Sciences, Peking University 100871 Beijing, China.
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China, and.
authors.forename: Shu-Han
authors.initials: SH
authors.lastname: Luo
authors.affiliation: Department of Psychology, IDG/McGovern Institute for Brain Research, and Peking-Tsinghua Center for Life Sciences, Peking University 100871 Beijing, China yucong@pku.edu.cn liwu@bnu.edu.cn.
authors.forename: Cong
authors.initials: C
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China, and yucong@pku.edu.cn liwu@bnu.edu.cn.
authors.forename: Wu
authors.initials: W
authors.lastname: Li
mesh_terms: D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D009949:Orientation / Q000502:physiology; D010465:Perception / Q000502:physiology*; D010775:Photic Stimulation; D065853:Spatial Learning; D014163:Transfer, Psychology / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult
keywords: motion direction; orientation; perceptual learning; transfer