title: Perceptual learning modifies the functional specializations of visual cortical areas.
abstract: Training can improve performance of perceptual tasks. This phenomenon, known as perceptual learning, is strongest for the trained task and stimulus, leading to a widely accepted assumption that the associated neuronal plasticity is restricted to brain circuits that mediate performance of the trained task. Nevertheless, learning does transfer to other tasks and stimuli, implying the presence of more widespread plasticity. Here, we trained human subjects to discriminate the direction of coherent motion stimuli. The behavioral learning effect substantially transferred to noisy motion stimuli. We used transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms underlying the transfer of learning. The TMS experiment revealed dissociable, causal contributions of V3A (one of the visual areas in the extrastriate visual cortex) and MT+ (middle temporal/medial superior temporal cortex) to coherent and noisy motion processing. Surprisingly, the contribution of MT+ to noisy motion processing was replaced by V3A after perceptual training. The fMRI experiment complemented and corroborated the TMS finding. Multivariate pattern analysis showed that, before training, among visual cortical areas, coherent and noisy motion was decoded most accurately in V3A and MT+, respectively. After training, both kinds of motion were decoded most accurately in V3A. Our findings demonstrate that the effects of perceptual learning extend far beyond the retuning of specific neural populations for the trained stimuli. Learning could dramatically modify the inherent functional specializations of visual cortical areas and dynamically reweight their contributions to perceptual decisions based on their representational qualities. These neural changes might serve as the neural substrate for the transfer of perceptual learning.
authors.affiliation: Department of Psychology, Peking University, Beijing 100871, People's Republic of China; Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, People's Republic of China; Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing 100871, People's Republic of China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China; Peking University - International Data Group/McGovern Institute for Brain Research, Peking University, Beijing 100871, People's Republic of China;
authors.forename: Nihong
authors.initials: N
authors.lastname: Chen
authors.affiliation: Department of Psychology, Peking University, Beijing 100871, People's Republic of China; Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, People's Republic of China; Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing 100871, People's Republic of China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China; Peking University - International Data Group/McGovern Institute for Brain Research, Peking University, Beijing 100871, People's Republic of China;
authors.forename: Peng
authors.initials: P
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China;
authors.forename: Tiangang
authors.initials: T
authors.lastname: Zhou
authors.affiliation: School of Optometry and Vision Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada; School of Optometry and Vision Science, University of Auckland, Auckland 92019, New Zealand.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Thompson
authors.affiliation: Department of Psychology, Peking University, Beijing 100871, People's Republic of China; Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, People's Republic of China; Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing 100871, People's Republic of China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China; Peking University - International Data Group/McGovern Institute for Brain Research, Peking University, Beijing 100871, People's Republic of China; ffang@pku.edu.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007858:Learning; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009473:Neuronal Plasticity; D011597:Psychomotor Performance; D011601:Psychophysics; D050781:Transcranial Magnetic Stimulation; D014793:Visual Cortex / Q000502:physiology*
keywords: functional magnetic resonance imaging; motion; perceptual learning; psychophysics; transcranial magnetic stimulation