title: Orientation-cue invariant population responses to contrast-modulated and phase-reversed contour stimuli in macaque V1 and V2.
abstract: Visual scenes can be readily decomposed into a variety of oriented components, the processing of which is vital for object segregation and recognition. In primate V1 and V2, most neurons have small spatio-temporal receptive fields responding selectively to oriented luminance contours (first order), while only a subgroup of neurons signal non-luminance defined contours (second order). So how is the orientation of second-order contours represented at the population level in macaque V1 and V2? Here we compared the population responses in macaque V1 and V2 to two types of second-order contour stimuli generated either by modulation of contrast or phase reversal with those to first-order contour stimuli. Using intrinsic signal optical imaging, we found that the orientation of second-order contour stimuli was represented invariantly in the orientation columns of both macaque V1 and V2. A physiologically constrained spatio-temporal energy model of V1 and V2 neuronal populations could reproduce all the recorded population responses. These findings suggest that, at the population level, the primate early visual system processes the orientation of second-order contours initially through a linear spatio-temporal filter mechanism. Our results of population responses to different second-order contour stimuli support the idea that the orientation maps in primate V1 and V2 can be described as a spatial-temporal energy map.
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China; Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei, P. R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: An
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Gong
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Jiapeng
authors.initials: J
authors.lastname: Yin
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China; Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei, P. R. China.
authors.forename: Xian
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Yiliang
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei, P. R. China.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Faculty of Life Science, University of Manchester, Manchester, United Kingdom.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Toth
authors.affiliation: Faculty of Life Science, University of Manchester, Manchester, United Kingdom.
authors.forename: Ingo
authors.initials: I
authors.lastname: Schiessl
authors.affiliation: Faculty of Life Science, University of Manchester, Manchester, United Kingdom.
authors.forename: Niall
authors.initials: N
authors.lastname: McLoughlin
authors.affiliation: Institute of Neuroscience, State Key Laboratory of Neuroscience and Key Laboratory of Primate Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D000818:Animals; D001931:Brain Mapping; D015350:Contrast Sensitivity / Q000502:physiology*; D003463:Cues; D005556:Form Perception / Q000502:physiology*; D008029:Lighting; D008253:Macaca mulatta / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000166:cytology / Q000502:physiology; D061848:Optical Imaging; D010775:Photic Stimulation; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*