Hierarchical Representation for Chromatic Processing across Macaque V1, V2, and V4.
The perception of color is an internal label for the inferred spectral reflectance of visible surfaces. To study how spectral representation is transformed through modular subsystems of successive cortical areas, we undertook simultaneous optical imaging of intrinsic signals in macaque V1, V2, and V4, supplemented by higher-resolution electrophysiology and two-photon imaging in awake macaques. We find a progressive evolution in the scale and precision of chromotopic maps, expressed by a uniform blob-like architecture of hue responses within each area. Two-photon imaging reveals enhanced hue-specific cell clustering in V2 compared with V1. A phenomenon of endspectral (red and blue) responses that is clear in V1, recedes in V2, and is virtually absent in V4. The increase in mid- and extra-spectral hue representations through V2 and V4 reflects the nature of hierarchical processing as higher areas read out locations in chromatic space from progressive integration of signals relayed by V1.
['Liu|Ye|Y|', 'Li|Ming|M|', 'Zhang|Xian|X|', 'Lu|Yiliang|Y|', 'Gong|Hongliang|H|', 'Yin|Jiapeng|J|', 'Chen|Zheyuan|Z|', 'Qian|Liling|L|', 'Yang|Yupeng|Y|', 'Andolina|Ian Max|IM|', 'Shipp|Stewart|S|', 'Mcloughlin|Niall|N|', 'Tang|Shiming|S|', 'Wang|Wei|W|']
D000818:Animals D001931:Brain Mapping D003118:Color Perception D005260:Female D008253:Macaca mulatta D008297:Male D009474:Neurons D010775:Photic Stimulation D014793:Visual Cortex D014795:Visual Pathways
macaque V1 V2 V4 2-photon calcium imaging color perception cortical hue representation intrinsic-signal optical imaging visual cortex