title: Search for color 'center(s)' in macaque visual cortex.
abstract: It is often stated that color is selectively processed in cortical area V4, in both macaques and humans. However most recent data suggests that color is instead processed in region(s) antero-ventral to V4. Here we tested these two hypotheses in macaque visual cortex, where 'V4' was originally defined, and first described as color selective. Activity produced by equiluminant color-varying (versus luminance-varying) gratings was measured using double-label deoxyglucose in awake fixating macaques, in multiple areas of flattened visual cortex. Much of cortex was activated near-equally by both color- and luminance-varying stimuli. In remaining cortical regions, discrete color-biased columns were found in many cortical visual areas, whereas luminance-biased activity was found in only a few specific regions (V1 layer 4B and area MT). Consistent with a recent hypothesis, V4 was not uniquely specialized for color processing, but areas located antero-ventral to V4 (in/near TEO and anterior TE) showed more color-biased activity.
authors.affiliation: Nuclear Magnetic Resonance Center, Massachusetts General Hospital and Department of Radiology, Harvard Medical School, Boston, MA 02115, USA. tootell@nmr.mgh.harvard.edu
authors.forename: Roger B H
authors.initials: RB
authors.lastname: Tootell
authors.forename: Koen
authors.initials: K
authors.lastname: Nelissen
authors.forename: Wim
authors.initials: W
authors.lastname: Vanduffel
authors.forename: Guy A
authors.initials: GA
authors.lastname: Orban
mesh_terms: D000818:Animals; D000963:Antimetabolites; D001345:Autoradiography; D001931:Brain Mapping; D003118:Color Perception / Q000502:physiology*; D003216:Conditioning, Operant / Q000187:drug effects; D003847:Deoxyglucose; D003576:Electron Transport Complex IV / Q000378:metabolism; D005074:Evoked Potentials, Visual / Q000502:physiology; D005403:Fixation, Ocular / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D008253:Macaca mulatta; D008297:Male; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology*
chemical_list: D000963:Antimetabolites; D003847:Deoxyglucose; D003576:Electron Transport Complex IV