An fMRI version of the Farnsworth-Munsell 100-Hue test reveals multiple color-selective areas in human ventral occipitotemporal cortex

Studies of patients with cerebral achromatopsia have suggested that ventral occipitotemporal cortex is important for color perception. We created a fu nctional magnetic resonance imaging (fMRI) version of a clinical test commo nly used to assess achromatopsia, the Farnsworth-Munsell 100-Hue test. The test required normal subjects to use color information in the visual stimul us to perform a color sequencing task. A modification of the test requiring ordering by luminance was used as a control task. Subjects were also image d as they passively viewed colored stimuli. A limited number of areas respo nded more to chromatic than achromatic stimulation, including primary visua l cortex. Most color-selective activity was concentrated in ventral occipit otemporal cortex. Several areas in ventral cortex were identified. The most posterior, located in posterior fusiform gyrus, corresponded to the area a ctivated by passive viewing of colored stimuli. More anterior and medial co lor-selective areas were located in the collateral sulcus and fusiform gyru s. These more anterior areas were not identified in previous imaging studie s which used passive viewing of colored stimuli, and were most active in ou r study when visual color information was behaviorally relevant, suggesting that attention influences activity in color-selective areas, The fMRI vers ion of the Farnsworth-Munsell test may be useful in the study of achromatop sia.