Color signals in area MT of the macaque monkey.
The relationship between the neural processing of color and motion information has been a contentious issue in visual neuroscience. We examined this relationship directly by measuring neural responses to isoluminant S cone signals in extrastriate area MT of the macaque monkey. S cone stimuli produced robust, direction-selective responses at most recording sites, indicating that color signals are present in MT. While these responses were unequivocal, S cone contrast sensitivity was, on average, 1.0-1.3 log units lower than luminance contrast sensitivity. The presence of S cone responses and the relative sensitivity of MT neurons to S cone and luminance signals agree with functional magnetic resonance imaging (fMRI) measurements in human MT+. The results are consistent with the hypothesis that color signals in MT influence behavior in speed judgment tasks.
Seidemann
E
E
Howard Hughes Medical Institute, Department of Neurobiology, Stanford University, California 94305, USA.
Poirson
A B
AB
Wandell
B A
BA
Newsome
W T
WT
D000221:Adaptation, Ocular / Q000502:physiology; D000818:Animals; D002138:Calibration; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D004594:Electrophysiology; D005403:Fixation, Ocular / Q000502:physiology; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging; D008839:Microelectrodes; D009039:Motion Perception / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology*