The visual system has emerged as a premier model for understanding information processing by neurons. Within vision, the submodality of color provides a particularly attractive experimental platform: we know a tremendous amount about the phenomenology of color perception and can explain some aspects of color perception, quantitatively and with high precision, by well- understood physiological processes. As a result of this progress, we can quickly and accurately diagnose many distinct forms of color blindness and can build devices that render colors accurately. On the other hand, surprising holes in our knowledge remain. The proposed research will fill this hole in our knowledge by determining where the temporal bottlenecks for detection and appearance reside. Three specific aims are planned: 1) Electrophysiological and modeling to determine where in the visual system luminance signaling is limited. 2) Electrophysiological and modeling to determine where in the visual system red- green chromatic signaling is limited. 3) Comparison of stimulus categories as classified by monkeys and by their component neurons to determine whether the dynamics of neuronal signals are responsible for changes in stimulus appearance as a function of temporal frequency. The proposed experiments will extend our knowledge toward an understanding of the principles that give rise to perception and its disorders. Such an understanding promises to provide the means to promote recovery of visual function following trauma or neurological disease.