ABSTRACT
A critical aspect of early visual processes is to extract shape data for matching against memory representations for recognition. Many theories of recognition assume that this is being done on luminance information. However, studies in psychophysics have revealed that color is being used by many low-level visual modules such as motion, stereopsis, texture, and 2D shapes. Should color really be discarded from theories of recognition? In this paper, we present two studies which seek to understand the role of chromatic information for the recognition of real scene pictures. We used three versions of scene pictures (gray-levels, normally colored and abnormally colored) coming from two broad classes of categories. In the first category, color was diagnostic of the category (e.g., beach, forest and valley). In the second category color was not diagnostic (e.g., city, road and room). Results revealed that chromatic information is being registered and facilitates recognition even after a 30 ms exposure to the scene stimuli. Similar results were recorded with exposures of 120 ms. However, influences of color on speeded categorizations were only observed with the color-diagnostic categories. No influence of color was observed with the other categories.
