Integration of colour, motion, orientation, and spatial frequency in visual search.
Response times (RTs) in visual search were measured with either a single target specified by colour, motion, spatial frequency, or orientation alone, or specified by pairwise conjunctions of these features, or by presenting double targets, each specified by a separate feature. First, for all feature combinations, except for motion-colour, RTs were faster when double features were used to specify a single target than when they specified separate targets, implying location-specific redundancy gains predicted by coactivation on a common location-specific map. Second, coactivation, as revealed by race-model violations, occurred for all double-feature single-target conditions except the motion-colour and colour-orientation combinations. No violations occurred in double-target conditions. Taken together, these results are accounted for by well-known feature-specific sensitivities of cortical V1 cells and provide further evidence for a V1 locus of redundancy gain in visual search.
Poom
Leo
L
Department of Psychology, Box 1225, Uppsala University, S-751 42 Uppsala, Sweden. leo.poom@psyk.uu.se
D000328:Adult; D003118:Color Perception / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D008959:Models, Neurological; D008960:Models, Psychological; D009039:Motion Perception / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D011930:Reaction Time / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology; D055815:Young Adult