Limitations on the parallel guidance of visual search: color x color and orientation x orientation conjunctions.
In visual search for a conjunction it is much more difficult to search for the conjunction of 2 colors or 2 orientations than for Color x Orientation or Color x Shape conjunctions. The result is not limited to particular colors or shapes. Two colors cannot occupy the same spatial location in Color x Color searches. However, Experiments 6 and 7 show that Color x Shape searches remain efficient even if the color and shape are spatially separated. Our guided search model suggests that in searches for Color x Shape, a parallel color module can guide attention toward the correct color, whereas the shape module guides attention toward the correct shape. Together these 2 sources of guidance lead attention to the target. However, if a target is red and green among red-blue and green-blue distractors, it is not possible to guide search independently toward red items and green items or away from all blue items.
Wolfe
J M
JM
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139.
Yu
K P
KP
Stewart
M I
MI
Shorter
A D
AD
Friedman-Hill
S R
SR
Cave
K R
KR
D000328:Adult; D001288:Attention; D003118:Color Perception; D006801:Humans; D009949:Orientation; D010364:Pattern Recognition, Visual; D010470:Perceptual Masking; D011601:Psychophysics