Feature-based attention modulates feedforward visual processing.
It is widely believed that attention selects locations at an earlier stage than it selects nonspatial features, but this has been tested only under conditions of minimal competition. We found that, when competition was increased, color-based attention was able to influence the feedforward flow of information in humans within 100 ms of stimulus onset, even for stimuli presented at unattended locations. Thus, color-based attention can operate as early as, and independently from, spatial attention.
Zhang
Weiwei
W
Center for Mind and Brain, University of California Davis, 267 Cousteau Place, Davis, California 95618, USA. wwzhang@ucdavis.edu
Luck
Steven J
SJ
D001288:Attention / Q000502:physiology*; D003116:Color; D055253:Color Vision / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology; D005074:Evoked Potentials, Visual; D006801:Humans; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology; D013997:Time Factors; D014795:Visual Pathways / Q000502:physiology*