How fast can you change your mind? The speed of top-down guidance in visual search.
Most laboratory visual search tasks involve many searches for the same target, while in the real world we typically change our target with each search (e.g. find the coffee cup, then the sugar). How quickly can the visual system be reconfigured to search for a new target? Here observers searched for targets specified by cues presented at different SOAs relative to the search stimulus. Search for different targets on each trial was compared to search for the same target over a block of trials. Experiments 1 and 2 showed that an exact picture cue acts within 200 ms to make varied target conjunction search as fast and efficient as blocked conjunction search. Word cues were slower and never as effective. Experiment 3 replicated this result with a task that required top-down information about target identity. Experiment 4 showed that the effects of an exact picture cue were not mandatory. Experiments 5 and 6 used pictures of real objects to cue targets by category level.
Wolfe
Jeremy M
JM
Brigham and Women's Hospital, and Visual Attention Lab, Harvard Medical School, Cambridge, MA 02139, USA. wolfe@search.bwh.harvard.edu
Horowitz
Todd S
TS
Kenner
Naomi
N
Hyle
Megan
M
Vasan
Nina
N
D003071:Cognition; D003463:Cues; D006801:Humans; D007802:Language; D007858:Learning; D008960:Models, Psychological; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time; D013997:Time Factors; D014796:Visual Perception