Abstract
Observers conduct visual search more efficiently when the same spatial context is repeated (contextual cueing effect). The present experiment examined the time course of contextual guidance of attention by using a masking procedure. In the training phase, participants searched for a rotated-T target among rotated-L distractors and indicated the orientation of the target as quickly and accurately as possible. Thirty-two layouts were repeatedly presented 20 times. In the following test phase, the repeated and newly generated layouts were presented for 10 ms and then masked. The stimulus onset asynchrony between display and mask was varied. Participants made a two alternative forced choice to indicate the orientation of the target. The contextual cueing effect was evaluated as accuracy of performance in the test phase. The contextual cueing effect learned in the training phase was successfully transferred to the test phase. The contextual effect was evident with stimulus onset asynchrony as short as 150 ms. These results suggest that contextual guidance of attention emerges at early stages of visual processing, possibly involving a feed-forward, rather than iterative, processes.
This work was supported by Japan Society for the Promotion of Science.