, Volume 61, Issue 6, pp 1009-1023

Top-down and bottom-up attentional control: On the nature of interference from a salient distractor


In two experiments using spatial probes, we measured the temporal and spatial interactions between top-down control of attention and bottom-up interference from a salient distractor in visual search. The subjects searched for a square among circles, ignoring color. Probe response times showed that a color singleton distractor could draw attention to its location in the early stage of visual processing (before a 100-msec stimulus onset asynchrony [SOA]), but only when the color singleton distractor was located far from the target. Apparently the bottom-up activation of the singleton distractor’s location is affected early on by local interactions with nearby stimulus locations. Moreover, probe results showed that a singleton distractor did not receive attention after extended practice. These results suggest that top-down control of attention is possible at an early stage of visual processing. In the long-SOA condition (150-msec SOA), spatial attention selected the target location over distractor locations, and this tendency occurred with or without extended practice.

Data from Experiment 1 were presented at the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO), April, 1996, Fort Lauderdale, FL. This work was supported in part by NEI Grant EY 08126 to the Vanderbilt Vision Research Center.
—Accepted by previous editor: Myron L. Braunstein