C-01 An examination of characteristic of bottom-up processing in featuredefined multiple targets search task

Abstract

Three experiments examined the effect of top-down information on reduction of bottom-up activity in modified visual feature search tasks: target detection, target discrimination, and homogeneity judgement tasks. Efficiency of bottom-up information is manipulated by varying the number of targets in a display. Results showed that search time for targets was influenced by the number of targets, suggesting that a singleton is not a useful bottom-up source for visual search. Search time was changed as a function of tasks. This suggests that top-down processing is also involved and that weighting of it depends on the task.