Perceptual selectivity for color and form.
Three visual-search experiments tested whether the preattentive parallel stage can selectively guide the attentive stage to a particular known-to-be-relevant target feature. Subjects searched multielement displays for a salient green circle that had a unique form when surrounded by green nontarget squares or had a unique color when surrounded by red nontarget circles. In the distractor conditions, a salient item in the other dimension was present as well. As an extension of earlier findings (Theeuwes, 1991), the results showed that complete top-down selectivity toward a particular feature was not possible, not even after extended and consistent practice. The results reveal that selectivity depends on the relative discriminability of the stimulus dimensions: the presence of an irrelevant item with a unique color interferes with parallel search for a unique form, and vice versa.
Theeuwes
J
J
TNO Institute for Perception, Soesterberg, The Netherlands.
D000293:Adolescent; D000328:Adult; D003118:Color Perception / Q000502:physiology*; D004867:Equipment Design; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D008606:Mental Processes; D010470:Perceptual Masking