Attentional effects on preattentive vision: Spatial precues affect the detection of simple features

Most accounts of visual perception hold that the detection of primitive fea tures occurs preattentively, in parallel across the visual field. Evidence that preattentive vision operates without attentional limitations comes fro m visual search tasks in which the detection of the presence or absence of a primitive feature is independent of the number of stimuli in a display. I f the detection of primitive features occurs preattentively, in parallel an d without capacity limitations, then it should not matter where attention i s located in the visual held. The present study shows that even though the detection of a red element in an array of gray elements occurred in paralle l without capacity limitations, the allocation of attention did have a larg e effect on search performance. If attention was directed to a particular r egion of the display and the target feature was presented elsewhere, respon se latencies increased. Results indicate that the classic view of preattent ive vision requires revision.