Attentional set interacts with perceptual load in visual search

• Published in: Psychonomic bulletin & review 2004-08, Vol.11 (4), p.697-702
• Main Authors: THEEUWES, Jan, KRAMER, Arthur F, BELOPOLSKY, Artem V
• Format: Article
• Language: English
• Subjects: Attention; Biological and medical sciences; Experiments; Fundamental and applied biological sciences. Psychology; Humans; Hypotheses; Perception; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Reaction Time; Sensory perception; Vision; Visual Perception; Visual task performance
• ISSN: 1069-9384; 1531-5320
• DOI: 10.3758/BF03196622

In the present study, we examined the hypothesis that perceptual load is the primary factor that determines the efficiency of attentional selection. Participants performed a visual search task under conditions of high- and low-load. In line with the perceptual load hypothesis, presenting conditions of high- and low-load in separate blocks of trials resulted in processing of to-be-ignored stimuli only in the low-load condition (Experiment 1). However when high- and low-load conditions were randomly mixed in blocks of trials, the participants showed processing of to-be-ignored stimuli in both conditions, suggesting that high perceptual load is not necessarily sufficient to obtain perceptual selectivity (Experiment 2). An analysis of intertrial transition effects showed that on high-load trials, processing of to-be-ignored stimuli occurred only when the previous trial was a low-load trial. The results suggest that low perceptual load can engender broad attentional processing. On the other hand, when a high-load trial was preceded by another high-load trial, little processing of task-irrelevant stimuli was observed. The present results are discussed in terms of the interaction between expectancies and bottom-up factors in the efficiency of attentional selection.