Abstract
Several theories of perception suggest that changes in task context (e.g., a stoplight changes from green to yellow) produce a brief increase in perceptual processing of the surrounding environment. In line with this proposal, we recently reported a phenomenon in which the infrequent appearance of white target squares in a stream of black distractor squares facilitated encoding of concurrently presented background scenes and faces. This “Attentional Boost Effect” (ABE) occurs in spite of the potential for target detection to interfere with encoding background information. Instead, these data suggest that increased attention to one task facilitates encoding in a second task. However, direct evidence for enhanced perceptual processing is still lacking because subsequent memory, rather than perceptual processing was measured. Two experiments were conducted to determine whether the ABE reflects enhanced perceptual processing. If the ABE is due to enhanced perceptual processing then it should be easier to perceive stimuli that are briefly presented when targets appear. In Experiment 1, participants were asked to report the gender of a single upright face presented briefly (100ms) in a stream of inverted faces. They were also asked to monitor a colored border around the faces and press the spacebar whenever the border was blue (20% of the borders were blue). If target detection enhances perceptual processing of other, concurrently presented items, then gender discrimination should be better for faces with blue borders than for other faces. The data confirmed this hypothesis. Experiment 2 confirmed that memory for faces presented with targets is enhanced even when the faces were paired with targets only once. Therefore, memory enhancements associated with the ABE were not due to multiple exposures of the background item with the targets. We conclude that the ABE reflects enhanced perceptual processing of background information in response to the appearance of infrequent targets.
Funding provided by the University of Minnesota Institute for Marketing Research.