Abstract
Increasing attention to one task typically impairs performance in a second task. However, the opposite can also occur: Encoding is facilitated for images that are presented at the same time that attention to an unrelated target detection task increases (“the attentional boost effect”; ABE). One potential explanation for the ABE is that the appearance of a target orients attention to the moment in time that the target appeared, facilitating perceptual processing of concurrently presented information (temporal orienting hypothesis). Accordingly, an image whose presentation overlaps in time with the presentation of the target will receive additional attention and processing resources. Alternatively, the ABE may result from temporal grouping (temporal grouping hypothesis). In previous experiments the images and targets always onset at the same time. Because common onset is a strong cue for temporal grouping, participants may have grouped the image and target into a single temporal entity. If this is the case, then increasing attention to the target should lead to enhanced processing of the entire temporal group, resulting in the ABE. To address these two hypotheses common onset and temporal overlap were manipulated. Experiment 1 demonstrated that the ABE occurs even when the target appears 100 ms later than the image. Experiments 2 and 3 showed that even though common onset is not necessary for the ABE, temporal overlap is. In these experiments the target could overlap with the image in time or it could appear over a mask 100 ms before or 100 ms after the image. Consistent with the temporal orienting hypothesis, the ABE was eliminated when the target did not overlap with the image in time. Based on these data, we suggest that perceptual processing of images presented with targets is enhanced because attention is oriented to the moment in time that the target appeared.
NIH and the University of Minnesota Institute for Marketing Research.