Abstract
Since first reporting negative effects of short-SOA exogenous cues on a luminance-detection task, we have found that this phenomenon might be limited to situations with low levels of background illumination. Under bright florescent lighting, the uninformative cues produced a positive cuing effect (i.e., valid-cue trials produce faster responses); under dim halogen lighting, the same cues produced a negative effect (i.e., invalid-cue trials produce faster responses). These data suggest that perceptual factors play a critical role in what is purported to be an attentional paradigm. We hypothesize that participants opt for different strategies under different lighting conditions, given that a variety of percepts are available across trials. We further hypothesize that different levels of background illumination make some percepts more salient than the others. For example, under bright lighting, local “hot-spots” in illumination may dominate, which favors valid-cue trials; under dim lighting, apparent motion may be more salient, which favors invalid-cue trials. To test these ideas, we reduced the possible percepts that were available under both types of background lighting.