Interference and negative priming from ignored distractors: the role of selection difficulty.

The relation between distractor interference and negative priming from identical distractors was examined in two experiments. Subjects responded to a target letter, which was indicated by an adjacent bar marker, and attempted to ignore a distracting letter. On prime trials, distracting letters were either compatible or incompatible with the target, allowing for a measure of interference. On subsequent probe trials, previously ignored distractors were sometimes presented as targets, allowing for a measure of negative priming. Reducing the spatial separation between targets and distractors on the prime trial increased the magnitude of interference and negative priming, but these effects appeared to be independent of each other (Experiment 1). In Experiment 2, the prime target location was precued on some trials, but not on others. Precuing attenuated the magnitude of interference, but not that of negative priming effects. This pattern indicates that measures of negative priming and measures of distractor interference on the immediately preceding trial are independent. The results are discussed in terms of a selective inhibition model of selective attention.