The role of perceptual load in inattentional blindness

Perceptual load theory offers a resolution to the long-standing early vs. late selection debate over whether task-irrelevant stimuli are perceived, suggesting that irrelevant perception depends upon the perceptual load of task-relevant processing. However, previous evidence for this theory has relied on RTs and neuroimaging. Here we tested the effects of load on conscious perception using the "inattentional blindness" paradigm. As predicted by load theory, awareness of a task-irrelevant stimulus was significantly reduced by higher perceptual load (with increased numbers of search items, or a harder discrimination vs. detection task). These results demonstrate that conscious perception of task-irrelevant stimuli critically depends upon the level of task-relevant perceptual load rather than intentions or expectations, thus enhancing the resolution to the early vs. late selection debate offered by the perceptual load theory.     

The role of probe trial distractors in the production/removal of the spatial negative priming effect

When a current (probe trial) target arises at a location formerly occupied by a distractor event (prime trial; ignored-repetition trial), its reaction time is slower than when it occurs at a previously empty location (control trial), revealing a spatial negative priming (SNP) effect. Here, we examined the influence of prime- and probe trial distractor identity similarity on the retrieval of the stored representations of prime trial processing (i.e., indexed by SNP production), in a context where the prevention of the SNP phenomenon had been motivated (via low probability of probe distractor presence—.25). Two results were important. One, the SNP effect was evident when the prime–probe distractor identities fully matched, but not when they partially or totally mismatched, showing a retrieval role for the probe distractor. Two, target-repeat trial latency facilitation showed the same pattern, indicating that representations of prime target and distractor processing are retrieved together, indicative of an episodic storage format. Since target identity remained fixed, the role of a matching probe distractor identity in SNP production was to presumably complete the triggering requirement (i.e., full event identity matching) for accessing the episodically stored representations.