Abstract
Perception of the second of two targets (T2) embedded in a temporal stream of distractors is often impaired as compared with perception of the first target (T1), a phenomenon known as the attentional blink (AB). Explanations of the AB commonly ascribe the impairment to a conflict in postperceptual stages of processing. Here, the standard AB paradigm was manipulated to investigate the effect of the stimulus energy (the absolute value of the product of contrast and exposure duration) of the individual items (alphanumeric characters) in the rapid serial visual presentation (RSVP). In both experiments, all items in the RSVP were presented with a constant stimulus-onset asynchrony of 100 ms. In Experiment 1, the items were presented in black on a white background, and the duration of individual stimuli was either 30 ms (corresponding to an interstimulus interval of 70 ms) or 100 ms (corresponding to an ISI of 0 ms). In Experiment 2, the stimulus duration was kept constant at a value of 100 ms with zero ISI, but the luminance contrast of the stimulus items was varied between conditions (black on white vs. dark grey on light grey). In both experiments, the results showed strong effects of stimulus energy. T2 report accuracy showed superior performance in high-energy conditions (long exposure duration in Experiment 1 and high contrast in Experiment 2) compared with low-energy conditions (short exposure duration and low contrast). Additionally, calculations of blink magnitude using T1 report accuracy as baseline performance revealed a stronger blink in low-energy conditions compared with high-energy conditions. Thus, although most theories place the locus of the AB at a late stage of processing (e.g., consolidation in memory), mechanisms of early vision also contribute to the effect.
Meeting abstract presented at VSS 2012