Measuring conscious perception interferes with the allocation of attention to distractors.

A topic of interest in the attention capture literature is the interaction between attention and conscious perception. Many studies have examined whether conscious perception of an irrelevant distracting stimulus is necessary for it to capture attention. One approach involves using measures that require subjects to rate their perceived clarity of a distractor on every trial. The purpose of this study was to determine whether the assessment of conscious perception of the distractor using such measures impacts the allocation of attention to the distractor. We investigated whether measuring conscious perception of a distractor increases its relevance to the observer, causing attention to be allocated to the distractor voluntarily rather than captured involuntarily. We examined this possibility in four experiments in which subjects completed a Rapid Serial Visual Presentation (RSVP) task. To determine whether attention is allocated voluntarily to the distractor or captured by it, we measured two effects indicative of attention capture, the contingent capture effect and a spatial distance effect. The results suggest that when conscious perception was measured distractors captured attention irrespective of whether the distractor and target colour matched. However, when conscious perception was not being measured a robust contingent capture effect was consistently observed. Although the effect of the spatial distance manipulation was mixed, we consistently observed a larger attentional blink by target-matching distractors presented at a location far from the focally attended region when conscious perception was measured than when it was not. Thus, we concluded that measuring conscious perception of a distractor interferes with the allocation of attention to the distractor by causing it to be voluntarily attended as though it were task relevant, masking the hallmarks observed when attention is captured. The present findings suggest that previous claims made about the interaction between conscious perception and attention may be premature, necessitating either development of a new measure, or adjustments to existing measures.