Does attentional suppression occur at the level of perception or decision-making? Evidence from Gaspelin et al.’s (2015) probe letter task

Abstract

Visual attention is often inadvertently captured by salient stimuli. It was suggested that it is possible to prevent attentional capture in some search tasks by suppressing salient stimuli below baseline. Evidence for attentional suppression comes from a probe task that was interleaved with the main search task. In the probe task of Gaspelin et al. (Psychol Sci 26(11):1740–1750, 2015. https://doi.org/10.1177/0956797615597913), letters were shown on the stimuli of the search display and participants had to identify as many letters as possible. Performance was found to be worse for letters shown on the distractor compared to non-salient non-target stimuli, suggesting that distractor processing was suppressed below baseline. However, it is unclear whether suppression occurred at the level of perception or decision-making because participants may have reported letters on the distractor less frequently than letters on nontargets. This decision-level bias may have degraded performance for letters on distractor compared to nontarget stimuli without changing perception. After replicating the original findings, we conducted two experiments where we avoided report bias by cueing only a single letter for report. We found that the difference between distractor and nontarget stimuli was strongly reduced, suggesting that decision-level processes contribute to attentional suppression. In contrast, the difference between target and non-target stimuli was unchanged, suggesting that it reflected perceptual-level enhancement of the target stimuli.

Global enhancement of target color—not proactive suppression—explains attentional deployment during visual search.

“…While this eliminates the effect of attentional associations from the search task, it also unbalances the frequency of the presentation of different colors, which could have unexpected effects on attention. Second, the Chang and Egeth probe task uses cued report of a single item in place of the classic paradigm's free report task, meaning that it may index distinct mechanisms of attention or post-attentional biases (Kerzel & Renaud, 2022). Ultimately, our findings and those of studies using the Chang and Egeth design are consistent in showing that featural enhancement of nontarget items is a significant factor in visual search tasks, which can be confounded with distractor suppression if not accounted for.…”

“…A notable difference between these four studies and the classic capture-probe task is that the former used cued report of a single probe, rather than the free recall task of the original. Recently, Kerzel and Renaud (2022) compared the effects of these probe task types, finding that they likely tap different mechanisms of perceptual versus decisional suppression; thus, it is unclear how comparable the Chang and Egeth version of the capture-probe task is with the original, in terms of attentional suppression. Nevertheless, a consistent implication of these four studies is that feature enhancement affects processing of nontarget, nonsingleton items in visual search tasks.…”

Visual Distraction’s “Silver Lining”: Distractor Suppression Boosts Attention to Competing Stimuli

“…It is also worth noting that recent results have suggested that probe tasks similar to the one used here may overestimate the extent to which the singleton distractor is suppressed. Kerzel and Renaud (2023) have shown that at least a portion of the reduction in the probe letter report rate for the singleton distractor can be attributed to a decision-level bias (as opposed to perceptual suppression) against reporting letters on the distractor. Conversely, if such a bias is sensitive to perceptual grouping effects similar to those that have been reported (e.g., Egly et al, 1994), then the bias might be expected to also reduce the letter report rate for non-singleton elements that are grouped with the distractor-a result that is contrary to the pattern that we found.…”

Swift attenuation of irrelevant features through feature consistency: Evidence from a capture-probe version of the contingent-capture protocol

“…This possibly points to a role of post-attentional influences of the inconsistently coloured non-matching cues on probe performance, for instance, a bias to start refreshing working memory representations of just seen and to-be-reported numbers at cued locations (cf. Kerzel & Renaud, 2023 ).…”