Proactive suppression can be applied to multiple salient distractors in visual search.

Abstract

There is a growing body of research demonstrating that the capture of attention by a single salient distractor can be prevented via proactive suppression. In real-world contexts, there are often several distracting events that compete for attention, but it is entirely unknown whether multiple objects can be suppressed concurrently. We used behavioral and electrophysiological measures to investigate the existence and time course of multiple-item suppression. We employed search displays that contained either one or two uniquely colored distractors that differed in their salience (S+ and S−), or no such distractors. Search performance improved with the number of salient distractors, indicating that the suppression of multiple items reduced the effective display set size. This was also the case when the target color was no longer fully predictable, ruling out an alternative explanation in terms of attentional guidance by target templates. In an experiment where S+ and S− always appeared together in the same display, the P D component (a marker of proactive suppression) was triggered exclusively by the more salient distractor (S+), indicative of single-item suppression. However, when displays with one or both salient distractors were intermixed, a reliable P D component was also triggered by S−, even when it was accompanied by S+ in the same display. These results show that multiple concurrent salient signals can be proactively inhibited. They demonstrate that signal suppression processes can be adaptively employed to counteract visual distraction at different locations, in order to facilitate the attentional selection of relevant objects in crowded visual environments. Public Significance StatementThis study shows that humans are capable of suppressing multiple salient but irrelevant visual items simultaneously. This highlights the flexibility of inhibitory mechanisms in selective attention. We provide both behavioral and electrophysiological evidence of multiple distractor suppression.

Proactive suppression is an implicit process that cannot be summoned on demand.

“…As indicated above, reactive suppression seems especially likely when the P D occurs in a late time window relative to the one (starting at 100 ms) reported by Gaspelin and Luck (see also Drisdelle & Eimer, 2023). A “late” P D in response to a color singleton is often reported when the target is itself a shape singleton.…”

“…This "late" P D component is often interpreted as a suppressive process involved in terminating attentional allocation to a stimulus…In short, the P D component can have a variable latency… This is important to consider when interpreting this component. (p. 1696) As indicated above, reactive suppression seems especially likely when the P D occurs in a late time window relative to the one (starting at 100 ms) reported by Gaspelin and Luck (see also Drisdelle & Eimer, 2023). A "late" P D in response to a color singleton is often reported when the target is itself a shape singleton.…”

“…The important contrast between proactive suppression and reactive suppression can also be seen in electrophysiological data. The P D could indicate the existence of proactive suppression (e.g., Drisdelle & Eimer, 2023; Gaspelin & Luck, 2018b), but it could sometimes indicate reactive suppression as well. As indicated in the recent review of the P D by Gaspelin et al (2023),…”

“…Hauck et al (2023) noted that although the P D might sometimes reflect reactive suppression it can, under the right conditions, also indicate proactive suppression. We propose that this proactive suppression interpretation of the P D is especially plausible when (a) the task does not promote singleton detection mode, (b) distractor presence costs are absent or even reversed (e.g., Gaspelin & Luck, 2018b), and (c) the P D occurs in an earlier time window (e.g., 100-200 ms in Drisdelle & Eimer, 2023;Gaspelin & Luck, 2018b).…”

Top-down suppression of negative features applies flexibly contingent on visual search goals

“…For instance, features maintained in working memory elicit greater attentional capture if reliably associated with a search target instead of with a distractor (Carlisle & Woodman, 2019 ; Kiyonaga et al, 2012 ; Olivers & Eimer, 2011 ). Furthermore, the processing of visual input corresponding to working-memory content might not always be enhanced, but instead also sometimes suppressed based on an observer’s current search goals (Drisdelle & Eimer, 2023 ; Kerzel & Huynh Cong, 2022 ; for reviews, see Carlisle, 2022 ; Noonan et al, 2018 ; van Moorselaar & Slagter, 2020 ).…”