P_D components and distractor inhibition in visual search: New evidence for the signal suppression hypothesis

Abstract

The hypothesis that salient distractors in visual search are actively suppressed is supported by the fact that these objects elicit P D components believed to be associated with inhibition. This account was challenged by researchers who found that a P D to lateral color singleton distractors was followed by a contralateral negativity, which How to cite this article: Drisdelle BL, Eimer M. P D components and distractor inhibition in visual search: New evidence for the signal suppression hypothesis.

What the flip? What the P-N flip can tell us about proactive suppression

“…Extending the P-N flip simulation onto other related effects. (A) Absence of search targets selectively reduces the N component in the simulation, consistent with Drisdelle & Eimer (2021). (B) Increasing the set size changes a number of parameters, including target salience, singleton salience, and inter-item distance.…”

“…In this paper, we described a new account for the P-N flip in fixed feature search (Drisdelle & Eimer, 2021;Kerzel & Burra, 2020) through a combination of proactive featural 25 WHAT THE FLIP suppression and reactive suppression implemented with RAGNAROC. We suggest that as the consistent feature of the singleton distractor is proactively suppressed, the singleton distractor is essentially ignored by the attentional system.…”

“… 1 Preventive suppression may also manifest as active suppression, where suppression is said to operate on early saliency signals but only after display onset (Sawaki & Luck, 2010). We note here that this type of salience-based active suppression is sometimes discussed as a mechanism of “proactive” suppression (Drisdelle & Eimer, 2021; Gaspelin & Luck, 2019; Luck et al, 2021). However, our view is that a suppression process should be classified as “proactive” only if the inhibition process occurs before display onset.…”

“…It should be noted here that a few studies have inspected the EEG waveforms with respect to a consistent-color distractor positioned contralateral to an empty space, but a Pd was observed (Hickey et al, 2009; Hilimire et al, 2012). However, this Pd occurred slightly later (onset at ∼220ms) than the P component in the P-N flip (∼185ms in Kerzel & Burra, 2020; ∼110ms in Drisdelle & Eimer, 2021) and was sometimes preceded by a N2pc; a distractor-present RT cost was also observed in some cases (Hilimire et al, 2012). These observations suggest that participants may not have employed proactive suppression, despite it having a consistent color.…”

“…Although participants were able to utilize this spatial regularity to their advantage, as they were substantially faster to respond to the target compared to the “unfocused” condition (where the target could appear at any of the four locations), the P-N flip was reliably observed in both conditions – meaning that a lateral-first serial search strategy cannot completely explain the P-N flip. Drisdelle & Eimer (2021) in turn proposed that the ERPs were two successive Pd components – the first one reflecting suppression of the singleton distractor, and the second one reflecting suppression of the lateral nonsingleton distractor. They further suggested that the suppression of the singleton distractor occurred earlier because of its superior salience.…”