Can enhancement and suppression concurrently guide attention? An assessment at the individual level

Abstract

Background: Although people can pay attention to targets while ignoring distractors, previous research suggests that target enhancement and distractor suppression work separately and independently. Here, we sought to replicate previous findings and re-establish their independence. Methods: We employed an internet-based psychological experiment. We presented participants with a visual search task in which they searched for a specified shape with or without a singleton. We replicated the singleton-presence benefit in search performance, but this effect was limited to cases where the target color was fixed across all trials. In a randomly intermixed probe task (30% of all trials), the participants searched for a letter among colored probes; we used this task to assess how far attention was separately allocated toward the target or distractor dimensions. Results: We found a negative correlation between target enhancement and distractor suppression, indicating that the participants who paid closer attention to target features ignored distractor features less effectively and vice versa. Averaged data showed no benefit from target color or cost from distractor color, possibly because of the substantial differences in strategy across participants. Conclusions: These results suggest that target enhancement and distractor suppression guide attention in mutually dependent ways and that the relative contribution of these components depends on the participants’ search strategy.

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

“…Our conclusions are seemingly at odds with recent studies investigating both distractor suppression and target enhancement in a similar search and probe task (Chang & Egeth, 2019, 2021Hamblin-Frohman et al, 2022). There, attentional enhancement for target features has consistently been found, along with evidence for suppression of singleton distractor features (but see Kawashima & Amano, 2022). Two methodological variations in the Chang and Egeth design could account for the differences, and suggest caution in comparing their findings with those using the classic capture-probe paradigm.…”

“…In these studies, separable effects of target enhancement and distractor suppression on probe performance were investigated by explicitly comparing probe item processing against nonsingleton probes appearing in “neutral” colors. The studies all showed large effects of facilitation by target features, and of suppression associated with singleton distractors, except for an online replication which did not find the suppression effect (Kawashima & Amano, 2022). 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.…”

“…In previous capture-probe studies, nonsingleton fillers have been treated as a neutral baseline because they were assumed to be task-irrelevant and to lack attentional facilitation or suppression. A series of recent studies using a similar dual-task design developed by Chang and Egeth (2019, 2021), Hamblin-Frohman et al (2022), and Kawashima and Amano (2022) have challenged this assumption. In these studies, separable effects of target enhancement and distractor suppression on probe performance were investigated by explicitly comparing probe item processing against nonsingleton probes appearing in “neutral” colors.…”

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

“…Chang and Egeth (2019) used this approach in a variant of the probe paradigm in which participants occasionally switched from looking for a shape in the search trials to looking for the target letter A or B amongst three other letters in the probe trials. They found longer RTs when the target letter A or B was presented on the distractor color object rather than on a neutral color object (but see Kawashima & Amano, 2022). Hamblin-Frohman et al (2022) reported a similar effect when measuring eye fixations.…”