The role of spatial attention in crowding and feature binding

Abstract

Crowding refers to the failure to identify a peripheral object due to nearby objects (flankers). A hallmark of crowding is inner–outer asymmetry; that is, the outer flanker (more peripheral) produces stronger interference than the inner one. Here, by manipulating attention, we tested the predictions of two competing accounts: the attentional account, which predicts a positive attentional effect on the inner–outer asymmetry (i.e., attention to the outer flanker will increase asymmetry) and the receptive field size account, which predicts a negative attentional effect. In Experiment 1, observers estimated a Gabor target orientation. A peripheral pre-cue drew attention to one of three locations: target, inner flanker, or outer flanker. Probabilistic mixture modeling demonstrated asymmetry by showing that observers often misreported the outer-flanker orientation as the target. Interestingly, the outer cue led to a higher misreport rate of the outer flanker, and the inner cue led to a lower misreport rate of the outer flanker. Experiment 2 tested the effect of crowding and attention on incoherent object reports (i.e., binding errors, reporting the tilt of one presented item with the color of another item). In each trial, observers estimated both the tilt and color of the target. Attention merely increased coherent target reports, but not coherent flanker reports. The results suggest that the locus of spatial attention plays an essential role in crowding, as well as inner–outer asymmetry, and demonstrate that crowding and feature binding are closely related. However, our findings are inconsistent with the view that covert attention automatically binds features together.

Rapid assessment of peripheral visual crowding

“…An alternative explanation for the differences in crowding magnitudes between paradigms could be a difference in their spatial attentional demand. Previous research has indicated that attentional cues can influence crowding ( Grubb, 2013 ; Kewan-Khalayly and Yashar, 2022 ; Kewan-Khalayly et al, 2022 ). It is arguably easier and likely more effective to attend to the two possible target locations of the 2AFC paradigms compared to the multiple locations in the other paradigms.…”

Sparse spatial scaffolding for visual working memory

“…Though our star]ng point was different, our experimental manipula]ons resemble those in complementary research on the role of eccentricity and crowding in vision (e.g., [66][67][68][69][70][71][72][73][74] ) and visual working memory (e.g., [75][76][77] ). This literature has typically focused on other ques]ons, such as how visual resolu]on changes when moving from central to peripheral vision.…”

The impact of training on the inner–outer asymmetry in crowding

“…Researchers have been seeking effective ways to relieve crowding. Several studies have demonstrated that cueing of a crowded target location reduces the crowding effects ( Anton-Erxleben & Carrasco, 2013 ; Kewan-Khalayly, Migó, & Yashar, 2022 ; Kewan-Khalayly & Yashar, 2022 ; Talgar, Pelli, & Carrasco, 2004 ; Yeshurun & Carrasco, 1999 ), and modulating attentional allocation could affect inner–outer asymmetry ( Chakravarthi, Rubruck, Kipling, & Clarke, 2021 ; Kewan-Khalayly & Yashar, 2022 ; Kewan & Yashar, 2021 ; Petrov & Meleshkevich, 2011b ). However, the role of attentional modulation has still been controversial, as some studies have reported that it has little or even no effect on crowding ( Huckauf & Heller, 2002 ; Nazir, 1992 ; Scolari, Kohnen, Barton, & Awh, 2007 ; Wilkinson, Wilson, & Ellemberg, 1997 ).…”