Transient attention equally reduces visual crowding in radial and tangential axes

Abstract

Crowding refers to the failure to identify a peripheral object due to its proximity to other objects (flankers). This phenomenon can lead to reading and object recognition impairments and is associated with macular degeneration, amblyopia, and dyslexia. Crucially, the maximal target–flanker spacing required for the crowding interference (critical spacing) increases with eccentricity. This spacing is also larger when target and flankers appear along the horizontal meridian (radial arrangement) than when the flankers appear above and below the target (tangential arrangement). This phenomenon is known as radial–tangential anisotropy. Previous studies have demonstrated that transient attention can reduce crowding interference; however, it is still unclear whether and how attention interacts with radial–tangential anisotropy. To address this issue, we manipulated transient attention by using a cue at either the target (valid) or the fixation (neutral) location, in both radial and tangential target–flanker arrangements. Results showed that critical spacing was larger in the radial than in the tangential arrangement and that cueing the target location improved performance and reduced the critical spacing for both radial and tangential arrangements to the same extent. Together, our findings suggest that transient spatial attention plays an essential role in crowding but not in radial–tangential anisotropy.

The role of spatial attention in crowding and feature binding

“…The present findings explain the inconsistent results of spatial attention investigations in crowding and attribute them to variations in the locus of attention. Consistent with the present study, previous studies using various cue and target types showed that cueing attention at the target location did not reduce crowding interference ( Scolari et al, 2007 ; Strasburger & Malania, 2013 ), whereas cueing attention at location inner to the target reduced crowding interference ( Grubb et al, 2013 ; Kewan-Khalayly et al, 2022 ; Yeshurun & Rashal, 2010 ).…”

“…Despite the compelling evidence for an attentional effect on spatial resolution, investigations of attentional manipulation in crowding have yielded mixed results. Some studies have shown that attention decreases critical spacing (i.e., the minimum spacing required for crowding) ( Grubb, Behrmann, Egan, Minshew, Heeger, & Carrasco, 2013 ; Kewan-Khalayly, Migó, & Yashar, 2022 ; Yeshurun & Rashal, 2010 ); however, other studies have failed to demonstrate an effect on crowding ( Scolari, Kohnen, Barton, & Awh, 2007 ; Strasburger, 2005 ). One possible reason for this inconsistency is that the locus of attention with respect to the target could have varied across these studies and therefore caused the attentional effect on crowding.…”

Effects of involuntary and voluntary attention on critical spacing of visual crowding

“…Our data set includes a large number of participants (21 that were included in the analyses presented here) and a substantial amount of data per subject (3,840 trials of the anticueing task). In comparison, recent studies of the effects of spatial attention on crowding (e.g., Yeshurun & Rashal, 2010 ; Albonico et al., 2018 ; Kewan-Khalayly, Migó, & Yashar, 2022 ) included 16 or fewer subjects per main experiment and 1,280 or fewer trials per subject. Our study therefore has high sensitivity for detecting possible cueing effects on RT and critical spacing.…”

“…There is much debate about how attention affects visual crowding in general and critical spacing in particular. Most studies of the effects of involuntary attention have found enhanced perceptual performance on crowding tasks, and some of these also reported significant effects of involuntary attention on critical spacing ( Yeshurun & Rashal, 2010 ; Rashal & Yeshurun, 2014 ; Kewan-Khalayly, Migó, & Yashar, 2022 ) while others did not ( Felisberti, Solomon, & Morgan, 2005 ; Scolari, Kohnen, Barton, & Awh, 2007 ). Yeshurun and Rashal (2010) hypothesized that they observed a significant decrease in critical spacing with involuntary attention while other investigators did not because their peripheral cue did not act as a forward mask on the processing of the subsequently presented target.…”

“…Visual crowding, the decrease in the ability to identify target objects in the periphery in the presence of similar flanking objects, is one of the strongest of these limitations ( Levi, 2008 ; Whitney & Levi, 2011 ). Previous research has shown that capture of involuntary attention with a peripheral cue improves performance ( Felisberti, Solomon, & Morgan, 2005 ; Scolari, Kohnen, Barton, & Awh, 2007 ) and decreases critical spacing (i.e., the minimum target/flanker spacing at which the target is correctly identified at a specified level of performance) on crowding tasks ( Yeshurun & Rashal, 2010 ; Rashal & Yeshurun, 2014 ; Kewan-Khalayly, Migó, & Yashar, 2022 ). Although these studies have characterized effects of involuntary attention on critical spacing in visual crowding, less is known about the effects of voluntary attention and how the effects of these two types of attention might be related.…”