Eyes on crowding: Crowding is preserved when responding by eye and similarly affects identity and position accuracy

Yildirim, Funda; Meyer, Vincent; Cornelissen, Frans W.

doi:10.1167/15.2.21

Cited by 12 publications

(16 citation statements)

References 48 publications

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“…Contrary to recent suggestions that crowding and saccades are closely linked (37)(38)(39), four aspects of our data lead us to reject an inextricable linkage between these processes. First, although crowding and saccades show similar patterns of variation, saccadic precision is worse in the lower visual field than in the upper-the opposite pattern not only to crowding, but also to a wide range of perceptual tasks (24,25).…”

Section: Discussioncontrasting

confidence: 99%

“…Because participants were required to both identify and make a saccade to a specified target, it was important that stimuli had both clearly defined features (for identification) and a clearly defined center (to direct saccades toward); saccades driven by identity alone (e.g., "saccade to the vertical stimulus") would make it difficult to separate identification errors from localization errors (39). Our clock stimuli, depicted in Fig.…”

Section: Methodsmentioning

confidence: 99%

“…Recent studies suggest that there may be a particularly strong link between these processes (37)(38)(39), despite the more general dissociation between perceptual and saccadic localization (40)(41)(42)(43) and their apparently distinct cortical routes (34). Our first aim was therefore to examine whether saccadic precision and crowding covary across the visual field by measuring the size of crowded interference zones and the precision of saccade landing positions ("saccade error zones") for the same stimuli in a range of visual-field locations.…”

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confidence: 99%

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Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision

Greenwood

Szinte

Sayim

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

115

152

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Visual sensitivity varies across the visual field in several characteristic ways. For example, sensitivity declines sharply in peripheral (vs. foveal) vision and is typically worse in the upper (vs. lower) visual field. These variations can affect processes ranging from acuity and crowding (the deleterious effect of clutter on object recognition) to the precision of saccadic eye movements. Here we examine whether these variations can be attributed to a common source within the visual system. We first compared the size of crowding zones with the precision of saccades using an oriented clock target and two adjacent flanker elements. We report that both saccade precision and crowded-target reports vary idiosyncratically across the visual field with a strong correlation across tasks for all participants. Nevertheless, both group-level and trial-by-trial analyses reveal dissociations that exclude a common representation for the two processes. We therefore compared crowding with two measures of spatial localization: Landolt-C gap resolution and three-dot bisection. Here we observe similar idiosyncratic variations with strong interparticipant correlations across tasks despite considerably finer precision. Hierarchical regression analyses further show that variations in spatial precision account for much of the variation in crowding, including the correlation between crowding and saccades. Altogether, we demonstrate that crowding, spatial localization, and saccadic precision show clear dissociations, indicative of independent spatial representations, whilst nonetheless sharing idiosyncratic variations in spatial topology. We propose that these topological idiosyncrasies are established early in the visual system and inherited throughout later stages to affect a range of higher-level representations.O ur sensitivity to visual stimuli varies substantially across the visual field with characteristic patterns that are evident across a wide range of tasks. Most notably, our ability to see fine detail decreases sharply as objects move into peripheral vision (1). These abilities are further disrupted by crowding, the impairment of object recognition in clutter, which also increases with eccentricity (2, 3). Both of these effects have been attributed to an overrepresentation of the fovea at the expense of peripheral vision, known as "cortical magnification" (4, 5), which has been observed in a range of retinotopically organized areas of the brain (6, 7). Here we ask whether other variations in visual sensitivity can similarly be attributed to topological principles within the visual system and consider whether these variations might share a common source.Variations across the visual field are particularly apparent with crowding, a process that presents the fundamental limitation on object recognition in peripheral vision (8). Crowding disrupts the recognition of a target object when flanker objects fall within a surrounding "interference zone." As well as increasing in size with eccentricity, these zones show an elliptical shap...

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Section: Discussioncontrasting

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision

Greenwood

Szinte

Sayim

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

115

152

View full text Add to dashboard Cite

show abstract

“…However, recent evidence of idiosyncratic patterns within these suggest that saccade control and visual crowding are linked through a common lower level spatial representation rather than being closely linked (Greenwood et al, 2017). This could then provide an explanation that sits with the perceptual organization of the target path into a larger Gestalt on the basis of pooling of lower level location information of individual targets, which, in turn, increases the positional uncertainty of individual targets and results in an increase in saccade landing position error found here (Yildirim, Meyer & Cornelissen, 2015).…”

Section: Discussionmentioning

confidence: 55%

The parallel programming of landing position in saccadic eye movement sequences

2020

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Saccadic eye movements occur in sequences, gathering new information about the visual environment to support successful task completion. Here, we examine the control of these saccadic sequences and specifically the extent to which the spatial aspects of the saccadic responses are programmed in parallel. We asked participants to saccade to a series of visual targets and, while they shifted their gaze around the display, we displaced select targets. We found that saccade landing position was deviated toward the previous location of the target suggesting that partial parallel programming of target location information was occurring. The saccade landing position was also affected by the new target location, which demonstrates that the saccade landing position was also partially updated following the shift. This pattern was present even for targets that were the subject of the next fixation. Having a greater preview about the sequence path influenced saccade accuracy with saccades being less affected by relocations when there is less preview information. The results demonstrate that landing positions from a saccade sequence are programmed in parallel and combined with more immediate visual signals.

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“…Directing gaze toward a crowded object reduces or completely eliminates crowding. Crowding affects saccade-landing errors [8]. …”

Section: Introductionmentioning

confidence: 99%

Interaction between stimulus contrast and pre-saccadic crowding

Aga-Oglu

Chung

2017

R. Soc. open sci.

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Objects that are briefly flashed around the time of saccades are mislocalized. Previously, robust interactions between saccadic perceptual distortions and stimulus contrast have been reported. It is also known that crowding depends on the contrast of the target and flankers. Here, we investigated how stimulus contrast and crowding interact with pre-saccadic perception. We asked observers to report the orientation of a tilted Gabor presented in the periphery, with or without four flanking vertically oriented Gabors. Observers performed the task either following a saccade or while maintaining fixation. Contrasts of the target and flankers were independently set to either high or low, with equal probability. In both the fixation and saccade conditions, the flanked conditions resulted in worse discrimination performance—the crowding effect. In the unflanked saccade trials, performance significantly decreased with target-to-saccade onset for low-contrast targets but not for high-contrast targets. In the presence of flankers, impending saccades reduced performance only for low-contrast, but not for high-contrast flankers. Interestingly, average performance in the fixation and saccade conditions was mostly similar in all contrast conditions. Moreover, the magnitude of crowding was influenced by saccades only when the target had high contrast and the flankers had low contrasts. Overall, our results are consistent with modulation of perisaccadic spatial localization by contrast and saccadic suppression, but at odds with a recent report of pre-saccadic release of crowding.

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Eyes on crowding: Crowding is preserved when responding by eye and similarly affects identity and position accuracy

Cited by 12 publications

References 48 publications

Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision

Variations in crowding, saccadic precision, and spatial localization reveal the shared topology of spatial vision

The parallel programming of landing position in saccadic eye movement sequences

Interaction between stimulus contrast and pre-saccadic crowding

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