What crowding can tell us about object representations

Abstract

In crowding, perception of a target usually deteriorates when flanking elements are presented next to the target. Surprisingly, adding further flankers can lead to a release from crowding. In previous work we showed that, for example, vernier offset discrimination at 9° of eccentricity deteriorated when a vernier was embedded in a square. Adding further squares improved performance. The more squares presented, the better the performance, extending across 20° of the visual field. Here, we show that very similar results hold true for shapes other than squares, including unfamiliar, irregular shapes. Hence, uncrowding is not restricted to simple and familiar shapes. Our results provoke the question of whether any type of shape is represented at any location in the visual field. Moreover, small changes in the orientation of the flanking shapes led to strong increases in crowding strength. Hence, highly specific shape-specific interactions across large parts of the visual field determine vernier acuity.

Capsule networks as recurrent models of grouping and segmentation

“…Critically, the uncrowding effect depends on the global stimulus configuration. For example, if some squares are replaced by stars, performance deteriorates again (3 rd bar; [28]).…”

“…When a flanking square surrounds the target, performance drops, i.e., there is strong crowding [29,30]. Surprisingly, adding more flankers can reduce crowding strongly, depending on the spatial configuration of the flankers (Fig 1B; [28]). Hence, the global configuration of visual elements across large regions of the visual field influences perception of the small vernier target.…”

“…In crowding, objects that are easy to identify in isolation appear as jumbled and indistinct when clutter is added [9,[23][24][25][26][27][28]. Consider the following example: Fig 1A shows a vernier target, i.e., two vertical lines separated by a horizontal offset.…”

A few remarks on spatial interference in visual stimuli

“…b The two signals are out of phase, causing them to cancel. Since the two signals have equal amplitudes, their sum becomes zero in this case visual system (e.g., Clarke, Herzog, & Francis, 2014;Hermens, Luksys, Gerstner, Herzog, & Ernst, 2008;Manassi, Lonchampt, Clarke, & Herzog, 2016;Shin, Chung, & Tjan, 2017). 2 The present investigation examines this assumption.…”

A few remarks on stimulus power and interference in visual stimuli

“…A number of authors (Breitmeyer & Ogmen, 2000;Hermens et al, 2008;Manassi et al, 2016;Shin et al, 2017) Interference has here been discussed in terms of how it may reduce the stimulus power of stimulus elements. There is evidence to indicate that interference, by selectively reducing stimulus power, may also have the effect of shifting the distribution of stimulus power along some stimulus dimension (e.g., orientation).…”