How crowding, masking, and contour interactions are related: A developmental approach

Abstract

Young children are characterized by poor visual performances. Visual crowding, lateral interactions, and contour detection are critical functions for visual perception, context effect, and recognition that develop over the years up to maturity. The age at which the maturation's onset of the functions can be observed and the functions' underlying neural basis remain unclear. Here we used a development approach to investigate the onset of the foveal visual functions in order to learn about their neuronal basis and their relationships. We measured lateral interactions, crowding, and contour integration in participants aged 3-15 years. The results show that very young children do not exhibit collinear facilitation; rather, their vision is dominated by suppression and a high degree of crowding. Our results show sequential changes in the visual functions in parallel with the development of facilitation-that is, a significant reduction in crowding and an improved contour detection threshold. Our data suggest that the correlation between the onset age of maturation of collinear facilitation with crowding reduction and improvement of contour integration has underlying mutual neuronal mechanisms.

Perceptual Learning in Children With Infantile Nystagmus: Effects on Visual Performance

“…26,27 A recent study on crowding in 3-to 15-year-old children with normal vision demonstrated that vision in children younger than 7 years is dominated by suppressive interactions between contours. 28 Crowding can be iovs.arvojournals.org j ISSN: 1552-5783 measured in two different ways: one is the maximum distance at which a distractor causes degraded perception of the target (the extent), and the second is the amount of loss in visual acuity when the interaction is at its maximum (the intensity). 4 The crowding extent is the minimum distance needed between a threshold-size target and flankers to allow target recognition.…”

Effect of stimulus configuration on crowding in strabismic amblyopia

“…Thus the timeframe in which strabismus exerts its influence on the developing visual system can be inferred. The findings of our study suggest that in strabismic amblyopia, the visual system is affected before the maturation of crowding is complete, at around 6-12 years, depending on the study design (Bondarko & Semenov, 2005;Doron et al, 2015;Jeon, Hamid, Maurer, & Lewis, 2010).…”

“…A further explanation for the increased crowding in the amblyopic eyes could stem from the findings of Lev et al (2014), where crowding was shown to be greater where larger perceptive fields are used. In foveal viewing in amblyopic eyes, similar to with young children, larger processing units may be used (Doron et al, 2015).…”

“…Crowded acuity has a longer timescale of maturation in children than uncrowded acuity (Doron, Spierer, & Polat, 2015;Drover et al, 2008;Langaas, 2011;Morad, Werker, & Nemet, 1999;Norgett & Siderov, 2014;Pan et al, 2009). During typical maturation of the visual system, a decrease in crowding is accompanied by an improvement in higher level functions such as contour integration and lateral interactions (Doron et al, 2015;Kovács, Kozma, Fehér, & Benedek, 1999). It follows that visual acuity measured using more complex targets-such as full letter charts, which require higher level processingmay not be expected to show maturity until later than is the case for simple targets and may therefore be more affected in amblyopia.…”

Developmental visual perception deficits with no indications of prosopagnosia in a child with abnormal eye movements

“…We assessed BN's contour integration ability using the contour integration card set (Kovacs et al 1999, Doron et al 2015) and compared it to previously published age-typical performance as well as to the group of age-matched controls participating in our study. Each card in the set consists of a round contour made of collinear Gabor patches ("signal") that is embedded in randomly oriented Gabor patches ("noise").…”