Developmental trends in interpolation and its spatial constraints: A comparison of subjective and occluded contours

Abstract

We examined interpolation in 6-and 9-year-old children and in adults, in the two most common forms of fragmentation: subjective and partially occluded contours. Experiment 1 examined the effects on adults' interpolation of contour geometry, specifically, the effect of a scale-dependent factor (i.e., retinal size) and a scale-independent factor (i.e., support ratio). For both subjective and partially occluded contours, interpolation was affected more by support ratio than absolute size. However, subjective contours were less precisely interpolated and their interpolation was affected more by support ratio than was the case for partial occlusion. Experiment 2 used a subset of retinal size and support ratio levels in children and adults. Interpolation of both subjective and occluded contours improved significantly with age, with the two types of contours equally affected by spatial constraints during early childhood. However, while interpolation of occluded contours became more precise with age and less dependent on support ratio by adulthood, interpolation of subjective contours was less improved and became even more tied to support ratio in adulthood. The implications of these differential age-related changes in the spatial constraints on interpolation of the two types of contours for the mechanisms of perceptual completion are discussed.

The role of early visual input in the development of contour interpolation: the case of subjective contours

“…The deficit in interpolation after monocular deprivation is an example of a sleeper effect (Maurer et al, 2007): visual deprivation in the first few months of life prevents the development of the ability to interpolate fragmented contours into a shape, a perceptual skill that normally is not adult-like until after 9 years of age (Hadad et al, 2010;Hadad, Maurer & Lewis, 2015). This sleeper effect indicates that, immediately after birth, coordinated binocular input plays a critical role in the construction and/or preservation of the neural architecture that will later mediate the mechanism of interpolation.…”