Development of Illusory-Contour Perception in Infants

Abstract

We investigated whether infants from 8-22 weeks of age were sensitive to the illusory contour created by aligned line terminators. Previous reports of illusory-contour detection in infants under 4 months old could be due to infants' preference for the presence of terminators rather than their configuration. We generated preferential-looking stimuli containing sinusoidal lines whose oscillating, abutting terminators give a strong illusory contour in adult perception. Our experiments demonstrated a preference in infants 8 weeks old and above for an oscillating illusory contour compared with a stimulus containing equal terminator density and movement. Control experiments excluded local line density, or attention to alignment in general, as the basis for this result. In the youngest age group (8-10 weeks) stimulus velocity appears to be critical in determining the visibility of illusory contours, which is consistent with other data on motion processing at this age. We conclude that, by 2 months of age, the infant's visual system contains the nonlinear mechanisms necessary to extract an illusory contour from aligned terminators.

The development of contour interpolation: Evidence from subjective contours

“…For infants, the likelihood of responding to subjective contours depends on the support ratio (Otsuka, Kanazawa, & Yamaguchi, 2004), overall size (Kavsek, 2002), and presence of motion cues (e.g., Curran, Braddick, Atkinson, Wattam-Bell, & Andrew, 1999). Young infants (3-and 4-month-olds) respond to subjective contours when the support ratio is high (66%) (Otsuka et al, 2004) or when motion is available (Curran et al, 1999;Johnson & Aslin, 1998). In addition, 4-month-olds respond to subjective contours in relatively small figures, whereas even 7-month-olds fail to do so in a large figure, suggesting a critical influence of the spatial separation between the inducers in infants' perception of subjective contours (Kavsek, 2002).…”

Infants' perception of directional alignment of texture elements on a spherical surface

“…because motion attracts the infants' attention, and apparently exerts a facilitating effect on the infants' performance in visual habituationdishabituation tasks (e.g. Curran et al, 1999).…”

Sound enhances detection of visual target during infancy: A study using illusory contours

“…We used illusory contours (Kanizsa, 1979) as visual targets because previous studies have consistently shown that infants prefer looking at stimulus arrays that induce illusory contours to looking at those that do not (Curran, Braddick, Atkinson, Wattam-Bell, & Andrew, 1999;Kavšek, 2002;Otsuka, Kanazawa, & Yamaguchi, 2004;Otsuka & Yamaguchi, 2003). In addition, Otsuka and colleagues reported that even 3-and 4-month-olds showed a preference for illusory contours when the support ratio was relatively high.…”