The perception of static subjective contours in infancy.

Only a few empirical investigations have focused on infants' ability to perceive static subjective contours. Furthermore, these experiments have provided contradictory findings regarding the age at which this capability emerges. The present study examined the development of infants' sensitivity to an elliptical version of the subjective circle described by Ehrenstein. A habituation-dishabituation procedure was used to test the ability of 4-, 5-, and 7-month-old infants (N = 128) to differentiate between a subjective ellipse and a nonsubjective pattern that was constructed by displacing the inducing elements of the illusory figure. Results indicated that even the 4-month-olds were capable of discriminating between the subjective ellipse and the nonillusory display. A control experiment secured that this behavior was not generated by certain local differences between the test patterns. Furthermore, the results suggest that the perceived strength of the subjective contour was size dependent. This observation is discussed within the context of more recent neurophysiological models.