Stimulus overselectivity is widely accepted as a stimulus control abnormality in autism spectrum disorders and subsets of other populations. Previous research has demonstrated a link between both chronological and mental age and overselectivity in typical development. However, the age at which children are developmentally ready to respond to…

Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…

Purpose: This research examined how the color distribution of symbols within a visual aided augmentative and alternative communication array influenced the speed and accuracy with which participants with and without Down syndrome located a target picture symbol. Method: Eight typically developing children below the age of 4 years, 8 typically…

Visual perception may be a developmental prerequisite to some types of social understanding. The ability to perceive social information given visual motion appears to develop early. However, children with autism have profound deficits in social cognitive function and may fail to see social motion in the same way that typically developing children…

Background: Williams syndrome (WS) and Down syndrome (DS) are two neurodevelopmental genetically based disorders which exhibit mental retardation with a unique cognitive profile. Naming in individuals with WS and DS has been investigated in several studies, with results indicating that the performance of children with WS and DS is at a similar…

Infants in four age groups--three, six, nine and twelve months--were exposed to an experimental procedure designed to assess the extent to which such subjects were capable of discriminating between different orientations of the same form, and the extent to which they were capable of recognizing the identity between different orientations of the…