VISUAL-PERCEPTUAL FUNCTIONING IN EDUCABLE MENTALLY RETARDED CHILDREN

Abstract

The purpose of this study was to explore the role of visual perception in children's performance on a commonly-used measure of visual motor functioning and to ascertain the degree to which early reading achievement could be predicted from knowledge of children's visual discrimination ability and visual-motor integration.;The theoretical rationale of the study was based on work done by Bortner and Birch (1960; 1962), who found in brain-damaged populations that subjects were often able to discriminate geometric designs accurately although they could not reproduce them motorically. Bortner and Birch termed this phenomenon "perceptual and perceptual-motor dissociation" and argued that it was not always valid to infer perceptual adequacy or inadequacy from results obtained on visual-motor reproductive tasks. The present study tested these workers' hypotheses with educable mentally retarded children, with the additional step taken of measuring the children's reading achievement and correlating it with their visual and visual-motor functioning.;To meet the objectives of the study, 46 special education pupils classified as educable mentally retarded, ranging in age from 7 to 12 years, were given the block design subtest of the WISC-R with an extended time limit and a lowered criterion for discontinuance. Next, the children were presented with a series of author-developed multiple-choice cards each containing a picture of a correct design and two experimental alterations of the design, and were asked to point to the one matching the WISC-R stimulus design. Additionally, each child was administered the WRAT reading section and the three word-matching subtests of the Slingerland Test.;The findings showed that instances of good discrimination in the face of design reproduction failure were common. Both block design and the discrimination task correlated moderately with reading achievement but neither was a particularly useful predictor of early reading. Results were discussed in terms of a discontinuous and hierarchical development of the child's visual and visual-motor abilities. Clinicians assessing children's perceptual-motor abilities were advised to exercise caution in diagnosing "perceptual deficits" from tests such as block design, in which such variables as motor ability and higher integrative skills may operate to cloud the true picture of the child's visual discrimination.