Reading Disability, Perceptual Continuity, and Phi Thresholds

Abstract

Birch and Kephart hold contradictory views regarding the intactness of visual form perception in disabled readers. Although Birch's techniques demonstrate form discrimination, they do not necessarily measure discrimination by means of form. To provide a critical test of Kephart's assumption regarding a qualitatively inferior perceptual process in disabled readers, a test based upon the phi phenomenon was employed. One study involved 20 disabled readers and 20 normal achievers, a second, 12 disabled readers and 12 normal achievers. The results support Birch's claim regarding the intactness of visual form discrimination in disabled readers.