Perceptual retardation in reading disability cases

The non-verbal part of the Alpha Test of the Otis Quick-Scoring Tests was selected as an instrument for the measurement of perceptual development, and a perceptual-intellective lag index was obtained by subtracting the MA obtained on this test from the MA obtained from Stanford, Wechsler-Bellevue, or WISC. Of 33 children with reading disability, 27 were perceptually retarded, and the average perceptual lag for the entire group was 2.24 years. Of 7 adults so tested, 4 were perceptually retarded. For a large majority of the cases studied, perceptual retardation was a significant factor in reading disability.