THE ROLE OF VISION IN THE DEVELOPMENT OF ABSTRACTION ABILITY

The study reported here investigated the differences in verbal and non verbal abstraction ability of adults who became blind before age 2 and those who lost their sight after the age of 5, when their expressive language ability would have been more fully developed. No significant differences between the two groups were found in these areas, as measu red by the Cognitive Test for the Blind and the Verbal subscale of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The finding that educational level affects the variability of scores on the WAIS-R sugg ests that differences in educational experiences may significantly inf luence individuals' performance on standardized measures of intelligen ce.