Learning disability in adults: a comparison of two indices of differential cognitive impairment derived from the Wechsler scales.

Two indices descriptive of patterns of differential cognitive impairment have been derived from principal component analyses of the normative data of the Wechsler scales for adults (WAIS-R) and children (WISC-R), respectively. The former index is sensitive to the test-specific cognitive effects of unilateral cerebral damage in adults. The latter accurately describes the pattern of subtest scores produced by learning-disabled children. The present study reviews the available WAIS and WAIS-R data from adults with learning disability in order to determine which of these two indices more precisely delineates their pattern of test performance; the index derived from the children's test appears to be the one best able to do so.