Arithmetic error and neuropsychological test profiles among arithmetic disabled groups : external validation of academic subtypes

Neuropsychological deficits and arithmetic error types among learning disabled (Lp) children have been related to academic achievement patterns and attributed to a common underlying disability. A disability-based explanation predicts that groups of children showing similar (different) subtype patterns will exhibit similar (different) neuropsychological and arithmetic error patterns. Fifty-seven children, aged 8-16 years, with a history of a LD or cranial radiation therapy (CRT) were classified into four groups; A LD (arithmetic impaired), RA LD (reading and arithmetic impaired), A CRT, and N CRT (not subtype A). Neuropsychological composites representing ability areas were computed from intellectual, memory, and psychomotor test scores. Arithmetic errors were scored on the WRAT Arithmetic test using procedures adapted from Strang and Rourke (1985) and converted to composite scores. Profile analyses on composite scores compared groups showing similar (A LD vs A CRT) and different (A LD vs RA LD, A CRT vs N CRT) subtype patterns. Results indicated no significant group profile differences and did not support study predictions. The failure to replicate previous findings is discussed.