Numerical and arithmetical cognition: A longitudinal study of process and concept deficits in children with learning disability

Based on the stability and level of performance on standard achievement res ts in first and second grade (mean age in first grade = 82 months), childre n with IQ scores in the low-average to high-average range were classified a s learning disabled (LD) in mathematics (MD), reading (RD), or both (MD/RD) . These children (n = 42), a group of children who showed variable achievem ent test performance across grades (n = 16), and a control group of academi cally normal peers (n = 35) were administered a series of experimental and psychometric tasks. The tasks assessed number comprehension and production skills, counting knowledge, arithmetic skills, working memory, the ease of activation of phonetic representations of words and numbers, and spatial ab ilities. The children with variable achievement test performance did not di ffer from the academically normal children in any cognitive domain, whereas the children in the LD groups showed specific patterns of cognitive defici t, above and beyond the influence of IQ. Discussion focuses on the similari ties and differences across the groups of LD children. (C) 2000 Academic Pr ess.