Specific learning disabilities: a neuropsychological perspective.

A dispersion in cognitive abilities is expected in normal populations. Specific learning disabilities would represent an extreme polarity in a continuum of normal cognitive dispersion. Three propositions relative to learning disabilities are advanced in the present paper. First, specific learning disabilities are expected to be found for diverse cognitive functions, even though some of these specific learning disorders have yet to be described in scientific literature. Second, it is noted that specific "factors" can be affected in cases of learning disabilities. Lastly, a parallel between focal neuropsychological syndromes and specific learning disabilities is proposed. Developmental learning difficulties would represent dysfunctional or dysmaturational defects; whereas neuropsychological syndromes represent a consequence of acquired structural brain pathology.