| Abstract: | Age and sex differences in left- and right-hemisphere processing were assessed with 2 dichotic listening tasks in a sample of 48 control and 48 learning-disabled (LD) children ranging in age from 6 yrs 9 mo to 12 yrs 4 mo. Children were presented with consonant–vowel syllables (CVs) and simple square-wave and complex square-wave tones. Neither age nor sex differences in response accuracy or lateralized processing of CV stimuli were evident for control children. Borderline significance was obtained for tonal stimuli. In contrast, CV stimuli elicited a bilateral response in younger LD children, and tonal stimuli elicited a bilateral response in all LD children. Furthermore, control children were oppositely lateralized for verbal and nonverbal stimuli, whereas LD Ss exhibited a general processing bias to the same hemisphere. These data support the theory that LD children may lack the necessary functional specialization required for lateralized processing of such stimuli. In addition, these data do not fully support the developmental invariance hypothesis and may even suggest a putative right-hemisphere or bilateral processing deficiency in LD children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
