ATTENTIONAL CONTROL OVER LANGUAGE LATERALIZATION IN DYSLEXIC-CHILDREN- DEFICIT OR DELAY

Two previous verbal dichotic studies by Kershner and Morton (Neuropsyc hologia 28, 181-198, 1990) using the forced-attention methodology (Bry den, Strategies of Information Processing, Academic Press, London, 197 8) demonstrated that the order in which the ears were monitored (LE fi rst or RE first) determined whether learning disabled children compare d to age-matched nondisabled children were more weakly or strongly lat eralized. The same technique was used with the addition of controls fo r lateral head and eye movements, specific diagnostic criteria to incl ude only phonological dyslexics, IQ and reading level. Dyslexic vs age -matched comparisons replicated the previous studies. The dyslexics pr oduced a weaker REA in the LE first order but a greater number of subj ects with a REA in the RE first order. Reading-matched comparisons sug gested that the order-specific reduced REA in the dyslexics may reflec t a causal deficit of the disorder, whereas the order-specific increas e in the number of dyslexic subjects with a REA was no different than the reading-matched group, implicating a developmental delay. The resu lts suggest that children with dyslexia may suffer from a primary atte ntional impairment in altering the REA. This implicates an underlying difficulty of flexible verbal processing in response to the rapidly ch anging cognitive requirements of reading.