Hemispheric specialization for speech in retarded children.

Hemispheric asymmetries in retarded and normal children were examined in dichotic tests which followed extensive auditory-discrimination training and which required non-verbal responses to digits or words. Mean right-ear advantages were smaller for the retarded group than for the normal group. However, most retarded children individually showed clear right- or left-ear advantages and absolute ear advantages were similar for the two groups. These data suggest atypical, but not reduced, functional asymmetries for retarded children.