Signs of neurobehavioral dysfunction in a sample of learning disabled children: stability and concurrent validity.

Of 270 learning disabled children with average intelligence and significant delays in reading comprehension a sample of 37 were evaluated for signs of neurobehavioral dysfunction. All such signs--primitive reflexes, equilibrium reactions, and postrotary nystagmus--were reliably assessed. A subsample of 19 children was compared with developmentally normal and mentally retarded samples for the occurrence of tonic neck reflexes and equilibrium reactions. The learning disabled children consistently showed deviancies like those of the retarded children; both of these groups differed from the normal children on most measures. These deviant responses persisted over a 9-mo. period for the learning disabled group. Compared with norms, the total learning disabled sample displayed hyponystagmus, and this depressed nystagmus persisted for 11 mo. Results are discussed in relation to the lack of correlation among the various signs of neurobehavioral dysfunction in the learning disabled children.