A STUDY OF COGNITIVE-DEVELOPMENT AND BEHAVIOR PROBLEMS IN MENTALLY-RETARDED CHILDREN

Cognitive development in seventy-one mentally retarded children (19 au tistic, 52 non-autistic; aged 7-19 years) from a school for handicappe d children was studied, using Ohta's scale for evaluating cognitive de velopment level based on language comprehension (Ohta's stage), and ot her developmental scales. Behavior problems were also examined. The pr esent study reports on the utility of Ohta's stage in non-autistic chi ldren, and the relationship between cognitive development level and be havior problems in mentally retarded children. In non-autistic childre n, there were temporal correlations between Ohta's stage and other dev elopment scales (a standard developmental test, speech development, sy mbolic play development, imitation development), suggesting that in no n-autistic children as well, Ohta's stage may serve well as a scale fo r cognitive development, and reflect symbolic representational functio ning. In non-autistic children, most behavior problems in feeding, eli mination and sleeping, hyperkinesis, hypokinesis, stereotyped behavior s, self-injurious behavior and licking were closely associated with co gnitive development level, and were more often noted in children of lo wer cognitive development level rather than only in the severely menta lly retarded children. Some behavior problems may often occur in the s ensorimotor period and hardly occur in the symbolic representational p eriod.