精神遅滞児の認知発達段階と問題行動に関する研究

Abstract

Seventy-one mentally retarded childen (19 autistic, 52 non-autistic ; age 7-19 years) from a school for handicapped childen were studied as to cognitive development, using Ohta's scale for evaluating cognitive development level based on language comprehension (Ohta's stage) and other developmental scales. Behavior problems were also examined. Ohta et al. have reported that Ohta's scale is valid and useful in evaluating cognitive development in autistic children. The present paper reports on the utility of Ohta's stage in non-autistic children, and the relationship between cognitive development level and behavior problems in mentally retarded children. Findings are summarized as follows : 1) In non-autistic children, there was a temporal correlation between Ohta's stage and other developmental scales (standard developmental tests, speech development, symbolic play development), suggesting that in non-autistic children as well, Ohta's stage may serve well as a scale for cognitive development, and reflect symbolic representational functioning. 2) Development of symbolic play and imitation lagged behind development of language in some autistic children. On the other hand, there was concordance between development of symbolic play and imitation, and development of language, in all non-autistic children. 3) Non-autistic children of lower cognitive development level more often exhibited stereotypic behaviors and hyperkinesis. On the other hand, ritualistic and compulsive behaviots were noted in non-autistic children, irrespective of cognitive development level. The relation between these behavior problem and the cognitive development level found in non-autistic children was similar to the relation that has been reported in autistic children. 4) With regard to the entire study population, most behavior problems in feeding, elimination and sleeping were closely associated with cognitive development level, and were more often noted in children of lower cognitive development level. Some behavior problems may often occur in the sensorimotor period and hardly occur in the symbolic representational period.