Chronobiological aspects of stereotyped motor behaviour in mentally retarded children.

摘要: Normally developed children show many diverse patterns of behaviour. By contrast, the behaviour severely mentally retarded is restricted mainly to primitive motor acts called stereotypes. Due severity mental retardation, these are also markedly reduced in their susceptibility environmental influences. Systematic observations pathological make it feasible investigate possible endogenous mechanisms related activities. The stereotyped behaviours six handicapped were observed continuously for several days. Each child performed at least two forms Using spectra variance and cross-correlation analysis, data investigated with respect underlying periodicities. A 2.5-hour cycle was consistently found every activity observed. Furthermore, stable phase relationships revealed between periodic variations different movements one same child. Thus temporal courses hand oral stereotypes synchronous, whereas head whole-body delayed by half a waving. relationship discussed periodicity Kleitman's "Basic Rest Activity Cycle".