An analogue assessment of hand stereotypies in two cases of Rett syndrome.

Stereotype hand movements are one behavioural manifestation of Rett syndrome, a neurodegenerative disorder resulting in severe mental retardation. They are neuropathological in origin, and constitute a barrier to the acquisition and exhibition of more developmentally appropriate behaviours, as well as posing a health risk for some individuals. The present study used an analogue assessment procedure, in which experimental conditions were constructed varying in the consequences delivered contingent upon the exhibition behaviour, to examine environmental correlates to the moment-to-moment expression of these behaviours. Results are discussed regarding their implications for intervention and research into the aetiology of stereotypic behaviours.