An evaluation of the impact of matched and unmatched stimulation on visual stereotypy maintained by automatic reinforcement

A combination of a reversal and multi-element design was used to examine the impact of stimuli that produces sensory consequences that are similar (matched) and dissimilar (unmatched) to those produced by visual stereotypy in three children with autism. A functional analysis was conducted with all three participants to determine if their stereotypy was maintained by automatic reinforcement and not social consequences. Preference assessments were performed at the beginning of each session in order to discover toys that the participants favored in two categories: those that produce visual stimulation and those that are not meant to do so. Baseline was followed by an alternation of noncontingent access to matched and unmatched stimuli. Environmental enrichment did decrease the participants' stereotypic behavior. However, results from the matched and unmatched conditions varied across participants.