The predominant models on the emergence and maintenance of stereotypy in individuals with developmental disabilities are based on operant and neurobiological interpretations of the behavior. Although the proponents of the two models maintain largely independent lines of research, operant and neurobiological interpretations of stereotypy are not…

The relation between the movement dynamic properties of sitting still and of seated body-rocking in adults with stereotyped movement disorder and mental retardation and a contrast group of typically developing age-matched adults was examined. Continuous measurement of sequential displacements in center-of-pressure was made using a force platform…

A concurrent-operants design was used to analyze the repetitive behavior of observing reflective surfaces while simultaneously engaging in erratic gross-motor body movements (EBMs) exhibited by a young boy diagnosed with autism. The assessment involved an evaluation of preference for controlled (i. e., the participant controlled the visual…

Objective: The purpose of this study was to assess heritability of activity, attention, and impulsivity by comparing young monozygotic (MZ) twins with dizygotic (DZ) twins using objective measures. Method: The OPTAx test is an infrared motion analysis to record the movement pattern during a continuous performance test. Seventeen MZ and 12 same…