On the relation between object manipulation and stereotypic self-injurious behavior

Results from a number of studies have shown an inverse relationship between stereotypic behavior and object manipulation. The purposes of this study were to determine whether techniques similar to those used previously (prompting and reinforcement) would be effective in increasing object manipulation under both prompted and unprompted conditions, and to ascertain whether increases in object manipulation would result in decreases in stereotypic self-injurious behavior (SIB). Two individuals with developmental disabilities who engaged in SIE maintained by automatic reinforcement participated. Results showed that object manipulation increased From baseline levels when experimenters prompted participants to manipulate leisure items, but that object manipulation was not maintained under unprompted conditions, and rates of SIE stayed within baseline level. We then attempted to increase object manipulation Further by (a) reinforcing object manipulation, (b) blocking SIE while reinforcing manipulation, and (c) preventing SIE by applying protective equipment while reinforcing object manipulation. Reinforcing object manipulation alone did not affect levels of object manipulation. Blocking effectively reduced attempts to engage in SIE for 1 participant but produced no increase in object manipulation. When the 2nd participant was prevented from engaging in SIE through the use of protective equipment, rates of object manipulation increased dramatically but were not maintained when the equipment was removed. These results suggest that stimulation derived from object manipulation, even when supplemented with arbitrary reinforcement, may not compete with stimulation produced by stereotypic SIE; therefore, direct interventions to reduce SIE are required.