Lindberg, J.S., Iwata, B.A. & Kahng, S. (1999).
On the relation between object manipulation and stereotypic self-injurious behavior.
Journal of Applied Behavior Analysis,
32, 51-62.
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 SIB 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 SIB stayed within baseline levels.
We then attempted to increase object manipulation further by (a) reinforcing object manipulation, (b)
blocking SIB while reinforcing manipulation, and (c) preventing SIB 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 SIB for 1
participant but produced no increase in object manipulation. When the 2nd participant was
prevented from engaging in SIB 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 SIB;
therefore, direct interventions to reduce SIB are required.
DESCRIPTORS: self-injurious behavior, stereotypy, object manipulation, functional analysis,
differential reinforcement, response blocking, protective equipment