Conditioning histories and setting stimuli controlling engagement in stereotypy or toy play

Two experiments were performed with five developmentally disabled individuals to test the relationship between toys as conditioned reinforces and stereotypy. Data consisted of the number of 5 second intervals containing toy play and stereotypy in 10 minute sessions. Experiment 1 was done with two students who were selected because they had a history of playing with preferred toys and were not noted for stereotypy. They were observed under phases with and without toys to determine whether the removal of the toy would occasion increases in stereotypy. Probes were done 5 and 6 months after the third phase. Results showed that removal of the toys occasioned stereotypy and reinstatement of the toys eliminated stereotypy. Experiment 2 was done with three young adults who were selected because they had low or nonexistent toy play and high rates of stereotypy. After the baseline, they were conditioned to play with toys during training sessions and observed in separate free operant sessions (baseline conditions). A multiple baseline across subjects was used. Five probe sessions with the toys were conducted with each participant after 6 months without access to the toys. Results showed that the training sessions affected the free operant behavior of each subject in variable degrees. The participants engaged in substantially less stereotypy and substantially more toy play. Six months later when the toys were reinstated without additional training, stereotypy was low and toy play high. Conditioning reinforcers for play, such as toys, may result in a durable and possibly more cost effective procedure for dealing with stereotypy.