| This study involved a systematic evaluation of the differential effectiveness of vibration presented contingently in a DRO schedule and vibration presented noncontingently as compared to no treatment in the reduction of self-injurious stereotypy in ten retarded individuals. Through the use of a yoked-subjects design, amount of vibration was equated for both subjects of a pair, and a no-treatment probe, used periodically throughout the study, provided evidence of functional control. Overall, vibration was moderately effective in reducing self-injurious behavior and had the beneficial side effect of increasing the sociability of the subjects. However, for most subjects, the effectiveness of vibration was transient, losing strength either within the daily observation periods or over days of the experiment. Noncontingent vibration was slightly more effective overall and would be much easier and more cost effective to administer. Subject variability of response to vibration in general, and to the two types of vibration in particular, warrants further investigation of this cost effective, nonaversive procedure. |
