A comparison of procedures for programming noncontingent reinforcement schedules

We compared two methods for programming and thinning noncontingent reinforc ement (NCR) schedules during the treatment of self-injurious behavior (SIB) . The participants were 3 individuals who had been diagnosed with mental re tardation. Results of functional analyses indicated that all participants' SIE was maintained by positive reinforcement (i.e., access to attention or food). Following baseline, the effects of two NCR schedule-thinning procedu res were compared in multielement designs. One schedule (fixed increment) w as initially set at fixed-time 10-s reinforcer deliveries and was also thin ned according to fixed-time intervals. The other schedule (adjusting IRT) w as initially determined by participants' baseline interresponse times (IRTs ) for SIE and was thinned based on IRTs observed during subsequent treatmen t sessions. Results indicated that both schedules were effective in initial ly reducing SIE and in maintaining response suppression as the schedules we re thinned.