Vibratory or Visual Stimulation Reduces Self-Injury

Although self-injurious behaviour (SIB) may be maintained by its sensory consequences independently of any social reinforcement, there have been no studies carried out which have compared the effects of alternate sources of sensory stimulation on SIB. Vibratory stimulation (a massager) and visual stimulation (flashing red light) were presented separately to a female with profound mental retardation by means of a combined reversal and alternating-treatments design. Both vibratory and visual stimulation equally and significantly decreased the subject's SIB from approximately 35% to 8% and 2% respectively of the time observed in both the treatment room and later, in the subject's typical environment.