is reinforcing a behavior that is incompatible with the behavior targeted for reduction. When an individual is exhibiting a behavior such as head slapping, a DRI could be giving the individual a tennis ball to roll back and forth between his or her hands. This behavior is incompatible because a person cannot roll a ball between their hands and slap their head simultaneously. Positive reinforcement such as "good playing" could be given along with the DRI. The advantage to using DRI is that it allows the appropriate behavior to occur and also decreases the probability of the undesirable behavior. DRO, sometimes referred to as differential reinforcement of zero rates of behavior, involves the presentation of a reinforcing stimulus contingent on the nonoccurrence of the behavior. Some individuals exhibiting SIB may pick at their skin or bite themselves. This behavior can leave the person with mild abrasions, scabs, or scars on his or her skin. Using the DRO technique, reinforcement should be given for every behavior except the target behavior. This means that the individual can be exhibiting many other undesirable behaviors, but they will only be reinforced if they do not exhibit the target behavior. The observer could make a statement such as, "If you can go 30 minutes without skin picking or biting, you may have a candy bar at the end of the 30 minute session." If the subject picks or bites him or herself at any time during the 30 minute session, they will receive no reward. The effectiveness of this procedure depends on the reinforcer selected. The reinforcer must be equal to or exceeding the reinforcer that is currently maintaining the undesirable behavior. DRL is the reinforcement of lower rates of behavior. This technique can be used to decrease a behavior to a more tolerable level. An individual exhibiting self-stimulatory behavior such as hand mouthing (inserting fingers or hand into the mouth) may be causing damage to him or herse...
