ANALYSIS OF THE REINFORCEMENT AND EXTINCTION COMPONENTS IN DRO CONTINGENCIES WITH SELF-INJURY

Previous research has shown that self-injurious behavior (SIB) maintained by positive reinforcement may be reduced under differential-reinforcement-of-other-behavior (DRO) contingencies. In this study, we conducted an analysis of the reinforcement and extinction components of DRO while treating the self-injury of 3 women with developmental disabilities. A functional analysis revealed that each subject's SIB was maintained by positive reinforcement in the form of attention. Subsequent reinforcer assessments identified preferred and nonpreferred stimuli for later use in conjunction with DRO. Results showed high rates of SIB for all 3 subjects during baseline, which persisted when DRO was implemented without the relevant extinction component (withholding of attention for SIB) for 2 of the subjects. Low rates of SIB were observed for all subjects when DRO plus extinction was implemented or when extinction was implemented alone, suggesting that extinction may be a critical component of DRO schedules.     

EFFECTS AND SIDE EFFECTS OF DRO AS TREATMENT FOR SELF-INJURIOUS BEHAVIOR

A three-part controlled case study is presented in which severe and longstanding self-injurious behavior exhibited by a 9-year-old-boy was treated successfully with differential reinforcement of other behavior. In Phase 1, an experimental analysis demonstrated that the boy's scratching was not maintained by environmental contingencies; instead, it appeared that the self-injurious behavior was a stereotypic (automatically reinforced) response. In Phase 2, the effects of an escalating differential-reinforcement-of-other-behavior schedule mediated through token reinforcement (pennies) were evaluated in a reversal design. Results showed that differential-reinforcement-of-other-behavior eliminated self-injurious behavior very quickly and for periods of time as long as 30 min. A noteworthy side effect observed during Phase 2 was the occurrence of crying behavior following the nondelivery of reinforcement. In Phase 3, the token program was gradually extended in 30-min increments throughout the day. Additionally, results of a brief multielement manipulation showed that the effects of token reinforcement were superior to those of a more easily administered differential reinforcement of other behavior based on social reinforcement, which differed little from baseline.     

THE ROLE OF ATTENTION IN THE TREATMENT OF ATTENTION-MAINTAINED SELF-INJURIOUS BEHAVIOR: NONCONTINGENT REINFORCEMENT AND DIFFERENTIAL REINFORCEMENT OF OTHER BEHAVIOR

Because there are potentially serious limitations to differential reinforcement of other behavior (DRO) (which is probably the most widely used treatment procedure for behavior problems), we examined an alternative procedure—noncontingent reinforcement (NCR). Three females with developmental disabilities, all of whom engaged in severe self-injurious behavior, participated. During a pretreatment functional analysis, each subject's self-injury was shown to be differentially sensitive to social attention as a maintaining consequence. Next, each subject was exposed to a DRO treatment and an NCR treatment. During DRO, attention was delivered contingent on the absence of self-injury for prespecified intervals. During NCR, attention was delivered on a fixed-time schedule that was not influenced by the subject's behavior. Results showed that both procedures were highly effective in reducing self-injury, probably because the functional reinforcer for self-injury was used during treatment. Furthermore, there was evidence that NCR attenuated several of the limitations of DRO. These results are particularly interesting in light of the long experimental history of NCR as a control rather than as a therapeutic procedure.     

COMPARISON OF EXTINCTION,DRO 0-SEC,AND DRO 6-SEC IN THE ELIMINATION OF IMITATIVE RESPONDING UNDER DISCRETE-TRIAL PARADIGMS1

Imitative response levels were observed for normal 5-yr-old children within a discrete-trial imitation paradigm. Following imitation training sessions, children were observed under conditions of contingent reinforcement for three experimental sessions. Following the contingent reinforcement phase, children were then observed under reversal conditions for four sessions. A 3 × 4 repeated measures design was employed for observing response decrements under conditions of extinction, DRO 6-sec, and DRO 0-sec. The DRO 0-sec group demonstrated a significantly greater decrement in imitative responding than did the DRO 6-sec and extinction group. The differences in effects between the two DRO conditions and results from previous studies in which DRO procedures have had little effect in reducing imitative responding, suggest an incomplete understanding of the ways in which DRO procedures may operate.     

AN ANALYSIS OF REINFORCER SUBSTITUTABILITY USING OBJECT MANIPULATION AND SELF-INJURY AS COMPETING RESPONSES

The concept of reinforcer substitutability proposes a continuum of interactions among reinforcers in a given situation. At one end of this continuum, reinforcers are substitutable, with one reinforcer being readily traded for another. We conducted an analysis of reinforcers that were substitutable with those produced by self-injurious behavior (SIB). Three individuals with profound developmental disabilities, whose SIB appeared to be maintained by automatic reinforcement, participated. Results of three experiments showed that (a) object manipulation and SIB were inversely related when leisure materials and SIB were concurrently available, with participants showing almost complete preference for object manipulation; (b) attempts to reduce SIB using the preferred objects as reinforcers in differential reinforcement contingencies were unsuccessful for all 3 participants; and (c) participants' preferences for SIB or object manipulation systematically changed when reinforcer cost (the amount of effort required to obtain the object) was varied. Results of the three experiments illustrate the importance of examining interactions among concurrently available reinforcers when conducting reinforcer assessments.     

False-positive maintenance of self-injurious behavior by access to tangible reinforcers.

Results of a functional analysis indicated that the hand mouthing of a woman with developmental disabilities was maintained by multiple sources of control (sensory stimulation and access to a leisure item). Further assessment revealed that access to several other items also produced high rates of hand mouthing. However, direct observation conducted in the woman's home indicated that none of these items was delivered contingent upon hand mouthing. When the consequence observed most frequently in the home was incorporated into the functional analysis, rates of hand mouthing were no higher than they were during an alone condition. We concluded that hand mouthing, although maintained by automatic reinforcement, was also susceptible to social contingencies when exposed to them during assessment, thereby producing a partially false-positive outcome.     

NONCONTINGENT ESCAPE AS TREATMENT FOR SELF-INJURIOUS BEHAVIOR MAINTAINED BY NEGATIVE REINFORCEMENT

We extended research on the role of noncontingent positive reinforcement following a functional analysis of attention-maintained self-injurious behavior to self-injury maintained by negative reinforcement in 2 young males with developmental disabilities. During a pretreatment functional analysis, each participant's self-injury was shown to be differentially sensitive to escape from instructional activities as negative reinforcement. During noncontingent escape, escape from learning activities was provided on a fixed-time schedule that was not influenced by the participant's behavior. One participant was also exposed to differential negative reinforcement of other behavior. During this condition, escape from instructional activities was provided contingent on the omission of self-injury for prespecified intervals. Results showed that the provision of escape, even when noncontingent, resulted in significant reductions in self-injury. These results are particularly interesting in light of the experimental history of noncontingent reinforcement as a control rather than as a therapeutic procedure. Noncontingent escape is discussed as a form of extinction that may be less likely than other forms of extinction to produce severe side effects.     

Additional-delay schedules: A continuum of temporal contingencies by varying food delay

Pigeons performed on discrete-trial, temporally defined schedules in which the food delay (D) was adjusted according to the latency of the key peck (X) and two schedule parameters (t and A). The schedule function was D = A(t − X), where D is the experienced delay between a response and a reinforcer. The schedule parameter t is the maximum value below which the present contingencies occur. A is the additional delay to reinforcement for each second the response latency is shorter than the t value. When A = 0 s, the schedule is a continuous reinforcement schedule with immediate reinforcement. When A = 1 s, the schedule is a conjunctive fixed-ratio 1 fixed-time t-s schedule. When A approaches infinity, the schedule becomes a differential reinforcement of long latency schedule. The latencies for subjects with t = 10 s and t = 30 s were observed with the present schedules having seven values for A between 0 s and 11 s. In addition, the latencies for subjects for which t = 30 s were observed at an A value of 31 s to 41 s. As the A value increased, the latencies approached the t value for subjects for which t = 10 s. The latencies for 30-s-t subjects did not approach t, even when the A value was 41 s. The latencies for 10-s-t subjects at 11-s A value were longer than those under yoked conditions having exactly the same delays/interreinforcement intervals. These results demonstrated a continuum of latency related to the schedule continuum (value of A) at a small t value.     

Competition between noncontingent and contingent reinforcement schedules during response acquisition

We examined the extent to which noncontingent reinforcement (NCR), when used as treatment to reduce problem behavior, might interfere with differential reinforcement contingencies designed to strengthen alternative behavior. After conducting a functional analysis to identify the reinforcers maintaining 2 participants' self-injurious behavior (SIB), we delivered those reinforcers under dense NCR schedules. We delivered the same reinforcers concurrently under differential-reinforcement-of-alternative-behavior (DRA) contingencies in an attempt to strengthen replacement behaviors (mands). Results showed that the NCR plus DRA intervention was associated with a decrease in SIB but little or no increase in appropriate mands. In a subsequent phase, when the NCR schedule was thinned while the DRA schedule remained unchanged, SIB remained low and mands increased. These results suggest that dense NCR schedules may alter establishing operations that result in not only suppression of problem behavior but also interference with the acquisition of appropriate behavior. Thus, the strengthening of socially appropriate behaviors as replacements for problem behavior during NCR interventions might best be achieved if the NCR schedule is first thinned.     

Clarifying an ambiguous functional analysis with matched and mismatched extinction procedures

Results of functional analysis were ambiguous in suggesting that self-injurious behavior (SIB) was maintained by escape, sensory reinforcement, or both. To help clarify these results, we compared escape extinction, sensory extinction, and the combined treatments. Sensory extinction proved to be a necessary and sufficient treatment, whereas escape extinction failed to decrease SIB. These analyses helped to clarify the function of SIB and to identify an effective and efficient treatment.     

Using pretreatment and posttreatment assessments to enhance and evaluate existing treatment packages.

Pretreatment assessment data were used to enhance an existing treatment package to reduce aggression and to increase positive social interactions between a young boy and his peers. Based on the results of pretreatment assessments, additional reinforcement (differential reinforcement of alternative behavior with adult attention) and punishment (performing a nonpreferred task during time-out) components were added to an existing nonresetting differential reinforcement of other behavior (access to peers unless aggression occurred) plus time-out procedure. A posttreatment component analysis of the additional treatment components indicated that the reinforcement component facilitated positive social interactions and the punishment component suppressed aggression towards peers.     

A PRELIMINARY PROCEDURE FOR PREDICTING THE POSITIVE AND NEGATIVE EFFECTS OF REINFORCEMENT-BASED PROCEDURES

In the current investigation, a modification was made to the preference assessment described by Pace, Ivancic, Edwards, Iwata, and Page (1985) to predict the effects of stimuli when used in a differential-reinforcement-of-other-behavior (DRO) schedule for 2 clients with severe self-injurious behavior (SIB) and profound mental retardation. Based on the results of the preference assessment, three types of stimuli were identified: (a) high-preference stimuli associated with high rates of SIB (HP/HS), (b) high-preference stimuli associated with relatively lower rates of SIB (HP/LS), and (c) low-preference stimuli associated with low rates of SIB (LP/LS). Consistent with the results of the preference assessment, the DRO schedule with HP/HS stimuli resulted in increased SIB, and the DRO schedule with LP/LS stimuli resulted in no changes in SIB. HP/LS stimuli were demonstrated reinforcers but did not result in a change in SIB when used in a DRO schedule. Thus, the stimulus preference assessment may be useful clinically in some situations for predicting both the beneficial and the negative side effects of stimuli in DRO procedures.     

PLAY VERSUS ALONE CONDITIONS AS CONTROLS DURING FUNCTIONAL ANALYSES OF SELF-INJURIOUS ESCAPE BEHAVIOR

We compared the effects of continuous reinforcement (play) and alone conditions as controls during functional analyses for 66 individuals whose self-injurious behavior (SIB) was maintained by escape. In every case, SIB was lower during both control conditions than it was during the test (demand) condition. However, SIB was lowest during the alone condition more often than it was during the play condition. Circumstances under which the alone condition might serve as an alternative or more suitable control for escape-maintained problem behaviors are discussed.     

A COMPARISON OF TWO PROCEDURES FOR PROGRAMMING THE DIFFERENTIAL REINFORCEMENT OF OTHER BEHAVIORS

The relative effectiveness of two methods of programming DRO schedules of reinforcement was examined in two experiments. In these two methods, reinforcement is delivered if inappropriate responding is not occurring (a) at the end of an interval (momentary DRO), or (b) throughout the entire interval (whole-interval DRO). In Experiment 1, the effects of these schedules on disruptive responding of three retarded students were assessed in a multiple-baseline design. For two students, the momentary schedule occurred first and was ineffective, whereas the whole interval that followed was effective; for the third student, the whole-interval schedule occurred first and was effective, and reduced responding was maintained under the momentary schedule. In Experiment 2, baseline and the two DRO schedules were each presented in random order each day to one student in an alternating treatments design. The momentary DRO schedule reduced responding, but the whole-interval schedule was more effective.     

COMBINING NONCONTINGENT REINFORCEMENT AND DIFFERENTIAL REINFORCEMENT SCHEDULES AS TREATMENT FOR ABERRANT BEHAVIOR

Research has shown that noncontingent reinforcement (NCR) can be an effective behavior-reduction procedure when based on a functional analysis. The effects of NCR may be a result of elimination of the contingency between aberrant behavior and reinforcing consequences (extinction) or frequent and free access to reinforcers that may reduce the participant's motivation to engage in aberrant behaviors or mands. If motivation is momentarily reduced, behavior such as mands may not be sensitive to positive reinforcement. In this study, for 3 children with aberrant behavior maintained by tangible positive reinforcement, differential-reinforcement-of-alternative-behavior schedules were superimposed on NCR schedules to determine if mands could be strengthened. Results for the participants indicated that NCR did not preclude reinforcement of mands.     

The impact of functional analysis methodology on treatment choice for self-injurious and aggressive behavior.

Self-injurious behavior (SIB) and aggression have been the concern of researchers because of the serious impact these behaviors have on individuals' lives. Despite the plethora of research on the treatment of SIB and aggressive behavior, the reported findings have been inconsistent regarding the effectiveness of reinforcement-based versus punishment-based procedures. We conducted a literature review to determine whether a trend could be detected in researchers' selection of reinforcement-based procedures versus punishment-based procedures, particularly since the introduction of functional analysis to behavioral assessment. The data are consistent with predictions made in the past regarding the potential impact of functional analysis methodology. Specifically, the findings indicate that, once maintaining variables for problem behavior are identified, experimenters tend to choose reinforcement-based procedures rather than punishment-based procedures as treatment for both SIB and aggressive behavior. Results indicated an increased interest in studies on the treatment of SIB and aggressive behavior, particularly since 1988.     

USE OF NEGATIVE REINFORCEMENT IN THE TREATMENT OF SELF-INJURIOUS BEHAVIOR

Behavioral assessment procedures were used to determine the maintaining conditions of self-injury exhibited by 2 children with severe multiple handicaps. For both children, negative reinforcement (escape from grooming activities) was determined to be the maintaining reinforcer for self-injury (hand/arm biting) within an alternating treatments design. The treatment packages involved the use of negative reinforcement (brief escape from grooming activities) contingent upon a behavior that was incompatible with self-injury (reaching and pressing a microswitch that activated a prerecorded message of “stop”). Treatment was evaluated with a reversal design for 1 child and with a multiple baseline across grooming activities for the 2nd child. The treatment led to a marked decrease in self-injury for both children. At follow-up, high rates of self-injury were reported for the 1st child, but low rates of self-injury and an increase in task-related appropriate behavior were observed for the 2nd child.