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Parent and teacher use of DRO and DRI to reduce aggressive behavior
Analysis and Intervention in Developmental Disabilities Vol. 6, pp. 319-330. 1986 0270-4684/86 $3.00 + .00 Printed in the USA. All rights reserved. Copyright © 1986 Pergamon Journals Ltd.
Parent and Teacher Use of DRO and DRI to Reduce Aggressive Behavior Patrick C. Friman Meyer Children's Rehabilitation Institute University of Nebraska Medical Center
James D. Barnard Private Practice, West Palm Beach,Florida
Karl Altman Montrose M. Wolf University of Kansas
This experiment evaluated parent and teacher use o f reinforcement-based, reductive procedures to treat aggressive pinching in a severely retarded child. A withdrawal and a multiple baseline design were used f o r the analysis. Substantial and lasting treatment effects were obtained at home and school. The benefits and problems associated with parent use o f reinforcement-based, behavioral procedures with severely handicapped children, as well as the comparative effects o f D R O and D R I are discussed.
T h e literature d o c u m e n t i n g that parents can effectively a p p l y b e h a v i o r a l interventions to their children's b e h a v i o r p r o b l e m s is v o l u m i n o u s a n d growing (Dangel & Polster, 1984). A subsection o f t h a t literature shows t h a t p a r e n t a l use o f b e h a v i o r a l techniques can be effective when the children are d e v e l o p m e n t a l l y delayed ( A l t m a n & Mira, 1983). There is little research,
Preparation of this manuscript was partially supported by grants from NICHD (HD 03144, HD 18435, and HD 02528) and from DHHS (MCJ 00944). The authors gratefully acknowledge the assistance of Edward R. Christophersen, Barbara Cochrane, Ginger Garrett, and Laura Charping. Reprint requests to: Patrick C. Friman, MCRI, 444 South 44th Street, Omaha, NE 68131. 319
320 Patrick C. Frimau, James D. Bernard, Kutq Altutatt and Montrose M. Wolf
however, showing that parents can effectively treat their child's behavior problems if the child is severely handicapped. Behavior change programs focused on problem behaviors in handicapped individuals often involve punishment-based, reductive procedures (Wexler, 1978). Recently there has been considerable controversy over the use of punishment procedures with the handicapped (Repp & Dietz, 1978; Wexler, 1978). In response to concerns about punishment procedures, reinforcement-based procedures have been developed and are often used as a successful alternative (Homer & Peterson, 1980; Poling & Ryan, 1982; Repp & Dietz, 1979). The two most commonly used reinforcement-based procedures are differential reinforcement of other behavior (DRO) and the differential reinforcement of incompatible behavior (DRI) (Repp & Dietz, 1979). DRI appears to be the more useful of the two because it is easier to use and because it increases appropriate behavior with a collateral decrease in inappropriate behavior (Dietz, Repp, & Dietz, 1976). DRO can be technically difficult and is designed only to reinforce the absence of a specified response. Yet, in cases where there is not a readily available, incompatible response, DRO may be the treatment of choice. Although schedule-produced side effects can occur in DRO programs, the worst possible side effect appears to be an increase in the undesirable behavior (Homer & Peterson, 1980). When problems occur in programs using DRO, its effects can be enhanced by the inclusion of an adjunctive, punishment-based procedure (Poling & Ryan, 1982; Repp & Dietz, 1974). Choosing treatment strategies based on differential reinforcement schedules represents a dilemma for trainers of the parents of persons with severe handicaps. On the one hand, use of differential reinforcement schedules can be technically difficult, time-consuming, and slower to achieve an effect than punishment programs. On the other hand, differential reinforcement schedules are less likely to result in abusive applications by a frustrated parent, to produce avoidance responses in a child, and to be unacceptable to the community agencies (e.g., schools) that serve the child and are confronted with problem behaviors. Furthermore, in the event that a punishment component is necessary in a reductive program, a rich reinforcement schedule like those used in DRO and DRI could provide the contrast necessary for effective intervention (Solnick, Rincover, & Peterson, 1977). Some published research shows parents can effectively use reinforcementbased, reductive procedures (e.g., Rolider & Van Houten, 1984), but the studies are few in number and do not address problems presented by persons with severe handicaps at home. Additional research on parent use of reinforcement-based, reductive procedures with severely handicapped children is needed. The current study evaluated a mother's use of DRO and DRI to treat her severely retarded daughter's chronic pinching. The study also evalu-
DRO and DRI
321
ated the child's teacher's use of similar procedures to treat pinching at school. METHOD Subjects
Three individuals, a child subject and two adults, the child's mother and the child's teacher, participated in this study. Child. Cindy was a severely retarded, 10-year-old female with a deteriorating, neurological condition, Batten's disease. Cindy could walk only with the aid of a prosthetic walker, could sit erect without support, could not selffeed, had no speech, and was not toilet-trained. Cindy was nonverbal but she was able to use signs for bathroom needs, hunger, and displeasure. She could drink from a cup with minimal gestural and physical assistance. Cindy had severely diminished social skills and resisted all attempts at social interaction by adults and children. Cindy also presented behavior problems, the most extreme of which was aggressive pinching. Cindy was adopted from a state institution at the age of nine. She attended a classroom for the severely, multiply handicapped six hours a day, five days a week. There were six other children in the classroom, all of whom had multiple handicaps accompanied by severe mental retardation. Mother Cindy's adoptive mother was the first adult trained. She was an unmarried, 32-year-old woman, working as a secretary, living alone. The mother found Cindy's pinching extremely frustrating and reported having resorted to corporal punishment, including slapping, to reduce its frequency. None of her attempts to reduce Cindy's pinching were successful and she ultimately contacted an agency specializing in services for parents at risk for child abuse. The agency then contacted the investigators. At the time of the referral, the mother's arms had scratch marks, scabs, and bruises resulting from Cindy's pinching. Teacher Cindy's teacher was the second adult trained. She had a master's degree in special education and was assisted by two full-time aids, both of whom had two years of college. The teacher and the aides had developed their own program to treat Cindy's pinching. The program involved directing hot air from a blow dryer into Cindy's face whenever she pinched. The treatment was highly aversive, perhaps even dangerous, and had little effect on pinching. The teacher and the aides also had scabs and bruises from Cindy's pinches. At the request of the investigators, the blow dryer program was discontinued at the beginning of Cindy's school play baseline.
322 Patrick C. Friman, James D. Barnard, Karl Altman and Montrose M. Wolf Sett&gs H o m e play sessions were conducted on a carpeted, living room floor. During these play sessions, Cindy and her mother sat on the floor facing each other about 12 inches apart. H o m e play sessions were conducted daily and lasted from 10 to 30 minutes. Play time sessions were conducted after dinner at about 6:30 pm. During all play sessions, the mother kept several toys within easy reach. The toys included snap blocks, push-button noisemakers, clear plastic balls with bells inside, musical instruments, busy-boards, and hand puppets. While playing, the mother simply placed toys within Cindy's reach and moved them to attract her interest. She talked as she demonstrated a toy's action. Cindy's interest in particular toys varied and the mother changed toys several times a session. Near the play area was a set of carpeted steps and the bottom step was used as the time-out area. Mealtime sessions were conducted at the dinner table in the kitchen with Cindy at the head of the table and her mother at her immediate right. During the entire experiment, the mother sat with her left arm on the table within 14 inches of Cindy's end of the table (Cindy's extended reach was 181/2 inches). The specific arm placement was used so that variability in pinching would not result from the mother's avoidance. The mother fed Cindy by bringing spoonfuls of food and glasses of juice to her mouth. Meals required an average of 20 minutes to complete. School play sessions were held on a foam recreation mat in Cindy's classroom. School sessions were conducted by the teacher. During the sessions, the teacher and Cindy sat facing each other about 12 inches apart. The teacher used toys such as shape boards, puzzles, and nesting blocks. She interacted with Cindy by giving specific cues and providing verbal consequences for her behavior (e.g., "Put in, Cindy . . . good girl") as well as by conversing with her.
Behavior Definition, Recording, and Reliability The primary observers in the experiment were the investigators, Cindy's mother, and her teacher. A standard definition of pinching was used by all observers in all settings. An occurrence of pinching was recorded whenever Cindy's fingertip(s) (nails) made contact with another person's skin, hair, or garment in a pincer grasp, with the skir~, hair, or garment held within the fingertip(s) with sufficient intensity to produce an observable effect (reddened skin, creased or bunched garment, etc.). Occurrences of the target behavior were recorded using a 10-second, partial interval time sampling method (Powell, Martindale, & Kulp, 1975). Interobserver agreement was assessed by having a second observer make
DRO and DRI
323
periodic, simultaneous observations using the same recording procedure as the primary observer. The percentage of interobserver agreement for occurrence of the behavior was obtained by dividing the two observers' agreements by the sum of their agreements and disagreements, then multiplying by 100°/o.
PROCEDURE
Training
The mother and the teacher were trained to use the procedures by the investigators. The training involved didactic presentations, modeling, written instructions, verbally guided instructions, and feedback. Training time totaled six hours for the mother and three hours for the teacher.
Baseline
During baseline conditions in all settings, the mother and teacher were instructed to respond to pinching in a manner of their own choosing except that the mother was asked not to slap and the teacher was asked not to use the hair dryer to blow hot air contingent on Cindy's pinching. During baseline, the mother ignored all but the most intense pinching, in which cases she would say "No" and extricate herself. The teacher also ignored pinching during baseline except in extreme cases in which she would slap Cindy's hand.
DRO
During DRO, the mother administered positive consequences (e.g., praise, gentle touch) to Cindy when she did not pinch during specified time intervals (DRO) within the play sessions. Initially, DRO intervals were set at 20 seconds (a fixed interval schedule: FI20). During the middle of the first treatment phase (treatment session #6), the intervals were reduced to 10 (FI10) seconds because of the continued high rate of the behavior. The mother used a digital stop watch with a reset button to determine when an interval elapsed. She was instructed to extricate herself when pinched and to reset the interval. Each time the mother delivered a reinforcer, she recorded it o n a push-button event counter. Sessions ended when 30 intervals had ended in reinforcement or when 30 minutes had elapsed, whichever came first. When the schedule was changed to FI10, the first criteria was changed to 60 reinforced intervals.
324 Patrick C. Friman, James D. Barnard, Karl Altman and Montrose M. Wolf D R O + Time-out
When Cindy pinched in this condition, her mother immediately initiated a time out procedure which involved placing Cindy on the step behind the play area for five minutes. The DRO interval remained at l0 seconds during this phase. Sessions were ended when 60 intervals ended in reinforcement, when time-out had been used six times, or when 30 minutes had elapsed, whichever came first. D R O + Response Prevention
When Cindy pinched in this condition her mother and, subsequently, her teacher prevented repeated pinching by holding Cindy's hands stationary for two minutes after the pinch. Mother and teacher were instructed in gentle holding techniques which emphasized using the least amount of pressure necessary to keep Cindy's hands stationary. DRO was suspended during response prevention. The DRO interval was set at two (FI2) seconds at home and 15 (FI15) seconds at school. The 15 second interval was used for school sessions because it was the smallest interval the teacher would consent to use. The mother kept track of the FI2 by counting to herself and the teacher kept track of the FII5 with a digital stopwatch. Sessions were ended when 10 consecutive minutes elapsed without a pinch, when response prevention had been used 15 times, or when 30 minutes had elapsed. DRI
DRI was used only at mealtime. DRI was chosen for mealtime instead of DRO because the mother could not manipulate the necessary paraphernalia (stopwatches, etc.) and because Cindy frequently emitted the incompatible behavior (hands-down) during mealtime baseline sessions. During DRI, the mother brought food or drink to Cindy's mouth only when both of Cindy's hands were on or below the table. Whenever Cindy's hands were not on or below the table, the mother was instructed to say "Hands down" and to keep food and drink completely out of her reach until Cindy put her hands down. Experim en tal Design
The effects of treatment were assessed by means of within-subject comparisons (Baer, Wolf, & Risley, 1968). During home play sessions, the effects of various treatments on Cindy's pinching were assessed using an ABCDAD reversal design wherein A = Baseline, B = Differential Reinforcement, C = Differential Reinforcement plus Time-out, and D = Differential Reinforcement plus Response Prevention. Concurrent baselines were conducted
DRO and D R I
325
during home mealtime sessions and school playtime sessions until a clinically significant treatment effect had occurred in the home playtime sessions. The treatment that produced the clinically significant effect (i.e., differential reinforcement plus response prevention) was subsequently introduced into school play sessions. The effects of DRI on pinching during mealtime sessions were assessed using an AB experimental design. RESULTS
Reliability Interobserver agreement data on Cindy's behavior were obtained during 25% of the home sessions and 27°7o of the school sessions. At least one assessment was obtained during each condition of the study. Two checks were conducted during the first home play baseline, one during the second, two during the DRO condition, two during the DRO + Time-out condition, five during the first DRO + Response Prevention condition, two during the second, seven during the mealtime baseline, three during the DRI condition, three during the school playtime baseline, and two during the school treatment session. The average percentage of agreement for any session was at least 89°7o. The data yielded overall means of 95% agreement (range 89O7o-100o7o) for home sessions and 98O7o agreement (range 91°70-100070) for school sessions.
Child Behavior Figure 1 summarizes data collected during home play, mealtime, and school play sessions. The upper portion of the figure shows the effects of three intervention procedures on the occurrence of pinching during home playtime. During baseline conditions, pinching occurred during a mean of 5007o of the intervals. During DRO conditions, pinching initially decreased but was increasing rapidly at the end of the condition. During the time-out condition, pinching also initially decreased but increased dramatically toward the end of the condition. Following the introduction of response prevention, the trend in the behavior reversed, resulting in near-zero levels toward the end of the condition. During a brief return to baseline, the behavior again increased to high rates. The reintroduction of DRO plus Response Prevention resulted in another sharp decrease in trend, yielding near-zero levels of pinching. At three-months and 15-month follow-up, the behavior did not Occur.
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F I G U R E i. The percentage o f intervals with pinching.in home play, school play, and mealtime sessions. A r r o w in top panel indicates the change from FI2O to FII0. Stud}' points are connected by lines ( _ : ) and followup points are not (,,).
326
DRO and D R I
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As shown in the middle and lower portions of the figure, the data revealed that the variability observed in the home play conditions did not appear to impact the baseline rates of pinching during school play or home mealtime sessions. Prior to the introduction of DRO plus Response Prevention, pinching occurred during nearly 100% of observed intervals during mealtime and 40% of observed intervals during school play sessions. The introduction of treatment during mealtime sessions did not alter the occurrence of the behavior during school play sessions. Following the introduction of DRI during mealtime, the occurrence of pinching was reduced to near-zero levels. And, lastly, following the introduction of treatment during school play sessions, the occurrence of pinching was also reduced to nearzero levels. At three- and 15-month follow-ups, pinching at mealtime was still at near-zero rates. Follow-up data were not collected at school. DISCUSSION The results of this study show that a mother's use of primarily reinforcement-based, behavioral procedures decreased her severely retarded daughter's aggressive pinching to near-zero levels. The results were maintained at three- and 15-month follow-up. The intervention was replicated in the classroom by the child's teacher. Although the teacher used a larger DRO interval (FII5 vs. FI2) the results she obtained were almost identical to those obtained by the mother. Followup points were not collected in the school setting because the school year ended during the study and the teacher did not return to her job the following school year. The study extends the behavioral parent training literature by demonstrating that a parent can use differential reinforcement schedules to treat serious behavior problems in a severely handicapped child (Dangel &'Polster, 1984). This kind of evidence is important because there is an increasing mandate for decreasing the level of aversiveness in programming for the handicapped (Repp & Dietz, 1978; Wexler, 1978). This mandate is likely to affect parents as well as professionals because a current agenda for the U.S. Department of Health and Human Services is permanent home placement for severely handicapped children (Hardy, 1984). The increased level of behavior problems presented by severely handicapped children will increase the need for training parents to use behavioral procedures. In this study, parent use of DRO alone may have increased or at least maintained pinching. Cindy frequently did not pinch during the DRO interval but would pinch just as the mother delivered the reinforcer (gentle touch). Cindy clearly enjoyed the touching and would often drop her hands and orient her body toward her mother shortly after contact was made. Making contact without bein~ pinched, however, was difficult. Pinching
328 Patrick C. Frhnan, James D. Barnard, Karl Altman and Montrose M. Wolf
may have continued in strength throughout the DRO treatment phase as a result of adventitious reinforcement from the accidental pairings of pinchings and reinforcer delivery. Reducing the DRO interval from FI20 to FI10 (treatment session #6) appeared to increase rather than decrease pinching, thus further suggesting that reinforcer deliveries were sustaining the pinching. A time-out component was added to the DRO procedure to attenuate the reinforcing relationship between pinching and reinforcer deliveries. Unfortunately, the inclusion of time-out increased the rate of pinching even further. The problem with the time-out could have involved the reduction in opportunities for reinforcement caused by consecutive timeouts. For example, in treatment session #17, Cindy pinched six times and received six timeouts. Each time-out lasted five minutes and at the end of the sixth time-out, the 30-minute limit for sessions had been reached. When a punishment component is used to increase the effectiveness of DRO, the component should increase or at least not decrease the subject's potential for making contact with the programmed reinforcers. The substitution of response prevention for time-out, combined with a reduction in the DRO interval from 10 seconds to two seconds increased the opportunity to contact reinforcement. In part, increased opportunity for reinforcement was a result of Cindy's relatively slow reaction time. When Cindy's hands were down (for example, when they had been held down for two minutes during response prevention), she often took longer than two seconds to raise her hands and pinch. By that time, the mother, following the FI2 schedule, would already be reinforcing the absence of pinching, at which point Cindy would begin to lower her hands and orient herself towards her mother. The increases in reinforcer delivery quickly decreased the need for response prevention. Response prevention was used an average of 11 times a session during the first six response prevention sessions (N = 31 response prevention sessions). During the following 25 sessions, however, it was used an average of only two times a session and during the follow-up sessions it was not used at all. The inclusion of response prevention eliminated the accidental pairings of reinforcer deliveries and pinching and allowed the DRO to exert its reductive influence on pinching. The results of this study suggest that DRI was more effective than DRO. DRI was effective without an additional suppressive procedure and produced an abrupt decrease in pinching responses. During baseline meals, the mother often delivered food as she was being pinched and, thus, adventitious conditioning may have been a factor at mealtime just as it was during playtime. During DRI, the mother delivered bites of food only when Cindy's hands were on or below the table. As indicated above, Cindy did not have a rapid reaction time and the mother was able to reinforce a hands-down response and simultaneously decrease pinching. DRI, like response preven-
D R O and D R I
329
tion, eliminated pairings of pinching and reinforcer deliveries and allowed the schedule to exert its reductive influence on pinching during mealtime. Because the DRI condition and DRO plus response prevention condition functioned similarly in this study, a conclusion about comparative effectiveness of the two procedures cannot be drawn. The DRI treatment was, however, easier to teach and to implement because it did not require the use of stopwatches and counters. A final question not answered by the study is whether the suppressive effects of response prevention or the reinforcing effects of DRO were more responsible for reducing pinching during play sessions. Previous research has shown that increasing the reinforcing aspects of an environment can increase the effectiveness of a punisher (Solnick et al., 1977). In this study, the reverse appeared to occur: use of an effective punisher increased a child's access to reinforcement. Perhaps the combination of response prevention and DRO provided a critical synergism. A future comparative study involving the use of similar procedures with other parents and other severely handicapped children would address this question more fully. A final implication of the study concerns the need for leaning rich DRO schedules. Differential reinforcement schedules work best when the interval is short, but for the intervention to be efficient in longer term applications the interval must ultimately be lengthened (Homer & Peterson, 1980; Poling & Ryan, 1982). The FI2 schedule used in the home response prevention condition was not leaned during the body of the study. The school treatment sessions, however, began near the end of the study with an FIl5 schedule and achieved near-zero rates of pinching. Furthermore, during follow-up sessions, the mother continued to use DRO + Response Prevention and she reported that she gradually altered the FI2 to a 30-second variable interval schedule. Data on the transitions between the FI2 and the VI30 would be useful but are not available. Strategies for teaching parents to effectively lean reinforcement schedules would be an important question for future research. REFERENCES
Altman, K., & Mira, M. (1983). Training parents of developmentallydisabled children. In J. L. Matson & F. Andrasik (Eds.), Treatment issues and innovations in mental retardation (pp. 303-3"/1). New York:Plenum Press. Baer, D. M., Wolf, M. M., & Risley,T. R. (1968). Somecurrent dimensions of applied behavior analysis. Journal o f Applied Behavior Analysis, 1, 91-97. Dangel, R. E, & Polster, R. A. (1984). Parent training: Foundations o f research and practice. New York:Guilford. Dietz, S. M., Repp, A. C., & Dietz, D. E. (19"/6). Reducing inappropriate classroom behavior of retarded students through three procedures of differential reinforcement. Journal o f Mental Deficiency Research, 20, 155-170. Hardy, D. R. (1984). Adoption of children with special needs: A national perspective. Amer#
330 Patrick C. Friman, James D. Barnard, Karl Airman and Montrose M. Wolf can Psychologist, 39, 901-904. Homer, H. L., & Peterson, L. (I 980). Differential reinforcement of other behavior: A preferred response elimination procedure. Behavior Therapy, 11,449-47 I. Powell, J., Martindale, A., & Kulp, S. (1975). An evaluation of time sample measures of behavior. Journal of Applied Behavior Analysis, 8, 463-471. Poling, A., & Ryan, C. (1982). Differential reinforcement of other behavior schedules: Therapeutic applications. Behavior Modification, 6, 3-21. Repp, A. C., & Dietz, D. E. (1974). Reducing aggressive and self-injurious behavior of institutionalized retarded children through reinforcement of other behavior. Journal of Applied Behavior Analysis, 7, 313-325. Repp, A. C., & Dietz, D. E. (1978). Ethical responsibilities in reductive programs for the retarded. In M. S. Berkler, G. H. Bible, S. M. Boles, D. E. Dietz, & A. C. Repp (Eds.), Current trends for the developmentally disabled, (pp. 67-90). Baltimore: University Park Press. Rcpp, A. C., & Dielz, D. E. (1979). Reinlbrcement based reductive procedures: Training and monitoring performance of institutional staff. Menial Retardation, 17, 221-226. Rolider, A., & Van Houten, R. (1984). The effects of DRO alone and DRO plus reprimands on the undesirable behavior of three children in home settings. Education & Treatment of Children, 7, 17-31. Solnick, J. V., Rincover, A., & Peterson, C. R. (1977). Some determinants of the reinforcing and punishing effects of time out. Journal of Applied Behavior Analysis, 10, 415-423. Wexler, D. B. (1978). Behavior modification and other behavior change procedures: The emerging law and the proposed Florida guidelines. In M. S. Berkler, G. H. Bible, S. M. Boles, D. E. Dietz, & A. C. Repp (Eds.), Current trends for the developmentally disabled, (pp. 25-40). Baltimore: University Park Press.
Parent and Teacher Use of DRO and DRI to Reduce Aggressive Behavior Patrick C. Friman Meyer Children's Rehabilitation Institute University of Nebraska Medical Center
James D. Barnard Private Practice, West Palm Beach,Florida
Karl Altman Montrose M. Wolf University of Kansas
This experiment evaluated parent and teacher use o f reinforcement-based, reductive procedures to treat aggressive pinching in a severely retarded child. A withdrawal and a multiple baseline design were used f o r the analysis. Substantial and lasting treatment effects were obtained at home and school. The benefits and problems associated with parent use o f reinforcement-based, behavioral procedures with severely handicapped children, as well as the comparative effects o f D R O and D R I are discussed.
T h e literature d o c u m e n t i n g that parents can effectively a p p l y b e h a v i o r a l interventions to their children's b e h a v i o r p r o b l e m s is v o l u m i n o u s a n d growing (Dangel & Polster, 1984). A subsection o f t h a t literature shows t h a t p a r e n t a l use o f b e h a v i o r a l techniques can be effective when the children are d e v e l o p m e n t a l l y delayed ( A l t m a n & Mira, 1983). There is little research,
Preparation of this manuscript was partially supported by grants from NICHD (HD 03144, HD 18435, and HD 02528) and from DHHS (MCJ 00944). The authors gratefully acknowledge the assistance of Edward R. Christophersen, Barbara Cochrane, Ginger Garrett, and Laura Charping. Reprint requests to: Patrick C. Friman, MCRI, 444 South 44th Street, Omaha, NE 68131. 319
320 Patrick C. Frimau, James D. Bernard, Kutq Altutatt and Montrose M. Wolf
however, showing that parents can effectively treat their child's behavior problems if the child is severely handicapped. Behavior change programs focused on problem behaviors in handicapped individuals often involve punishment-based, reductive procedures (Wexler, 1978). Recently there has been considerable controversy over the use of punishment procedures with the handicapped (Repp & Dietz, 1978; Wexler, 1978). In response to concerns about punishment procedures, reinforcement-based procedures have been developed and are often used as a successful alternative (Homer & Peterson, 1980; Poling & Ryan, 1982; Repp & Dietz, 1979). The two most commonly used reinforcement-based procedures are differential reinforcement of other behavior (DRO) and the differential reinforcement of incompatible behavior (DRI) (Repp & Dietz, 1979). DRI appears to be the more useful of the two because it is easier to use and because it increases appropriate behavior with a collateral decrease in inappropriate behavior (Dietz, Repp, & Dietz, 1976). DRO can be technically difficult and is designed only to reinforce the absence of a specified response. Yet, in cases where there is not a readily available, incompatible response, DRO may be the treatment of choice. Although schedule-produced side effects can occur in DRO programs, the worst possible side effect appears to be an increase in the undesirable behavior (Homer & Peterson, 1980). When problems occur in programs using DRO, its effects can be enhanced by the inclusion of an adjunctive, punishment-based procedure (Poling & Ryan, 1982; Repp & Dietz, 1974). Choosing treatment strategies based on differential reinforcement schedules represents a dilemma for trainers of the parents of persons with severe handicaps. On the one hand, use of differential reinforcement schedules can be technically difficult, time-consuming, and slower to achieve an effect than punishment programs. On the other hand, differential reinforcement schedules are less likely to result in abusive applications by a frustrated parent, to produce avoidance responses in a child, and to be unacceptable to the community agencies (e.g., schools) that serve the child and are confronted with problem behaviors. Furthermore, in the event that a punishment component is necessary in a reductive program, a rich reinforcement schedule like those used in DRO and DRI could provide the contrast necessary for effective intervention (Solnick, Rincover, & Peterson, 1977). Some published research shows parents can effectively use reinforcementbased, reductive procedures (e.g., Rolider & Van Houten, 1984), but the studies are few in number and do not address problems presented by persons with severe handicaps at home. Additional research on parent use of reinforcement-based, reductive procedures with severely handicapped children is needed. The current study evaluated a mother's use of DRO and DRI to treat her severely retarded daughter's chronic pinching. The study also evalu-
DRO and DRI
321
ated the child's teacher's use of similar procedures to treat pinching at school. METHOD Subjects
Three individuals, a child subject and two adults, the child's mother and the child's teacher, participated in this study. Child. Cindy was a severely retarded, 10-year-old female with a deteriorating, neurological condition, Batten's disease. Cindy could walk only with the aid of a prosthetic walker, could sit erect without support, could not selffeed, had no speech, and was not toilet-trained. Cindy was nonverbal but she was able to use signs for bathroom needs, hunger, and displeasure. She could drink from a cup with minimal gestural and physical assistance. Cindy had severely diminished social skills and resisted all attempts at social interaction by adults and children. Cindy also presented behavior problems, the most extreme of which was aggressive pinching. Cindy was adopted from a state institution at the age of nine. She attended a classroom for the severely, multiply handicapped six hours a day, five days a week. There were six other children in the classroom, all of whom had multiple handicaps accompanied by severe mental retardation. Mother Cindy's adoptive mother was the first adult trained. She was an unmarried, 32-year-old woman, working as a secretary, living alone. The mother found Cindy's pinching extremely frustrating and reported having resorted to corporal punishment, including slapping, to reduce its frequency. None of her attempts to reduce Cindy's pinching were successful and she ultimately contacted an agency specializing in services for parents at risk for child abuse. The agency then contacted the investigators. At the time of the referral, the mother's arms had scratch marks, scabs, and bruises resulting from Cindy's pinching. Teacher Cindy's teacher was the second adult trained. She had a master's degree in special education and was assisted by two full-time aids, both of whom had two years of college. The teacher and the aides had developed their own program to treat Cindy's pinching. The program involved directing hot air from a blow dryer into Cindy's face whenever she pinched. The treatment was highly aversive, perhaps even dangerous, and had little effect on pinching. The teacher and the aides also had scabs and bruises from Cindy's pinches. At the request of the investigators, the blow dryer program was discontinued at the beginning of Cindy's school play baseline.
322 Patrick C. Friman, James D. Barnard, Karl Altman and Montrose M. Wolf Sett&gs H o m e play sessions were conducted on a carpeted, living room floor. During these play sessions, Cindy and her mother sat on the floor facing each other about 12 inches apart. H o m e play sessions were conducted daily and lasted from 10 to 30 minutes. Play time sessions were conducted after dinner at about 6:30 pm. During all play sessions, the mother kept several toys within easy reach. The toys included snap blocks, push-button noisemakers, clear plastic balls with bells inside, musical instruments, busy-boards, and hand puppets. While playing, the mother simply placed toys within Cindy's reach and moved them to attract her interest. She talked as she demonstrated a toy's action. Cindy's interest in particular toys varied and the mother changed toys several times a session. Near the play area was a set of carpeted steps and the bottom step was used as the time-out area. Mealtime sessions were conducted at the dinner table in the kitchen with Cindy at the head of the table and her mother at her immediate right. During the entire experiment, the mother sat with her left arm on the table within 14 inches of Cindy's end of the table (Cindy's extended reach was 181/2 inches). The specific arm placement was used so that variability in pinching would not result from the mother's avoidance. The mother fed Cindy by bringing spoonfuls of food and glasses of juice to her mouth. Meals required an average of 20 minutes to complete. School play sessions were held on a foam recreation mat in Cindy's classroom. School sessions were conducted by the teacher. During the sessions, the teacher and Cindy sat facing each other about 12 inches apart. The teacher used toys such as shape boards, puzzles, and nesting blocks. She interacted with Cindy by giving specific cues and providing verbal consequences for her behavior (e.g., "Put in, Cindy . . . good girl") as well as by conversing with her.
Behavior Definition, Recording, and Reliability The primary observers in the experiment were the investigators, Cindy's mother, and her teacher. A standard definition of pinching was used by all observers in all settings. An occurrence of pinching was recorded whenever Cindy's fingertip(s) (nails) made contact with another person's skin, hair, or garment in a pincer grasp, with the skir~, hair, or garment held within the fingertip(s) with sufficient intensity to produce an observable effect (reddened skin, creased or bunched garment, etc.). Occurrences of the target behavior were recorded using a 10-second, partial interval time sampling method (Powell, Martindale, & Kulp, 1975). Interobserver agreement was assessed by having a second observer make
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periodic, simultaneous observations using the same recording procedure as the primary observer. The percentage of interobserver agreement for occurrence of the behavior was obtained by dividing the two observers' agreements by the sum of their agreements and disagreements, then multiplying by 100°/o.
PROCEDURE
Training
The mother and the teacher were trained to use the procedures by the investigators. The training involved didactic presentations, modeling, written instructions, verbally guided instructions, and feedback. Training time totaled six hours for the mother and three hours for the teacher.
Baseline
During baseline conditions in all settings, the mother and teacher were instructed to respond to pinching in a manner of their own choosing except that the mother was asked not to slap and the teacher was asked not to use the hair dryer to blow hot air contingent on Cindy's pinching. During baseline, the mother ignored all but the most intense pinching, in which cases she would say "No" and extricate herself. The teacher also ignored pinching during baseline except in extreme cases in which she would slap Cindy's hand.
DRO
During DRO, the mother administered positive consequences (e.g., praise, gentle touch) to Cindy when she did not pinch during specified time intervals (DRO) within the play sessions. Initially, DRO intervals were set at 20 seconds (a fixed interval schedule: FI20). During the middle of the first treatment phase (treatment session #6), the intervals were reduced to 10 (FI10) seconds because of the continued high rate of the behavior. The mother used a digital stop watch with a reset button to determine when an interval elapsed. She was instructed to extricate herself when pinched and to reset the interval. Each time the mother delivered a reinforcer, she recorded it o n a push-button event counter. Sessions ended when 30 intervals had ended in reinforcement or when 30 minutes had elapsed, whichever came first. When the schedule was changed to FI10, the first criteria was changed to 60 reinforced intervals.
324 Patrick C. Friman, James D. Barnard, Karl Altman and Montrose M. Wolf D R O + Time-out
When Cindy pinched in this condition, her mother immediately initiated a time out procedure which involved placing Cindy on the step behind the play area for five minutes. The DRO interval remained at l0 seconds during this phase. Sessions were ended when 60 intervals ended in reinforcement, when time-out had been used six times, or when 30 minutes had elapsed, whichever came first. D R O + Response Prevention
When Cindy pinched in this condition her mother and, subsequently, her teacher prevented repeated pinching by holding Cindy's hands stationary for two minutes after the pinch. Mother and teacher were instructed in gentle holding techniques which emphasized using the least amount of pressure necessary to keep Cindy's hands stationary. DRO was suspended during response prevention. The DRO interval was set at two (FI2) seconds at home and 15 (FI15) seconds at school. The 15 second interval was used for school sessions because it was the smallest interval the teacher would consent to use. The mother kept track of the FI2 by counting to herself and the teacher kept track of the FII5 with a digital stopwatch. Sessions were ended when 10 consecutive minutes elapsed without a pinch, when response prevention had been used 15 times, or when 30 minutes had elapsed. DRI
DRI was used only at mealtime. DRI was chosen for mealtime instead of DRO because the mother could not manipulate the necessary paraphernalia (stopwatches, etc.) and because Cindy frequently emitted the incompatible behavior (hands-down) during mealtime baseline sessions. During DRI, the mother brought food or drink to Cindy's mouth only when both of Cindy's hands were on or below the table. Whenever Cindy's hands were not on or below the table, the mother was instructed to say "Hands down" and to keep food and drink completely out of her reach until Cindy put her hands down. Experim en tal Design
The effects of treatment were assessed by means of within-subject comparisons (Baer, Wolf, & Risley, 1968). During home play sessions, the effects of various treatments on Cindy's pinching were assessed using an ABCDAD reversal design wherein A = Baseline, B = Differential Reinforcement, C = Differential Reinforcement plus Time-out, and D = Differential Reinforcement plus Response Prevention. Concurrent baselines were conducted
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during home mealtime sessions and school playtime sessions until a clinically significant treatment effect had occurred in the home playtime sessions. The treatment that produced the clinically significant effect (i.e., differential reinforcement plus response prevention) was subsequently introduced into school play sessions. The effects of DRI on pinching during mealtime sessions were assessed using an AB experimental design. RESULTS
Reliability Interobserver agreement data on Cindy's behavior were obtained during 25% of the home sessions and 27°7o of the school sessions. At least one assessment was obtained during each condition of the study. Two checks were conducted during the first home play baseline, one during the second, two during the DRO condition, two during the DRO + Time-out condition, five during the first DRO + Response Prevention condition, two during the second, seven during the mealtime baseline, three during the DRI condition, three during the school playtime baseline, and two during the school treatment session. The average percentage of agreement for any session was at least 89°7o. The data yielded overall means of 95% agreement (range 89O7o-100o7o) for home sessions and 98O7o agreement (range 91°70-100070) for school sessions.
Child Behavior Figure 1 summarizes data collected during home play, mealtime, and school play sessions. The upper portion of the figure shows the effects of three intervention procedures on the occurrence of pinching during home playtime. During baseline conditions, pinching occurred during a mean of 5007o of the intervals. During DRO conditions, pinching initially decreased but was increasing rapidly at the end of the condition. During the time-out condition, pinching also initially decreased but increased dramatically toward the end of the condition. Following the introduction of response prevention, the trend in the behavior reversed, resulting in near-zero levels toward the end of the condition. During a brief return to baseline, the behavior again increased to high rates. The reintroduction of DRO plus Response Prevention resulted in another sharp decrease in trend, yielding near-zero levels of pinching. At three-months and 15-month follow-up, the behavior did not Occur.
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F I G U R E i. The percentage o f intervals with pinching.in home play, school play, and mealtime sessions. A r r o w in top panel indicates the change from FI2O to FII0. Stud}' points are connected by lines ( _ : ) and followup points are not (,,).
326
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As shown in the middle and lower portions of the figure, the data revealed that the variability observed in the home play conditions did not appear to impact the baseline rates of pinching during school play or home mealtime sessions. Prior to the introduction of DRO plus Response Prevention, pinching occurred during nearly 100% of observed intervals during mealtime and 40% of observed intervals during school play sessions. The introduction of treatment during mealtime sessions did not alter the occurrence of the behavior during school play sessions. Following the introduction of DRI during mealtime, the occurrence of pinching was reduced to near-zero levels. And, lastly, following the introduction of treatment during school play sessions, the occurrence of pinching was also reduced to nearzero levels. At three- and 15-month follow-ups, pinching at mealtime was still at near-zero rates. Follow-up data were not collected at school. DISCUSSION The results of this study show that a mother's use of primarily reinforcement-based, behavioral procedures decreased her severely retarded daughter's aggressive pinching to near-zero levels. The results were maintained at three- and 15-month follow-up. The intervention was replicated in the classroom by the child's teacher. Although the teacher used a larger DRO interval (FII5 vs. FI2) the results she obtained were almost identical to those obtained by the mother. Followup points were not collected in the school setting because the school year ended during the study and the teacher did not return to her job the following school year. The study extends the behavioral parent training literature by demonstrating that a parent can use differential reinforcement schedules to treat serious behavior problems in a severely handicapped child (Dangel &'Polster, 1984). This kind of evidence is important because there is an increasing mandate for decreasing the level of aversiveness in programming for the handicapped (Repp & Dietz, 1978; Wexler, 1978). This mandate is likely to affect parents as well as professionals because a current agenda for the U.S. Department of Health and Human Services is permanent home placement for severely handicapped children (Hardy, 1984). The increased level of behavior problems presented by severely handicapped children will increase the need for training parents to use behavioral procedures. In this study, parent use of DRO alone may have increased or at least maintained pinching. Cindy frequently did not pinch during the DRO interval but would pinch just as the mother delivered the reinforcer (gentle touch). Cindy clearly enjoyed the touching and would often drop her hands and orient her body toward her mother shortly after contact was made. Making contact without bein~ pinched, however, was difficult. Pinching
328 Patrick C. Frhnan, James D. Barnard, Karl Altman and Montrose M. Wolf
may have continued in strength throughout the DRO treatment phase as a result of adventitious reinforcement from the accidental pairings of pinchings and reinforcer delivery. Reducing the DRO interval from FI20 to FI10 (treatment session #6) appeared to increase rather than decrease pinching, thus further suggesting that reinforcer deliveries were sustaining the pinching. A time-out component was added to the DRO procedure to attenuate the reinforcing relationship between pinching and reinforcer deliveries. Unfortunately, the inclusion of time-out increased the rate of pinching even further. The problem with the time-out could have involved the reduction in opportunities for reinforcement caused by consecutive timeouts. For example, in treatment session #17, Cindy pinched six times and received six timeouts. Each time-out lasted five minutes and at the end of the sixth time-out, the 30-minute limit for sessions had been reached. When a punishment component is used to increase the effectiveness of DRO, the component should increase or at least not decrease the subject's potential for making contact with the programmed reinforcers. The substitution of response prevention for time-out, combined with a reduction in the DRO interval from 10 seconds to two seconds increased the opportunity to contact reinforcement. In part, increased opportunity for reinforcement was a result of Cindy's relatively slow reaction time. When Cindy's hands were down (for example, when they had been held down for two minutes during response prevention), she often took longer than two seconds to raise her hands and pinch. By that time, the mother, following the FI2 schedule, would already be reinforcing the absence of pinching, at which point Cindy would begin to lower her hands and orient herself towards her mother. The increases in reinforcer delivery quickly decreased the need for response prevention. Response prevention was used an average of 11 times a session during the first six response prevention sessions (N = 31 response prevention sessions). During the following 25 sessions, however, it was used an average of only two times a session and during the follow-up sessions it was not used at all. The inclusion of response prevention eliminated the accidental pairings of reinforcer deliveries and pinching and allowed the DRO to exert its reductive influence on pinching. The results of this study suggest that DRI was more effective than DRO. DRI was effective without an additional suppressive procedure and produced an abrupt decrease in pinching responses. During baseline meals, the mother often delivered food as she was being pinched and, thus, adventitious conditioning may have been a factor at mealtime just as it was during playtime. During DRI, the mother delivered bites of food only when Cindy's hands were on or below the table. As indicated above, Cindy did not have a rapid reaction time and the mother was able to reinforce a hands-down response and simultaneously decrease pinching. DRI, like response preven-
D R O and D R I
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tion, eliminated pairings of pinching and reinforcer deliveries and allowed the schedule to exert its reductive influence on pinching during mealtime. Because the DRI condition and DRO plus response prevention condition functioned similarly in this study, a conclusion about comparative effectiveness of the two procedures cannot be drawn. The DRI treatment was, however, easier to teach and to implement because it did not require the use of stopwatches and counters. A final question not answered by the study is whether the suppressive effects of response prevention or the reinforcing effects of DRO were more responsible for reducing pinching during play sessions. Previous research has shown that increasing the reinforcing aspects of an environment can increase the effectiveness of a punisher (Solnick et al., 1977). In this study, the reverse appeared to occur: use of an effective punisher increased a child's access to reinforcement. Perhaps the combination of response prevention and DRO provided a critical synergism. A future comparative study involving the use of similar procedures with other parents and other severely handicapped children would address this question more fully. A final implication of the study concerns the need for leaning rich DRO schedules. Differential reinforcement schedules work best when the interval is short, but for the intervention to be efficient in longer term applications the interval must ultimately be lengthened (Homer & Peterson, 1980; Poling & Ryan, 1982). The FI2 schedule used in the home response prevention condition was not leaned during the body of the study. The school treatment sessions, however, began near the end of the study with an FIl5 schedule and achieved near-zero rates of pinching. Furthermore, during follow-up sessions, the mother continued to use DRO + Response Prevention and she reported that she gradually altered the FI2 to a 30-second variable interval schedule. Data on the transitions between the FI2 and the VI30 would be useful but are not available. Strategies for teaching parents to effectively lean reinforcement schedules would be an important question for future research. REFERENCES
Altman, K., & Mira, M. (1983). Training parents of developmentallydisabled children. In J. L. Matson & F. Andrasik (Eds.), Treatment issues and innovations in mental retardation (pp. 303-3"/1). New York:Plenum Press. Baer, D. M., Wolf, M. M., & Risley,T. R. (1968). Somecurrent dimensions of applied behavior analysis. Journal o f Applied Behavior Analysis, 1, 91-97. Dangel, R. E, & Polster, R. A. (1984). Parent training: Foundations o f research and practice. New York:Guilford. Dietz, S. M., Repp, A. C., & Dietz, D. E. (19"/6). Reducing inappropriate classroom behavior of retarded students through three procedures of differential reinforcement. Journal o f Mental Deficiency Research, 20, 155-170. Hardy, D. R. (1984). Adoption of children with special needs: A national perspective. Amer#
330 Patrick C. Friman, James D. Barnard, Karl Airman and Montrose M. Wolf can Psychologist, 39, 901-904. Homer, H. L., & Peterson, L. (I 980). Differential reinforcement of other behavior: A preferred response elimination procedure. Behavior Therapy, 11,449-47 I. Powell, J., Martindale, A., & Kulp, S. (1975). An evaluation of time sample measures of behavior. Journal of Applied Behavior Analysis, 8, 463-471. Poling, A., & Ryan, C. (1982). Differential reinforcement of other behavior schedules: Therapeutic applications. Behavior Modification, 6, 3-21. Repp, A. C., & Dietz, D. E. (1974). Reducing aggressive and self-injurious behavior of institutionalized retarded children through reinforcement of other behavior. Journal of Applied Behavior Analysis, 7, 313-325. Repp, A. C., & Dietz, D. E. (1978). Ethical responsibilities in reductive programs for the retarded. In M. S. Berkler, G. H. Bible, S. M. Boles, D. E. Dietz, & A. C. Repp (Eds.), Current trends for the developmentally disabled, (pp. 67-90). Baltimore: University Park Press. Rcpp, A. C., & Dielz, D. E. (1979). Reinlbrcement based reductive procedures: Training and monitoring performance of institutional staff. Menial Retardation, 17, 221-226. Rolider, A., & Van Houten, R. (1984). The effects of DRO alone and DRO plus reprimands on the undesirable behavior of three children in home settings. Education & Treatment of Children, 7, 17-31. Solnick, J. V., Rincover, A., & Peterson, C. R. (1977). Some determinants of the reinforcing and punishing effects of time out. Journal of Applied Behavior Analysis, 10, 415-423. Wexler, D. B. (1978). Behavior modification and other behavior change procedures: The emerging law and the proposed Florida guidelines. In M. S. Berkler, G. H. Bible, S. M. Boles, D. E. Dietz, & A. C. Repp (Eds.), Current trends for the developmentally disabled, (pp. 25-40). Baltimore: University Park Press.