Further Evaluation of Presentation Format of Competing Stimuli for Treatment of Automatically Maintained Challenging Behavior

Abstract

Behavioral interventions have been effective in reducing automatically maintained skin picking for individuals with disabilities including autism spectrum disorder (ASD). A competing stimulus assessment (CSA) is typically utilized in behavioral intervention and assessment to identify potential stimuli which compete with the reinforcer for various forms of challenging behavior (CB). Treatment evaluations have validated the results of these assessments by demonstrating competing stimuli may reduce levels of CB. In Phase 1 of this study, we conducted a functional analysis (FA) to determine what variables were maintaining skin picking of an 11-year-old girl diagnosed with ASD. In Phase 2, we conducted a CSA to determine which stimulus competed the most with skin picking. In Phase 3, we utilized a multielement with reversal design to compare the effectiveness of three presentation formats: (a) single stimulus (single), (b) multiple stimuli (multiple), and (c) alternating stimuli (alternating) in reducing levels of automatically maintained CB. We found noncontingent access to a single item was the most effective intervention to decrease skin picking. This study adds to the literature on reducing CB in children with ASD by incorporating a CSA before the evaluation of different formats of delivering competing stimuli, across extended duration session times.

Keywords

autism spectrum disorder competing stimulus noncontingent reinforcement self-injurious behavior skin picking

Skin picking is a type of self-injurious behavior (SIB) that includes picking, scratching, rubbing, gouging, and squeezing one’s own skin in a repetitive manner (Deckersbach, Wilhelm, Keuthen, Baer, & Jenike, 2002; Lang et al., 2010). Chronic and untreated skin picking poses a serious threat to the individual’s physical health. Specifically, skin picking may lead to tissue damage, scarring, infection, lesions, and deep gouging that can result in visible disfigurement and hinder overall daily functioning (O’Sullivan, Phillips, Keuthen, & Wilhelm, 1999). Researchers conducted a survey of self-injurious skin pickers and reported that 90% of such individuals experienced tissue damage (i.e., minor sores), 61% reported infections due to skin picking, and in 45% skin picking left “deep craters” in the skin (Wilhelm et al., 1999). Surveys among dermatologic populations have yielded lifetime prevalence rates between 2% and 4%, suggesting that self-injurious skin picking is not a rare condition (Griesemer, 1978; Gupta, Gupta, & Haberman, 1987). The prevalence rate ranges from 1.4% to 5.4% in typically developing individuals (Hayes, Storch, & Berlanga, 2009; Keuthen, Koran, Aboujaoude, Large, & Serpe, 2010); however, the rate for individuals diagnosed with specific developmental disabilities such as Prader–Willi syndrome, is as high as 86% (Didden, Korzilius, & Curfs, 2007).

While there are several reports showing that skin picking is common among individuals with developmental disabilities, knowledge about effective treatment approaches is sparse. Treatment approaches have included combinations of differential reinforcement, providing preferred items and activities stimuli (e.g., toys), wearing protective clothing (e.g., helmets or gloves), response interruption and redirection, punishment, and extinction. In the majority of reviewed studies that included some form of functional behavior assessment, skin picking was identified to be maintained by automatic reinforcement, or in part maintained by automatic reinforcement (Lang et al., 2010). Effective behavioral treatments for automatically maintained skin picking typically include some form of differential reinforcement (Lang et al., 2010). However, differential reinforcement usually requires the continuous observation of another individual, or therapist, with few exceptions (cf. Toussaint & Tiger, 2012). Continuous observation can pose a problem for clinicians working with individuals who engage in covert skin picking as it requires increased time and resources. An effective intervention for automatically maintained challenging behavior that does not require continuous observation by another person is noncontingent access to competing items or activities (e.g., DeLeon, Anders, Rodriguez-Catter, & Neidert, 2000; Piazza, Adelinis, Hanley, Goh, & Delia, 2000).

Piazza et al. (2000) looked to extend the literature on competing items involving matched stimuli to three dissimilar forms of aberrant behavior (i.e., dangerous climbing and jumping, saliva manipulation, and hand mouthing). The results of functional analyses suggested that each behavior was automatically reinforced. Preference assessments were used to identify two classes of stimuli: items that matched the hypothesized sensory consequences of aberrant behavior (matched stimuli) and items that produced sensory consequences that were not similar to those produced by the aberrant behavior (unmatched stimuli). The effects of providing continuous and noncontingent access to either the most highly preferred matched or the most highly preferred unmatched stimuli were assessed relative to a condition in which no stimuli were available. Overall, results suggested that providing access to items that matched the hypothesized sensory consequences of aberrant behavior may be more effective than simply selecting stimuli either arbitrarily or based on the results of preference assessments alone.

Multiple studies have demonstrated a reduction in skin picking when using noncontingent access to preferred stimuli (DeLeon et al., 2000; Ladd, Luiselli, & Baker, 2009; Lane, Thompson, Reske, Gable, & Barton-Arwood, 2006; Mulick, Hoyt, Rojahn, & Schroeder, 1978); however, effects of habituation and changing preferences pose limitations to this treatment.

To address limitations, variations in the presentation format of competing items have been examined. For example, DeLeon et al. (2000) evaluated noncontingent access to competing items for an 11-year-old individual diagnosed with ASD who engaged in SIB in the form of skin picking. The researchers identified preferred stimuli via a parent interview to be included in a preference assessment to determine a hierarchy of preferred stimuli. The two most highly preferred items were identified. The researchers then conducted a functional analysis (FA). Their results suggested that SIB was maintained by automatic reinforcement and that access to toys could effectively reduce the behavior. They then evaluated noncontingent access to competing items across different conditions: a single set of items, rotating items, and multiple items formats. In the single-set condition, only one set of toys (crayons and coloring book) was continuously available to the participant. In the rotating-set condition, one of two sets of toys was available and the therapist would switch one set of toys out for another every 10 min. During the multiple-set conditions, all sets of toys were available to the participant. All conditions were effective at reducing the rate of SIB; however, the presentation of a single set of highly preferred items ceased to compete with SIB over the course of 30-min sessions, possibly due to habituation of these items. This possibility was strengthened by the observation that the participant rarely returned to the items once she ceased playing with them during the single-set condition. By contrast, results suggested that either rotating toy sets or providing multiple toy sets extended the reductive effects of treatment based on stable low rates of SIB.

Identifying the most effective items for use in interventions using noncontingent delivery of stimuli has been done using competing stimuli assessments (CSA). The purpose of a CSA is to systematically identify stimuli that will displace automatically maintained challenging behavior by presenting them one at a time, and measure engagement relative to challenging behavior. Piazza et al. (2000) did this by extending the literature on matched stimuli to three dissimilar forms of aberrant behavior (e.g., dangerous climbing and jumping, saliva manipulation, and hand mouthing). The results of functional analyses suggested that each behavior was automatically reinforced. Preference assessments were used to identify two classes of stimuli: items that matched the hypothesized sensory consequences of aberrant behavior (matched stimuli) and items that produced sensory consequences that were not similar to those produced by the aberrant behavior (unmatched stimuli). The effects of providing continuous and noncontingent access to either the most highly preferred matched or the most highly preferred unmatched stimuli were assessed relative to a condition in which no stimuli were available. Overall results suggested that providing access to items that matched the hypothesized sensory consequences of aberrant behavior identified by the CSA may be more effective than simply selecting stimuli either arbitrarily or based on the results of preference assessments alone.

The purpose of this study was to replicate DeLeon et al. (2000), and to extend research on this topic by conducting a CSA to identify items that compete with challenging behavior prior to determining the effect of the treatment delivered in different formats. Additionally we examined which format of item delivery is most effective in reducing skin picking using noncontingent access to items identified by the CSA for longer session durations.

Method

Participant and Setting

Molly was a 12-year-old female diagnosed with autism spectrum disorder (ASD) and vision impairment. Her vision impairment was severe and she required the use of a white cane for walking, and she could not grasp items placed directly in front of her without locating by touch. Molly was high functioning and could communicate in full sentences. She was referred for the treatment of SIB in the form of skin picking. Her parents reported SIB occurred on a daily basis, frequently occurred covertly, and resulted in scars and open wounds on her legs, arms, and back. At the time of the study, Molly wore arm sleeves during all waking hours to prevent the SIB, but the SIB still occurred.

The study took place at a University’s outpatient behavior clinic. All sessions occurred in a therapy room (3 m × 3.5 m) equipped with a video camera to record and observe the sessions. A table and two chairs were present in the room during all sessions.

Data Collection and Interobserver Agreement

Graduate students were trained using the video training described by Dempsey, Iwata, Fritz, and Rolider (2012) and used laptop computers to collect data using BDataPro software (Bullock, Fisher, & Hagopian, 2017). Duration data were collected for SIB, item engagement, and occupied hands. These data were converted to a percentage of intervals by dividing the number of 10-s intervals in which target behaviors occurred by the total number of 10-s intervals. SIB (i.e., skin picking) was defined as Molly moving her fingernails with pressure on her skin. The onset of skin picking occurred when Molly placed her hand on her skin and scratched or picked. The offset occurred when she removed her hand from specific locations. The duration of Molly’s SIB was recorded during the study due to the behavior not being a discrete event. Engagement with each item was defined as manual manipulation of the item with one or two hands. For some items, Molly could engage in SIB and engagement simultaneously. Occupied hands was defined as Molly folding her hands together with fingers interlocking. The mean percentage of total time of duration of skin picking, engagement with item, and duration of occupied hands was calculated.

A second observer collected data during 33% of FA sessions, 33% of CSA sessions, and 33% of treatment evaluation sessions. A data collection system was used to calculate partial interval agreement; and graduate students collected exact agreement procedural fidelity. Interobserver agreement of target behavior was calculated by dividing the lower number of responses by the higher number for all 10-s intervals and multiplying by 100. Procedural fidelity was calculated by dividing the number of correct responses by the number of correct responses plus errors and multiplying by 100. For the FA, average interobserver agreement was 91.8% with a range of 88.2% to 97.1 % and average procedural fidelity was 100%. For CSA, average interobserver agreement was 89.9% with a range of 74% to 98.8% and average procedural fidelity was 96.4% with a range of 75% to 100%. For the treatment evaluation, interobserver agreement was 95% with a range of 76.8% to 100% and average procedural fidelity was 99.3% with a range of 92% to 100%.

Procedure

Phase 1: FA

An FA of SIB in the form of skin picking was conducted with Molly. The FA was based on the procedures described by Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994). All sessions were 5 min and conducted in a multielement design. Conditions used for the FA were ignore, attention, play, escape, and play with no items. Because Molly had a vision impairment, an ignore condition had to be conducted instead of an alone condition to maintain her safety. This was due to mobility issues that could arise because of the unfamiliar environment of the clinic room. In the ignore condition, the therapist was in the room with Molly, but ignored all behavior and all instances of SIB. An extended ignore condition was conducted to screen for an automatic function (Querim et al., 2013). In the attention condition, the therapist pretended to engage in a work-related activity. Contingent upon SIB, the therapist provided a pat on the back with a statement of concern to Molly. During the play condition, which was used as a control condition, Molly had noncontingent access to her preferred items. The therapist provided attention every 30 s, or when Molly bid for attention, and placed no demands. The play with no items condition was identical to the play condition, except the client did not have access to any items. The therapist provided attention every 30 s, or when Molly bid for attention, and placed no demands. This condition was used to identify whether or not the items in the play condition competed with SIB. In the escape condition, the session therapist continuously delivered gross motor demands using a three-step prompting procedure. Contingent upon SIB, the therapist gave Molly a 30 s break from demands.

Phase 2: Competing stimulus assessment

The purpose of the CSA was to identify items that Molly could engage with to reduce her levels of skin picking. Procedures were similar to those described by Fisher, DeLeon, Rodriguez-Catter, and Keeney (2004). Eight stimuli were selected for the assessment based on parent report of items that Molly enjoyed and items that she could easily manipulate. A list of eight items plus a control condition in which no items were present was created and randomized. These items were a BopIt, baby doll, squeeze ball, sticky ball, horse, beaded necklace, fidget bracelet, and stuffed animals. A therapist was in the room with Molly, but provided no interaction and ignored all behaviors. Before each session with items began, the therapist presented an item to Molly and said, “You can play with this item or you don’t have to. You can place it on the table if you don’t want to play with it.” The therapist used hand-over-hand guidance to show Molly where the table was located. Molly had access to the item for 5 min. During control sessions, no items were present, so the therapist simply said, “I have some work to do,” and turned away from Molly. Molly’s engagement with the item, her duration of skin picking, and her duration of occupied hands was recorded. Three trials, 5 min each, were conducted with each item.

Phase 3: Treatment evaluation

We used the three items from the CSA that had the highest engagement associated with the lowest percentage of time engaged in skin picking (BopIt, stuffed animals, and squeeze ball) in the treatment evaluation. The purpose of the treatment was to identify the most effective way to present items to compete with skin picking. Three conditions were used: single item, multiple items, and alternating items. The purpose of the multiple items and alternating items conditions was to prevent habituation from occurring (DeLeon et al., 2000). Sessions were 20 min based on caregiver input that this would be useful for their needs because this would be the maximum amount of time Molly might be unsupervised at home. Molly was able to be unsupervised at home because she was familiar with rooms and locations of objects in her environment. We used an ABAB reversal design with an embedded multielement design to test if the treatment was effective. A therapist was present in the room with Molly at all times. Bids for attention were ignored. In all conditions where items were present, the therapist delivered praise and/or switched items once every 5 min.

Baseline

The therapist in the room did not interact with Molly. No items were present during baseline sessions. Baseline followed the same procedures as the FA ignore condition.

Single item

During the single-item treatment, Molly had access to the item with the highest engagement and lowest SIB from the competing stimulus assessment, which was the BopIt. The item was placed on the table away from Molly before the start of the session. Before the session, the therapist told Molly, “On the table is the BopIt.” With light physical guidance, the therapist directed Molly to the BopIt on the table. Molly engaged with the item for 10 s. The therapist placed the item back on the table and placed Molly’s hands in her lap. At the start of the session, the therapist told Molly she can play with the BopIt or she did not have to. Every 5 min, the therapist delivered praise (e.g., “Good job playing with the BopIt”) contingent on engagement or provided a contingency review if the client was not engaged with the item.

Multiple items

The BopIt, stuffed animals, and squeeze ball were used in this condition. All three items were placed on the table in front of Molly. Before the session began, the therapist used light physical guidance to guide Molly’s hand to the first item. After engaging with the item for 10 s, Molly’s hand was guided to the next item where she received 10 s of access to the item. The process continued for the last item. All items were placed back on the table within arm’s reach of Molly and Molly’s hands were placed in her lap. At the start of the session, the therapist told Molly she can play with the items or did not have to. Every 5 min, the therapist would deliver attention to Molly (e.g., “Good job playing with the ___.”) contingent on engagement. Also, a contingency review was stated for the other items she could play with (i.e., “Remember you can play with the ___”).

Alternating items

The same items used during the multiple items condition were used for this condition. Before the session began, the therapist gave one item to Molly and allowed her 10 s of access with the item. The process repeated for the other two items. At the start of the session, one item was randomly placed on the table. The therapist guided Molly’s hands to where the item was to show her and then reset her hands back to her lap. To start the session, the therapist told Molly she could play with the item or she did not have to. During the session, Molly had access to the item for 5 min. After 5 min, the therapist told Molly “Good job playing with the____. Here is the ___.” The therapist took the item from Molly and placed a different item on the table. The 5 min rotation of items continued until the session ended.

Results

Figure 1 displays the percentage of intervals in which SIB occurred during a screening assessment and FA. During the screening assessment, three ignore conditions were conducted. SIB occurred at high rates (mean of 60% of intervals) and was on an increasing trend, indicating a positive automatic function. To confirm these results, and to rule out possible social functions, a traditional multielement FA (Iwata et al., 1982/1994) was conducted. During the traditional FA, Molly engaged in elevated levels of SIB during the escape and attention condition, with SIB occurring in a mean of 14% and 3% of intervals, respectively. There was a lack of responding in the play condition with SIB occurring in none of the intervals. We hypothesized the items that were utilized in the play condition were competing with SIB. Therefore, a reversal design was utilized to evaluate this hypothesis. We alternated between play with items and play with no items. When items were removed during the play condition, there was an increased level of responding, SIB occurred in a mean of 23% of intervals. When the condition was reversed to include items in the play condition, responding decreased with SIB occurring in a mean of 2.5% of intervals. A final reversal was conducted and as results we saw an increase in SIB with a mean of 51% of intervals when items were removed from the play condition. Through this FA, the results of the screening assessment were confirmed. We identified a positive automatic function of SIB for this participant.

Figure 1.

Results of the FA for Molly.

Figure 2 displays the results of the CSA. SIB and engagement with items are displayed as a mean percentage of intervals. There were elevated levels of SIB in the control condition with SIB occurring in a mean of 61% of intervals. SIB decreased in all test conditions. SIB was the lowest in the conditions including the items squeeze ball, stuffed animals, and BopIt with SIB occurring in a mean of 4%, 2%, and 1% of intervals, respectively. Engagement was also the highest in the conditions with the items squeeze ball, stuffed animals, and BopIt with a mean percentage of engagement of 98%, 99%, and 99%, respectively. Due to the low levels of SIB and high levels of engagement, these items were selected for the treatment evaluation.

Figure 2.

Results of the competing stimulus assessment for Molly.

Figure 3 displays the results of the treatment evaluation. We observed high levels of SIB in the baseline condition, with SIB occurring in a mean of 65% of intervals. We then moved to the treatment evaluation of single, multiple, and alternating items. The results showed low levels of SIB in all conditions with a mean percentage of intervals with SIB occurring at 1.5%, 0.2%, and 1.1%, respectively, during the first test phase. All conditions implemented in the first intervention phase were highly effective at reducing the percentage of intervals with SIB. A reversal to baseline was conducted and SIB increased to a mean of 31% of intervals. We conducted a reversal to evaluate single, multiple, and alternating items. The results showed a decrease in SIB in all conditions with a mean percentage of intervals with SIB occurring at 2.7%, 17.3%, and 7.5%, respectively. All conditions implemented in the second intervention phase were effective at reducing the percentage of intervals with SIB relative to baseline; however, the data showed larger differences in the percentage of intervals in which SIB occurred between the treatment conditions relative to the first intervention phase. In this intervention phase, the single-item conditions resulted in a differentially lower percentage of intervals in which SIB occurred relative to the alternating and multiple items conditions. The mean percentage of intervals of SIB in all test conditions for single, multiple, and alternating items was 2.1%, 11.7%, and 5.4%, respectively. This may have been due to habituation occurring with other items and not the BopIt. Based on the results of the treatment evaluation, we identified the single-item condition (BopIt) as the most effective at reducing SIB when compared with alternating items or having multiple items available simultaneously.

Figure 3.

Results of the treatment evaluation for Molly.

Discussion

To summarize, we conducted an FA and determined Molly’s SIB was maintained by automatic reinforcement. We then conducted a CSA to identify a hierarchy of items based on how well they competed with SIB. Next, to treat SIB, we included the items that competed best in different presentation formats (i.e., single item, multiple items, and alternating items) involving noncontingent access. We found noncontingent access to a single item was the most effective presentation format to decrease SIB (i.e., skin picking). Results from this study demonstrate three important contributions to the literature on reduction of challenging behavior among individuals with ASD. First, we replicated effective intervention for automatically maintained problem behavior informed by the results of a CSA. Levels of skin picking were much lower across all formats of treatment as compared with baseline.

Second, we replicated and extended previous procedures evaluating the format in which noncontingent stimuli are effective. We included a CSA prior to treatment evaluation to inform a treatment consisting of competing stimuli being delivered noncontingently. Our results differed from Deleon et al. (2000) in that access to a single stimulus reduced skin picking more than access to multiple or rotating stimuli. This difference might emphasize the need of conducting a CSA before intervention. It also might suggest that although items may be preferred, they may not compete with behavior as well as other items. Furthermore, the degree at which effects of habituation occur may be idiosyncratic to the individual and the stimuli present.

Third, we also extended previous work by increasing the duration of sessions in our CSA based on caregiver input. Few studies have included sessions with durations of 10 min or longer. This extension demonstrates the evaluation of effectiveness of competing stimuli at a longer duration, and added social validity to the intervention through caregiver input.

There are a number of limitations to include. First, although we decreased skin picking, we did not identify a new, more appropriate replacement behavior. That is, we did not directly increase our participant’s repertoire of socially relevant responses to compete with skin picking. Second, we did not control for attention provided by therapists during the treatment evaluation. Previous studies did not specifically state if they included therapist attention. The attention provided by our therapists when delivering items could have served as a social reinforcer limiting the conclusions we can draw about the effect of the competing stimuli alone. However, it is important to note that our FA showed her skin picking to be maintained by automatic reinforcement and not socially-mediated reinforcement. Third, the participant was exposed to one item twice, and the remaining two items once in each session of the alternating condition. This was due to session duration and alternation schedule. There were small differences in how well the top three items competed with skin picking in the CSA, nonetheless one may have competed better than the others. Fourth, we did not select items that matched the stimulation Molly might have been experiencing from the skin picking. Previous studies have used items with hypothesized matching stimulation to reduce automatically maintained challenging behavior (e.g., Piazza et al., 2000; Rapp, Cook, McHugh, & Mann, 2017). Selecting items with matched stimulation may have had a greater effect in decreasing levels of SIB across all formats. Fifth, we did not complete a systematic evaluation to determine at what point habituation might occur for each stimuli. It is possible that the length of engagement for our sessions (i.e., 20 min) was not sufficient to truly measure whether the effects of habituation were prevented. Furthermore, only a single stimulus (i.e., BopIt) was chosen for all single-item conditions rather than evaluating the three stimuli that were selected for the treatment evaluation one at a time. It is possible that our results indicate that the BopIt was most effective as a competing stimulus, not that the single-item conditions were more effective than the multiple or alternating items conditions. A final limitation is that although we conducted 20 min sessions based on caregiver input, in all conditions there was a therapist interaction every 5 min, so addressing the caregiver’s concern for 20 min of independent safe play was not directly evaluated.

Future research should investigate the rate at which habituation occurs in CSAs for specific items and specific participants. There is evidence to suggest specific classes and durations of high- and low-tech items influence preference and reinforcing efficacy (Hoffmann, Samaha, Bloom, & Boyle, 2017). It is possible that our results were due to our selection of items from a specific class and the duration at which we allowed access to the items. Furthermore, future research should investigate the use of a systematic evaluation to determine at what point habituation might occur for various stimuli. In addition, although parametric duration of CSA and associated effects on the reduction of behavior have been conducted (DeLeon, Toole, Gutshall, & Bowman, 2005), further research on social validity of these durations may be necessary.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Author Biographies

Casey J. Clay, PhD, BCBA-D, is an assistant professor in the Department of Health Psychology at the University of Missouri. His research interests include reduction of problem behavior, stimulus preference assessments, and behavioral skills training.

Annie M. Clohisy, MEd, BCBA, received her master’s degree from Vanderbilt University and was a clinician at the Thompson Center for Autism & Neurodevelopmental Disorders at the time of this study.

Alexandra M. Ball, MEd, BCBA, was a graduate certificant student in Applied Behavior Analysis at the University of Missouri and is now a clincian working at KidsTLC.

Aqdas F. Haider, MS, is in the graduate certificate program in Applied Behavior Analysis, and is a doctoral candidate in the Department of Educational, School, and Counseling Psychology at the University of Missouri.

Brittany A. Schmitz, is a student in the Applied Behavior Analysis graduate program in the Department of Health Psychology at the University of Missouri.

SungWoo Kahng, is an associate professor and chair of the Department of Health Psychology. He is also director of the Applied Behavior Analysis graduate program at the University of Missouri.

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