Blending Stimulus Fading Procedures with Forward Chaining to Address Treatment Resistance in an Adult with an Autism Spectrum Disorder

Abstract

The following paper details the implementation of a program to address the high-risk physical aggression and property destruction behavior of an adult male with an autism spectrum disorder (ASD) and severe aggressive behavior. A task analysis (TA) and forward chaining were combined with a stimulus fading procedure to allow the subject to be able to participate in van rides when prompted with no displays of aggressive or self-injurious behavior. A follow-up probe completed at 1-year post intervention demonstrated the maintenance of the gains that were made during treatment.

Appendix

The study took place in a community-based home that was located in a residential neighborhood in a large Midwestern town. The residence was equipped with three bedrooms, two bathrooms, and separate kitchen and dining room areas. The residence was staffed 24 h a day, 7 days a week. The study was conducted in a company van that had adjacent driver and passenger-side seats, a second row of adjacent captain’s chairs seats, and an extended rear seat.

Randy was a 23-year-old male diagnosed with an autism spectrum disorder. The subject displayed high frequencies of aggressive behavior, property destruction, and self-injurious behavior that were so dangerous that an analogue functional analysis was not feasible. Systematic evaluation of the function of these behaviors was conducted via the functional assessment instruments the Questions about Behavioral Function (QABF) and Functional Assessment Screening Tool (FAST) (Iwata et al. 2013). These assessments indicated that his aggression served an escape function.

Intervention strategy—Prior to the study, Randy had lived with his mother for 22 years and had only traveled with family members in their vehicles. Therefore, the familiar stimuli of his mother, the first author, and the house manager were utilized to make the van ride less aversive and were faded out as the program progressed.

Additionally, Randy wore a weighted vest that was previously introduced by previous team members and encouraged by family members. It was retained due to his routine of wearing it prior to vehicle rides with his family. He displayed no resistance to wearing the vest when prompted.

Structure was added with a 10-step task analysis (TA) that was constructed and validated by the first author. Each step was forward chained and reinforced with his viewing a preferred video once he performed the terminal step of walking into the building where the day program was located. The initial prompt was the S^D to follow the steps of the TA with each successive step an S^D for the next step.

The dependent measure was the percentage of successful van trips, defined as the number of completed steps on the TA for van travel (see Table 1). Each of the steps of the TA was scored based on their occurrence or nonoccurrence for a given day. The same staff member initiated the prompting sequence and scored the TA data sheet each day. The first author was present during each of the steps of the fading procedure and scored the steps along with the staff member that had initiated the prompting sequence. Reliability data were taken for 100 % of the sessions utilizing the fading protocol, 30 % of the withdrawal phase, and 30 % of the subsequent sessions. Reliability ranged from 90 to 100 % with an average agreement score of 97 %. Inter-observer reliability was calculated utilizing the following formula:

$$ \frac{\#\ \mathrm{of}\ \mathrm{responses}\ \mathrm{observed}}{\#\ \mathrm{total}\ \mathrm{possible}\ \mathrm{appropriate}\ \mathrm{responses}}\times 100 $$

An ABAB withdrawal design was used to demonstrate the efficacy of the treatment package employed in the study. A specific prompting sequence was followed whereby Randy was prompted to get ready to attend his day program during all of the phases of the study. During the stimulus fading and chaining conditions, the TA was scored and staff were trained on the implementation of each of the steps of the behavioral chain of getting ready for the day program as outlined in the TA.

A prompting sequence was initiated with Randy that involved an initial verbal prompt, “Randy, get up, it is time to go to the day program.” This verbal prompt was repeated if he did not respond within 30 s to the initial prompt. This sequence continued for 15 min until he either refused to participate or complied. The same prompting sequence was provided during all of the sessions during baseline. The prompts were repeated if he refused, but there were no other consequences that were provided after the provision of the verbal prompts. Refusal to attend or comply were treated the same in terms of staff’s response.

Fading protocol—The staff initiated the same verbal prompting sequence as described in the baseline phase on each day that the intervention was in place. The forward chaining procedure (see Table 1) was followed with each step in the TA being scored and subsequent steps being initiated as soon as the prior step had been accomplished. The primary difference that took place was the inclusion of familiar stimuli in the form of his mother and the first author. Both of these individuals assisted with the prompting and rode with him in the van once he was able to tolerate that portion of the chaining procedure. Once Randy was in the van, he was seated with the same seating configuration daily as outlined in the fading protocol (see Fig. 2). The staff that were present in the van were faded on successive days as he was transported to the site of his day program (see Fig. 2).

Fig. 2

Each of the steps of the hierarchy was faded on successive days as indicated by the individual steps outlined above. Each of the steps from F1 through F5 was systematically faded on a daily basis until only step F5 was being followed on a daily basis

The return to baseline phase was identical to the baseline phase described above. The same staff member was identified to initiate the prompting sequence. The staff member did not utilize the chaining procedure described above. Randy was given a verbal prompt to prepare to get up and get ready to go to his day program. The prompts were repeated if he refused according to the same schedule as described in the initial baseline phase, but there were no other consequences that were provided after the provision of the verbal prompts. Refusal to attend and comply were treated the same in terms of staff’s response to his compliance or refusal to participate.

The follow-up phase was identical to the baseline phase described above. The same staff member was identified to initiate the prompting sequence. The prompts were repeated if he refused according to the same schedule described in the initial baseline phase, but there were no other consequences that were provided after the provision of the verbal prompts.