Study 1: A behavioral intervention of food refusal in adults with developmental disabilities
Feeding disorders are common in both children and adults with DD. Among the most serious of these is the total refusal to consume food and liquid, which may present a life-threatening or severely debilitating condition. The evidence base for interventions for adults with DD and food refusal is severely limited or lacking to my knowledge. One notable exception is a study by Kitfield and Masalsky (2000), who treated a woman aged 22 using a behavioral intervention consisting of negative reinforcement in the form of escape from food as well as to other areas, which resulted in impressive weight gains during treatment and follow-up. The lack of empirically supported treatment for food refusal in adults with DD may be because food-related issues usually have an early onset and are, therefore, more often diagnosed and treated in children. Additionally, some treatments may be viewed as more invasive when applied to adults. For example, escape extinction is the most empirically supported treatment component for food refusal and selective eating among children with DD. However, implementing escape extinction in an adult may be ethically questionable because of its invasive nature, which is practically challenging or dangerous, especially when other problem behaviors are present.
In a study by Hagopian et al. (1996), total food and liquid refusal in a 12-year old boy with autism was treated with backward chaining, fading, and activity reinforcement, which successfully resulted in drinking from a cup generalized to his living unit. Fading and differential reinforcement may have an ethical and intuitive appeal when treating food and liquid refusal in adults with DD and may therefore be accepted by caregivers and adults with DD. This is because it involves gradual re-introduction of oral intake and the use of positive reinforcement. In addition, research has demonstrated that stimulus fading may render escape extinction unnecessary. Therefore, there is a need to extend the use of such procedures to adults with food and/or liquid refusal.
Study 2: A behavioral intervention of slow eating in adults with DD
Individuals with DD often require considerably more time to complete tasks of daily living than their neurotypical peers do. When slow responding becomes excessive, it may be a barrier in daily living as self-care, and finishing meals in time before scheduled events may lead to missed activities or services, family stress, and logistical challenges. Such slowness has been hypothesized to result from neurological impairments causing a slow motor response, a secondary symptom of obsessive compulsive disorder, or as a primary feature, an operant modifiable by its consequences.
Slow responding has been the subject of three empirical investigations in the behavioral literature, with two children and one adult. In all cases, the researchers utilized positive reinforcement to accelerate slow responses. Fjellstedt and Sulzer-Azároff (1973) used a differential reinforcement of low response latencies (DRL) for the following five different types of instructions to perform tasks, resulting in a substantial improvement in the speed of response. Tiger et al. (2007) increased the slow response of an adult male with Asperger's syndrome with a DRL, which resulted in a clinically significant increase in the response to two tasks. Girolami et al. (2008) utilized differential reinforcement of high rate (DRH) to increase the rate of independent bites by a child participant with ADHD and several medical issues. This procedure results in an increased rate of self-feeding. We plan to systematically replicate a DRH procedure for adults suffering from slow-feeding difficulties, with modifications involving the use of changing criteria for reinforcement.
Study 3: A behavioral treatment of debilitating stereotypy in adults, comparing response interruption with redirection and chained schedules
Stereotypy refers to behavior topographies in individuals with autism and DD that are invariable, repeating, meaningless, or out of context. These topographies can present a considerable amount of distress for the individuals and their family members as it may be a barrier for habilitation, independent living and learning. Because the majority of researched stereotypi in individuals with autism have automatic reinforcement as its function, a new strategy for functional analysis (FA) of stereotypi involves pre-treatment screening for automatic reinforcement.
Function-based treatment of automatically maintained stereotypy is particularly challenging because reinforcers are not easily manipulated or extinguished. Physically preventing stereotypi in adults may be practically challenging, especially because it may elicit emotional or aggressive behavior. For example, response blocking has been documented to reduce automatically maintained pica but increase aggressive behavior. Research has shown that when stereotypi are both blocked and redirected toward an ongoing behavior, aggressive behavior does not increase. A treatment procedure for automatically maintained stereotypi, called response interruption with redirection (RIRD), involves interrupting each instance of stereotypi and redirecting behavior to an ongoing task or appropriate behavior. RIRD has received extensive empirical support from child participants for reducing stereotypi, but has not been researched in adults. Another treatment procedure that has recently received increased attention in behavioral literature is chained schedules (CS), often contrasted with multiple schedules (MS), both of which are different procedures for programming stimulus control over stereotypi. MS involves the use of discriminative stimuli (SD/S+ vs. SΔ/S-) for different treatment components, where in one phase, all instances of stereotypi are blocked in the presence of S- (e.g., at red card), while in the presence of S+ (e.g., a green card), all instances of stereotypi are allowed. However, no reinforcement contingency was programmed. On the other hand, CS also involves blocking stereotypi in the presence of S-, but providing contingent access to stereotypi from one component (red card/ S-) to the other (green card/ S+) contingent upon the absence of stereotypi. Therefore, alternation between the two components depends on the performance of one of the components. When compared to MS, most empirical demonstrations favor CS, both in terms of the reduction of stereotypi and an increase in adequate item engagement. As pointed out by Sloman et al. (2022), autism advocates view access to "stimming" as a means for individuals with autism to self-sooth and regulate emotions, and may therefore be more preferred. However, the CS procedure is more complicated than the RIRD procedure (see below). In addition, the RIRD does not program a differential reinforcement of alternative responses. CS may, therefore, be preferred by adults and caregivers in that it targets increasing adaptive responses. However, some treatment settings may favor RIRD over CS because of its ease of implementation. An interesting question is whether caregivers and clients provide different answers to these questions. Therefore, the current research question concerns a) the efficacy of RIRD as compared to CS, both in terms of behavior reduction and treatment duration, b) client vs. caretaker preference for either treatment procedure, c) extension of these two empirically supported treatments to adult participants, and d) generalization to the most problematic settings in daily life.
\[PP2\]Hope this clears it up
