Pivotal Response Training (PRT) is, “a method of systematically applying the scientific principles of applied behavioral analysis (ABA) to teach learners with autism spectrum disorders (ASD)” (Wong, 2013). It was originally developed by Drs. Lynn Koegel and Robert Koegel of the University of California, Santa Barbara, Koegel Autism Center through the publication of their seminal article “A natural language teaching paradigm for nonverbal autistic children” (Koegel, O’Dell and Koegel, 1987). According to Koegels, PRT is, “used to teach language, decrease disruptive/self-stimulatory behavior, and increase social, communication, and academic skills” (Koegel Autism Center, 2014).  The current name pivotal response treatment is a registered trademark of the Koegel Autism Center. However, there are many other names for the same method, including pivotal response training, pivotal response therapy, pivotal response intervention, and even National Language Paradigm (McClelland. 2016).

Pivotal Response Treatment is a child directed, naturalistic teaching strategy, unlike other structured models, like Discrete Trial Training (DTT). In the PRT model, learning opportunities are determined by the child’s interests with emphasis on natural reinforcers, rather than contrived reinforcers. The Koegels, and those who follow PRT, believe natural reinforcers are a stronger form of reinforcement than contrived reinforcers (Koegel Autism Center, 2014). The Koegel Autism Center’s website offers resources of over 200 peer reviewed journal articles and 30 books and manuals based on Pivotal Response Training. Since PRT is often termed as lifestyle, rather than a teaching method, as it requires minimum of 25 hours per week to be successful, the advocates of PRT emphasize that it should not be done solely by professional interventionists; it as an important component of PRT that it is  recommended that family members continue the process at home for generalization and to optimize its effects.

Pivotal Response Training targets four pivotal areas of a child’s development, which are identified as motivation, responding to multiple cues, self-management, and self-initiation. By focusing on pivotal areas, PRT produces improvements across other areas of social skills, communication, behavior and learning. These learning variables have multiple components and may overlap when being taught. If a child cannot fully participate in the learning process (i.e., sit still, follow directions, etc.), then they will have a harder time mastering skill such as self-management or self-initiations (McClelland, 2016).

Since responding to multiple cues teaches the child how to discriminate between more than one stimulus and significantly enhances learning and generalization to other areas of development, PRT states response to multiple cues as an important pivotal response by aiming to reduce stimulus over selectivity in children with ASD and teaching them to respond to multiple relevant cues. (Koegel, Koegel, Shoshan and McNerney, 1999). This is done by scheduling the delivery of reinforcement, as each cue is added or response required, and increasing the criteria required, for example, big red car vs. car (Vismara and Lyons, 2007).

The second important pivotal area that produces prominent gains in a child’s development in other areas of learning is motivation. Motivational procedures can be used to teach communication, self-help, academic skills, social skills, and recreational skills (Koegel, Koegel, Shoshan and McNerney, 1999). The earliest PRT package developed by Koegel in 1987 was based on motivation, in which the research established that by adding specific motivational variables, such as child choice and natural reinforcers, the children were far more motivated and happier to learn in a play-based session, which also resulted in less disrupt behaviors (Koegel. O’Dell and Koegel, 1987).

The third area of pivotal learning is self-management. “Self-management is defined as individuals discriminating and self-initiating their own appropriate behavior and then self-reinforcing or self-recruiting reinforcement for their own appropriate behavior” (Koegel, Shoshan and McNerney, 1999). By teaching a person to self-manage their behavior, and we are training them to be independent within other environment and situations, with minimum support from intervention provider.

A final important pivotal area for growth for a child with Autism is self-initiation. Koegels define self-initiation as an individual beginning a new verbal or nonverbal social interaction, self-initiating a task that results in social interaction or changing the direction of an interaction. Self-initiating is a very important skill that opens the world to the child. Be it initiating a request for cookie or asking a question, self-initiating increases the autonomy of a child, and makes the world outside any specific teaching context.

Official PRT Training

Pivotal Response Training is trademarked by the Koegel institute in UCSB and there is an official PRT training program (Koegel Autism Center, 2014). This is a long-distance learning program, allowing people from anywhere in the world to get certified. There are five levels of training that everyone can participate, depending on what services they plan to provide. The first level is a basic introduction to PRT including the research and methodology. The second level provides instruction on how to implement strategies. Level three provides information about generalization and how to use PRT for more than one child at a time. Level four is an advanced level that uses PRT to teach skills such as self-initiations, self-management, and facilitating social interactions. The fifth and final level is designed to teach participants to become PRT trainers, allowing them to teach others, the skills they have learned (Koegel Autism Center, 2014).

History of Pivotal Response Treatment

During 1960’s behavioral interventions for ASD focused on consequences through highly intensive and structured trials, where adult-chosen stimuli were repeatedly presented to teach target behaviors. (Lovaas, Berberich, Perloff and Schaeffer,1966). This was the start of Discrete Trial Training (Hewett, 1965; Lovaas et.al.1966; Sloane and MacAulay, 1968; Wolf Wolf, Risley and Mees, 1964) which was the first evidence-based teaching method done in structured, isolated environment, one on one by trained therapists in which the child received contingent rewards or punishment as consequences. (Lovaas et.al., 1966). Some target goals addressed by these studies were imitation training and social behavior, speculating that if those areas could be improved, it would make learning by children with ASD as close to typically developing children. Although some ground-breaking results were achieved by these studies, the participants did not generalize the learned skills to another person or/and environment and most importantly the learned skills did not contribute to other areas of learning.  (Lovaas, Schaeffer and Simmons, 1965; Lovaas et. al.,1966). Therefore, the results of these studies implied that imitation and social behaviors were not pivotal skills for ASD, which prompted Dr. O. Ivor. Lovaas and a team of his graduate students to identify Pivotal areas of development by children diagnosed with ASD (Lovaas, Koegel, Simmons and Long, 1973). Two of PRT’s original developers, Dr. Robert L. Koegel and Dr. Laura Schreibman, share early publications that led to the development of DTT for example; Lovaas, Koegel, Simmons and Long, 1973; Lovaas, Schreibman and Koegel, 1974; Lovaas, Varni, Koegel and Lorsch, 1977; Russo, Koegel and Lovaas, 1978; Varni, Lovaas, Koegel and Everett, 1979.

While still using the discrete trial training method for teaching individual target skills, Lovaas’s students started the search for a teaching method that was not as laborious and time-consuming and would contribute to widespread improvement in children’s overall learning. This led to the Koegel and Egel (1979) revolutionary study, “Motivating Autistic Children” about motivation as a pivotal skill for children with Autism in which they suggested that reinforcing attempts keeps the child motivated to learn. They found that children learned faster when they experienced a steady rate of success and the learning experiences were much more pleasant for the therapist and families.

Henceforth, during the 1980’s several studies researched on individual components of PRT; “Motivating autistic children through stimulus variation” (Dunlap, Koegel and Robert, 1980), “The influence of child-preferred activities on autistic child’s social behavior” (Koegel, Dryer and Bell, 1987) and “Response reinforcer relationships and improved learning in autistic children” (William Koegel and Egel, 1981).  These ground-breaking discoveries led to research on the development of the powerful motivational package that would eventually be named as PRT. The goal of the earliest study “A Natural Language Paradigm for teaching non- verbal autistic children” (Koegel, O’Dell and Koegel,1987) was to show that the DTT could show some powerful success if specific motivational variables would be incorporated such as child choice of stimulus materials and use of natural reinforcers. This was the first attempt to teaching in naturalized environment thus the name Natural Language Paradigm (NLP) was the inception of Pivotal Response Treatment (PRT).

Essentially, NLP attempted to improve upon traditional discrete trial methodology for teaching language, and specifically attempted to address concerns with generalization and maintenance of treatment gains while simultaneously improving spontaneous speech. (Koegel, O’Dell and Koegel,1987). Later, since this approach positively affected many areas of beyond speech, the name Natural Language Paradigm was changed to Pivotal response Treatment (Koegel and Koegel, 2006). Along with the emergence of positive behaviors such as children’s happiness, enthusiasm, and interests. by adding motivational strategies, the researchers also started noticing a decrease in disruptive behaviors (Koegel, Koegel and Surratt, 1992; Vismara and Lyons, 2007; Schreibman, Kaneko and Koegel, 1991).

Another critical pivotal area of development researched by early studies was social initiations and question asking. The theory behind this was that if children with Autism could be taught “self-initiate” by asking questions it would open the world to them. A study by Koegel, Camarata, Koegel, Ben-Tall and Smith in 1998 showed that children with Autism could be taught to ask questions which led to subsequent teaching interaction from others in the natural environment. This extended to a study in which questions were specifically targeted to verbs (Koegel, Carter and Koegel 2003) and prepositions (Koegel, Koegel, Green-Hopkins and Branes 2010).  Therefore, with the comprehensive application of PRT, it was found that when self-initiation occurred as a pivotal skill in children with Autism, they were observed to have a much better life s young adult. (Koegel, Koegel, Shoshan and McNerney, 1999). In another successful study it was observed that with self- initiation, students with severe autistic disabilities could learn to use a self-management treatment package to reduce their stereotypic behavior. (Koegel and Koegel, 1990).

The scientific research solidly shows that acquisition of pivotal skills is essential for accelerating the learning curve for children with Autism. The Koegel foundation has published studies ranging from single-subject design to group statistical designs to qualitative designs and clinical replications have been conducted from the early inception of PRT till date to validate the science behind PRT. One novel component that PRT has embodied is the intensive involvement of parents in the treatment process. From the early days of PRT to date educating parents to implement PRT at home with children has been a priority. Laski, Charlop and Schreibman, (1988) used the principles of PRT (then called NLP) to train parents to successfully increase child’s speech. A recent study has been done by Coolican, Smith and Byrson, (2010) to parents of preschool children to check treatment fidelity of the PRT procedures implemented by parents. Another aspect that PRT has always advocated as being vital for early language and social development of prosocial behaviors and social competence through increasing social skills play skills and peer interaction. (Pierce and Schreibman, 1995).

The researchers behind PRT have been always been rigorously trying to modify with critical analysis to deliver a model that embodies the best practices in ABA. Some recent implications regarding generality of PRT as an intervention to widespread population of Autism have been addressed by two large scale studies which showed that it was feasible to implement PRT throughout the entire province of Nova Scotia Canada (Bryson et. al, 2007; Smith et. al, 2010). The data showed once trained, treatment providers could teach parents and other interventionists in a “trainer of trainer” model with a fidelity of implementation over time. Furthermore, this study also showed that PRT is an effective model to be delivered over telehealth services, to many children who lived in very remote areas without access to clinics and centers. Another, recent studies by Lei and Ventola, (2017) focuses on the recent emerging neuroimaging evidences supporting PRT, offering current perspectives on the importance of interdisciplinary research to help clinicians better understand how PRT works and predict who will respond to PRT.

Philosophical foundations of Pivotal Response Treatment with Applied Behavior Analysis

“Applied Behavior Analysis is a science in which tactics derived from the principles of behavior are applied systematically to improve socially significant behavior and experimentation is used to identify the variables responsible for behavior change” (Cooper, Heron, Heward, 2018 p. 40). Pivotal Response Training (PRT) is a method of applying the scientific principles of applied ABA to teach learners with autism spectrum disorders (Koegel, O’Dell, Koegel, 1987). PRT relies on operant teaching principles and has been used to target a wide range of deficits, including social skills and communication (Handleman & Harris, 2001). PRT embodies the philosophy of Behavior in many important aspects. First, it gives the conceptual framework which means that the principles of PRT align with that of Operant conditioning (Skinner, 1953). Secondly, PRT embodies the 7 Dimensions of ABA as proposed by Bear, Wolf and Risley in their seminal paper “Some dimensions of Applied Behavior Analysis” (Bear, Wolf and Risley, 1966), offering an effective intervention package for behaviors that are socially significant and pivotal for human development. Moreover, PRT is also indebted to applied behavior analysis for its foundations from the law of effect (Thorndike, 1927), the concept of three-term contingency; stimulus-response- reinforcing consequence (Skinner, 1969), the concept of establishing operations (Michael, 1982) and the notions of generalization and maintenance (Barton, 1979) .

The foundations of Pivotal Response Treatment come from philosophical roots of ABA which is the “law of effect” coined by Thorndike, 1927; the law of effect states that behavior is a consequence of its function. Simply stated that the occurrence of a behavior is directly related to the consequence that follows it. Thorndike suggested that responses closely followed by satisfaction will become firmly attached to the situation and, therefore, more likely to reoccur when the situation is repeated. Conversely, if the situation is followed by discomfort, the connections to the situation will become weaker, and the behavior of response is less likely to occur when the situation is repeated. Likewise, Skinner’s three-term contingency, also an extension of Thorndike’s law of Effect reflects in the foundations of pivotal response treatment. The three-term contingency – also referred to as the ABCs of behavior (antecedent-behavior-consequence) illustrates how behavior is elicited by the environment and how the consequences of behavior can affect its future occurrence. In the PRT model, the therapist provides a prompt, waits for a child to respond and then gives the consequence. Since PRT is based on a motivational package, the reinforcers used are natural and directly related to the target behavior which produces faster and more generalized learning. (Skinner 1954, 1986 in PRT Pocket guide).

An important criterion for judging the adequacy of research and practice in applied behavior analysis is by aligning it with Bear Wolf and Risley’s 7 dimensions of Applied Behavior Analysis published in 1968. (Cooper page 36). Bear, Wolf, and Risley in their seminal paper, “Some Current Dimensions of Behavior Analysis” laid out “seven self-conscious guides to behavior analytic conduct” that stand functional and current (Bear et. al. 1987, p. 319). These interconnected dimensions are, applied, behavioral, analytic, technological, conceptually systematic, effective and generality. It is incumbent to assess any researched based intervention procedure such as Pivotal Response Treatment to be aligned strongly with the 7 dimensions of Applied Behavior Analysis.

Bear et. al state that a study to be “Behavioral”, it must measure observable behavior that needs improvement as well as takes into count the behaviors of all the individuals that are part of the study. PRT embodies this dimension effectively in a way that it targets behaviors pivotal for development as well as observable and measurable. Koegels write in their book “The PRT Pocket Guide” that the first step towards making data collection easy is to identify specific target goals, for example, for increasing communication the measurable and observable target goal would be, increase the correct use of past tense, increase ability to accurately recall personal past events and increase the ability to maintain eye contact during social conversation. (p 167).

The second dimension as proposed by Bear et. al is that research must be “Applied” by making efficiency improvements in people’s lives by targeting behaviors that are socially significant for a change. PRT’s foundation is based on targeting pivotal skills that are essential for growth in all areas of development. PRT is based on targeting pivotal areas of motivation, self-initiation, self-management and response to multiple cues which leads to large collateral changes in other untargeted areas of learning that improve the quality of life. (Koegel et. al. 1995)

A study in ABA is considered “analytic” when the experimenter has demonstrated functional control between the dependent variable and the independent variable (Bear et.al. 1968). Simple stated, the change in behavior is caused by manipulating antecedents or consequences. The studies done in PRT are based on increasing child’s motivation to learn by manipulating response- reinforcer connection thus demonstrate functional control. PRT also suggests that along with reinforcing correct responses, a child should also be reinforced (comparatively less) for attempts to learn a task so that the motivation to learn is also reinforced.

Perhaps the one dimension of ABA as proposed by Bear Wolf and Risley that aligns strongly with the components of PRT package is “Generality”. A behavior change has generality if it can be observed in environments and people other than it was implemented and contributes to other behaviors not directly targeted.  One of the foundational components of PRT is that the treatment is done is naturalized everyday setting as a result of which the behaviors learned are effectively transferred and generalized to other environments, with other people and to other behaviors.

Bear, Wolf and Risley strongly proposed that the procedures used in an ABA study should be “conceptually systematic” meaning that the procedures for changing behaviors should be derived from the principles of science of behavior. They provided a strong rationale for this saying if research has a solid theoretical base, it will be more effective for consumers to derive other similar procedures. This also impacts dissemination of ABA being meaningful and empirical rather than just a bag of tricks. PRT presents itself as being conceptually systematic as the intervention procedures are based on operant conditioning principles. The procedures established by PRT studies are rooted with three-term-contngency where the target behavior is strengthened by the contingency that follows it.

For a research to be “Effective”, the behavior change must produce meaningful change in subject’s life to a practical degree. Bear et. al also revisited the dimension of effectiveness in their later paper establishing that not only the behavior targeted should bring noticeable changes for the reasons the behaviors were selected but must also contribute to an overall change towards other important skills. For example, a goal to teach a child to request should contribute towards overall communication. The Autism Speaks website states that more than 20 studies suggest that   PRT improves communication skills in many (though not all) children who have autism. Also, a 2017 review of brain imaging studies showed evidence that PRT improves brain activity associated with sociability and communication (Lei and Ventola, 2017).

Lastly, the seventh dimension by Bear, Wolf and Risley is that a study in ABA should be “technological” in description such that it can easily be replicated by any other behavior change agent. Although, PRT studies offer operationally defined target behaviors, however, in some cases when the behaviors are more relative for example initiation or motivation it is challenging to provide technologically solid definition of target behaviors which are easily replicated by therapists and parents. Koegels address this challenge in their book, “PRT pocket guide” in the section of making data collection easy, stating that fidelity of treatment should be measured periodically by behavior change agents.

When aligning the philosophical foundation of ABA with Pivotal Response Treatment it is essential to relate the two with Jack Michael’s behavioral account of “Motivation” in his seminal paper “Motivating Operation” (MO) (Michael, 1993) which was derived from the Skinner’s notion of drive Skinner, 1938. In his paper Michael proposed 4 four term contingency- adding a motivational component prior to the discriminative stimuli which alters the value of the reinforcer which as a result alters the frequency of the behavior. He characterized MO into two conditions; Establishing Operation (EO) which increases the effectiveness of a reinforcer and AO which decreases the effectiveness of the reinforcer. PRT therapies are based on applying the concept of MO to motivate the child. For example, if the goal is to increase expressive language, PRT therapist would use lunch time or snack time when the child has the MO to ask for help or request for a food item. Once the child is done eating, there is an AO which means he will probably not engage in verbal response for a food item therefore the PRT therapist would follow the child’s lead and use another natural reinforcer for example, a toy that is turned off or the pieces that go with it are not available to the child so that he has the MO to request for them. Since PRT package is based on Motivation, the treatment is done with natural reinforcers which are directly and functionally related to the task.

Application of Pivotal Response Treatment Components in Early Intervention

Pivotal Response treatment is listed by the National Research Council as one of the ten recommended programs for autism and one of three scientifically researched interventions proven to be effective for Autism Spectrum Disorder. (Simpson, 2005).  Over the past 30 years, the Koegels, their graduate students, and their colleagues have published over 200 research articles in peer-reviewed journals and over 30 books and manuals that support the effectiveness of PRT. The published research has not only provided robust evidence for the effectiveness of focusing on Pivotal Skills, but also validates the critical features of service delivery. Specific research-based strategies include child choice, task variation, interspersing maintenance and acquisition tasks, rewarding attempts, and the use of direct natural reinforcers. In addition to the strategies, PRT emphasizes on treatment to be implemented in natural environments of the child (e.g., home, community, and school) and emphasizes parent education to empower family members to become agents of intervention, so that learning can be embedded across daily routines. The focus of the current chapter is to empirically validate the critical features of service delivery procedures and the motivational package that targets pivotal areas represented by Pivotal Response Treatment.

Evidence of Effectiveness of focusing on pivotal areas:

The theoretical underpinning of Pivotal Response Treatment lays on the foundation of focusing on pivotal areas of functioning which, once targeted, lead to collateral changes in numerous other areas of development. This concept is described in the literature as response covariation by Kazdin (1982), who reviewed the evidence in relation to treatment. Kazdin suggested that research has shown, for given individual, that several behaviors tend to be correlated to form clusters of responses and therapeutic changes in one response in a particular cluster are likely to affect other, unrelated response. Likewise, numerous studies have been replicated on various dependent variables that have provided empirical evidence that acquisition of pivotal skills is essential for accelerating the learning curve for children with Autism. The pioneer study (Koegel and Egel, 1987) that presented PRT as a package was done on 2 non-verbal children diagnosed with Autism, in which the behavior targeted was imitative and spontaneous child utterances. In multiple baseline designs, the researchers applied traditional analog clinical format where the therapist presented instructions, prompts, and reinforcers for correct responses for baseline condition. Then, these variables were manipulated in the PRT condition in which the motivational package was applied such that stimulus items were functional and varied, natural reinforcers were employed, communicative attempts were also reinforced, and trials were conducted within a natural interchange. Treatment and generalization data demonstrated that manipulation of these variables resulted in broadly generalized treatment gains. This was the first study done by Koegels that validated the application of PRT as a package.

Numerous studies have replicated and validated the benefits of PRT as a package for early learners for whom joint attention and social initiation is a pivotal developmental skill. A study done by Vismara et.al (2007) used a single-subject reversal design with alternating treatments to examine whether joint attention initiations for social sharing would occur as a collateral effect of applying the motivational techniques of PRT in conjunction with highly preferred reinforcers for three young nonverbal children with autism. Results indicated an immediate increase in joint attention initiations when highly preferred stimuli were incorporated within the motivational techniques of PRT. Additional findings included collateral increases in joint attention initiations toward less preferred interests, as well as improvements in the quality of interaction between the children and caregivers. A similar study has been replicated by Koegels in which modified PRT was used to assess the feasibility of rapidly increasing infant motivation to engage in social interaction. The research was done on three infants ages 4, 7, and 9 months in multiple baseline designs. Baseline data showed low and erratic levels of social behavior (avoidance of eye contact, low effect and low rate of response to name) which after applying PRT package, resulted in an immediate increase and stability of social engagement that also persisted in the follow-up visits.

Another area of development relevant to early learners diagnosed with autism is a lack of play skills. Acquisition of play repertoire is pivotal for children with autism as this important development opens doors for gains in social and communication skills. A study was done by Stahmer (1995) in which PRT was applied to teach symbolic play skills in multiple baselines across participant design. The researchers examined symbolic play, the complexity of play behavior, and creativity of play which after training improved in all participants who learned to perform complex and creative symbolic play actions at levels like that of language-matched typical peers. In most cases, the children generalized their play to new toys, environments, and play partners and continued to engage in symbolic play behavior after a 3-month follow-up period.

Recent advancements in science have made it possible to validate the positive effects of PRT on pivotal skills like communication, behavior, and social skills in young children with autism. A recent study done by Voos et. al (2012) used functional magnetic resonance imaging to identify the neural correlates of successful response to PRT in two young children with ASD. Both children showed striking gains on behavioral measures and also showed increased activation to social stimuli in brain regions utilized by typically developing children. These results suggest that neural systems supporting social perception can be acquired through the implementation of PRT.

Child Choice

Child Choice refers to incorporating stimulus materials, toys and topics in learning that are influenced by child’s preference that is purposefully identified by the instructor by following child’s lead (R.L Koegel et. al 2001). Numerous researches have established the effectiveness of this antecedent intervention; Shogren et. al (2004) examined the efficacy of the use of choice-making as an intervention for reducing problem behavior through a meta-analysis of single-subject research studies and concluded that allowing learners to choose their preferred activities is particularly important when teaching new skills.

Koegel et al (1998) identified choice making as a fundamental variable for the application of Pivotal Response Treatment by incorporating natural stimuli in learning the task. Using stimuli (activities and toys) that learners with Autism prefer increases their motivation to participate and thus the likelihood of acquiring target skills. To assess learner choice the teacher should observe the learner in a free operant environment and identify what they are engaging with. For example, if a child is observed to be playing with cars, balls, and playdoh, the teacher should include these preferred materials in learning tasks and activities.  Koegel also identified that child choice results in rapid learning when learners are offered to choose from a variety of stimulus which is varied frequently according to the child’s interest (Koegel 1995). This is important because the teacher should consider that the preferences of the child could change fairly frequently. Therefore, it is important to follow the child’s lead constantly and capitalize on their motivation to participate during learning experience (Koegel et al 1998).

In a seminal study published by the Koegels about language acquisition, it was established that allowing the child to choose from the preferred stimulus was one of the fundamental components of natural teaching condition that resulted in initial word acquisition (Koegel et.al 1987)1. The research was conducted in multiple baselines across participants design in which 2 treatment condition were compared; analog condition, which was traditional instruction followed by reinforcers or prompts and PRT condition. In the PRT condition, one of the first variable manipulated was that the instructor presented a stimulus according to the child’s selection of a preferred item from a pool of items instead of arbitrarily selecting item themselves. The result of the study was a huge success since the children had much higher rates of imitative utterances during the PRT condition. The researchers concluded that the high rate of language utterances along with successful generalization of language occurred which was due to the fact that the instructional strategy utilized a pool of items that the child was offered to the child to choose from and made accessible too.

Another study in the same year (Koegel et.al 1987) studied the results of manipulation of task variables that may influence the severe social unresponsiveness of children diagnosed with Autism. The study was conducted as a correlational analysis of three participants in a reversal design. The researchers analyzed the behavior of social avoidance and social responsiveness by manipulating child preferred items versus arbitrary activities. Results revealed a negative correlation between appropriate child-preferred activities and social avoidance behavior. Additional analyses also revealed that social avoidance behaviors would predictably decrease when the children were prompted to initiate appropriate child-preferred activities. The procedure was also pragmatic to be used in community settings to teach children to initiate child-preferred activities and also resulted in reductions in social avoidance responses even after the therapist’s prompts were completely removed.

The importance of following child’s lead was validated in a study done by Koegel et. al (2009) which compared two intervention conditions; a Naturalistic approach (which incorporated motivational variables) vs. an Analog (more traditional, structured) approach. The target behavior was correct and intelligible production of speech sounds assessed in ABA design. The result indicated that although both methods effectively increased correct production of the target sounds under some conditions, functional use of the target sounds in conversation occurred only when the naturalistic procedures were used during the intervention. One variable that was assessed as a component analysis was Choice and No Choice condition. Higher levels of disruptive behaviors occurred in the No Choice conditions, without exception that in the Choice conditions. Furthermore, No Choice phase was forced to be discontinued due to repeated requests to leave the session and task across four continuous sessions; did not occur during the choice condition sessions.

Task variation, Interspersing Maintenance and Acquisition Tasks

A fundamental motivational variable that is used in the service delivery of Pivotal Response Treatment is task variation. Task variation can be in two ways; interspersing previously learned task (maintenance trials) with acquisition trails (Dunlap et.al. 1984) and varying stimulus items and reinforcers during learning interaction (Dunlap, 1980).  Task Variation has been empirically validated to show improve correct responding and increase positive affect during teaching interaction (Koegel et. al 1986).

Varying maintenance and acquisition trail is an essential tool that builds a wide behavioral repertoire and enhances learner engagement and motivation. The learner experiences a high rate of success due to successful responding on maintenance trails which also increases the rate of success for acquisition trials. Literature has described this concept as Behavior Momentum (Singer et.al 1987).  With this strategy, the learner is presented with at least 3 short commands that are easy and mastered in the learner’s repertoire followed by a difficult request. By preceding with a task that has a high rate of success the learner builds momentum for the difficult task through repeated reinforcement. This also leads to decreased in escape-maintained behavior and an increase in positive responsiveness for difficult tasks (Singer et.al 1987).

A study done by Dunlap in 1984 evaluated and validated the role of antecedent variables that affect learning in context with which tasks are sequenced within an instructional session. The research was done in an alternating treatment design which evaluated the effect and rate of task acquisition under three experimental conditions in participants diagnosed with Autism. The three conditions alternated were a constant task condition in which only one acquisition task was presented per session, a varied-acquisition-task condition, in which 10 acquisition tasks were randomly interspersed throughout each session and a varied-with-maintenance-task condition, which randomly interspersed 5 acquisition tasks and 5 which had been previously acquired. The results showed significantly more efficient learning under the varied-maintenance condition, with no consistent differences separating the other two conditions. In addition, observers’ ratings of the children’s effect showed that the most positive judgments were produced by the varied-maintenance condition. The varied-acquisition condition was next while the constant task condition always produced the least favorable ratings.

Varying stimuli in learning aids in the generalization of the skill since the responses are not tied to specific stimuli. This also enhances learner’s motivation since varied tasks are presented as opposed to a single task being presented in a drill-practice format. A study done by Dunlap and Koegel in 1980 evaluated the differential effectiveness of two methods of presenting discrimination task to children with autism. The study was conducted in a within-subject, multiple baselines across participants design in which varied tasks were alternated with constant tasks to evaluate a number of correct unprompted responses to questions. The study also evaluated participants enthusiasm, happiness and motivation to learn. In a constant task condition, the common method of presenting a single task throughout a session was used. In a varied task condition, the same task was interspersed with a variety of other tasks from learner’s education plan. Results showed declining trends incorrect responding during the constant task condition, with substantially improved and stable responding during the varied task conditions. In addition, naive observers judged the children to be more enthusiastic, interested, happier, and better behaved during the varied task sessions. These results suggest that “boredom” may be a particularly important variable to control in the treatment of autistic children, and that particular care may be necessary when defining criteria for task acquisition.

Rewarding Attempts

Reinforcing attempts have also been suggested to be an important motivational variable in Pivotal Response Treatment (Koegel et.al 1988). Research has established that reinforcing attempts for successful task completion exposes the learner with response-reinforcer contingency thus eliminating a state of learned helplessness (Koegel et.al 1979). The phenomena of learned helplessness was studied by Seligman, (1972) who suggested that learned helplessness results when there is a delay between the reinforcer and response or when the learner gets excessive help without making response attempts. Since children diagnosed with autism struggle with low motivation the learned helplessness also contributes to extinguishing the initiation of later response since the previous response was either not reinforced promptly or the learner was not given a chance to respond. The concept of learned helplessness is very important particularly for early intervention since typically developing children show an understanding of response-reinforcer contingency as early as 9 months.

Early intervention gives children exposure to the response-reinforcer contingency by precisely reinforcing attempts to appropriate behavior and extinguishing maladaptive behavior associated with learned helplessness. (Seligman et. al 1968) For example, a nonverbal 18-month old who is starting to make verbal communicative intent reaches for a book and says, “Ooo!”. Although this is not the targeted response, such as, “book”, the adult immediately reinforces the attempt by saying “book!” while handing the book to the toddler. This naturally reinforces the attempted vocalization and re-models the target response by using loose shape criterion. Reinforcing attempts is very effective when child’s goal-directed responses ( “oo” to request book)that are as good or better than the previous ones are reinforced by an adult which results in increase responsiveness, initiation and motivation during learning interaction.

In a seminal study about motivation by Koegel and Egal (1979) demonstrated that when children with autism repeatedly responded incorrectly to tasks their enthusiasm responsivity decreased to extremely low levels. The study was conducted in a reversal design on three participants diagnosed with Autism to investigate the influence of correct vs incorrect task completion on children’s motivation. The researchers found out that when children worked on tasks that were typically incorrect, their motivation for those tasks decreased to extremely low levels. However, designing treatment procedures to prompt the children to keep responding until they completed the tasks correctly served to increase their motivation to respond to those tasks. The research was concluded by stating that when children do not contact reinforcement for attempted response their motivation to learn decreases. The study also concluded that delayed reinforcement may result in coincidental reinforcement for perseverance.

A ground-breaking study was done by the advocators of Pivotal Response Treatment that validated the motivational variable of reinforcing attempts was done by Koegel, O’ Dell, and Dunlap in 1988. The researchers measured improvement in speech production and also affect of the participants by comparing them under two different reinforcement conditions; one in which successive motor approximations of speech sounds were reinforced; and a “motivation” condition in which attempts to produce speech sounds were reinforced, without any motor shaping of speech. The results, replicated within a repeated reversal design, indicated that considerably more rapid and consistent progress occurred when the children were reinforced within the framework of a speech attempts contingently rather than solely on the basis of their correct speech production. The result also showed considerable improvement in children’s’effect in terms of interest, enthusiasm, happiness, and general behavior during the condition when speech attempt was reinforced.

Use of Direct Natural Reinforcers

A major motivational variable that encompasses Pivotal Response Treatment and impacts the response-reinforcer relationship is the use of direct- natural reinforcers in learning interactions. Natural reinforcers are directly and functionally related to the task (i.e. one that are within the chain of behaviors required to produce the reinforcer) so that when children emit the target response, they naturally obtain the reward.  As stated by Skinner (1954) rewards that are directly related to the behavior that is taught, produce faster and more generalized learning. Researchers of PRT also concluded through empirical studies that learners with Autism are much likely to acquire skills rapidly when reinforcers are directly related to the given task (Koegel et. al 1980). For example, the therapist could use a clear lid box that has learner’s favorite toy or edible to work on verbal request goal. When the learner uses gestures, sign or words (depending on the target), to request help to open, the therapist would give access to the reinforcer inside the box thus reinforcing the child with a natural reinforcer. Similarly, another example could be while working on social engagement with a toddler, the therapist would stop in between a sensory social routine to motivate the learner to give eye contact or use gestures to request for more. Kazdin (1977) speculated that using a natural, direct reinforcer is an effective strategy to build a strong response-reinforcer relationship because the response occurs in very close temporal and physical proximity to the reinforcer. When using an arbitrary reinforcer, the child gets a reinforcer contingently, but the reward is not functionally related to the response. For example, the therapist gives the learner an M&M along with verbal praise when the learner emits a correct response.

Koegel and Willian (1980) demonstrated a simple example of a direct reinforcer relationship for children with Autism in a study that experimented the percentage of correct responses. The study was done in a multiple baselines across 3 participants which evaluated 2 different response-reinforcer relationships; first, target behavior was part of the response chain required to obtain reinforcer (e.g., opening the lid of a container to obtain a food reward inside the container), and second, where the target behavior was an indirect part of the chain leading to the reinforcer (e.g., the therapist handing the child a food reward after the child had opened the lid of an empty container). The results showed rapid acquisition only when the target behavior was a direct part of the chain leading to the reinforcer.

Another study that looked at the functional relationship of the reinforcer with the response was done by Willian, Koegel, and Egel in 1981 by comparing 2 conditions of delivery of reinforcement in multiple baselines across 3 participants. The study looked at the rate of children with autism learned by targeting a percentage of correct unprompted responses. The researchers manipulating two conditions while holding target behaviors constant. In the first condition the reinforcer was delivered as a direct chain of the response (reinforcer in hand if target behavior involved hand movement) and for the second condition the reinforcer was delivered arbitrarily (reinforcer in hand if target behavior involved mouth movement).  The results showed that arranging functional response-reinforcer relationships produced immediate improvement in the children’s learning and resulted in the rapid acquisition of criterion level responding. The study also showed that high levels of correct responding initially produced by functional response-reinforcer relationships were continued even when previously ineffective arbitrary response-reinforcer conditions were reinstated.

Social Engagement, eye contact, low social effect, and joint attention are very fundamental skill deficits in young children with autism. A study by Koegel Vernon and Koegel looked at improving social initiations of young children with autism by embedding reinforcers in social interactions. Using an ABAB research design with three children with autism, this study assessed whether embedding social interactions into reinforcers, delivered during language intervention, would lead to increased levels of child-initiated social behaviors. This condition was compared with a language intervention condition that did not embed social interactions into the reinforcers. Results indicated that embedding social interactions into the reinforcers resulted in increases in child-initiated social engagement during communication, improved nonverbal dyadic orienting, and improvements in general child effect.

Parent Education

Families are an integral focus of the application process of Pivotal Response Treatment. In the PRT model, parents are viewed as a critical agent of delivery of their child’s behavioral intervention. Research has established that parent education is an important element of a child’s developmental goals (Baker, 1989). Earlier work in the parent education field was done by Wolf, Risley, and Mees (1964) who began working with parents of children in the residential settings aiming to generalize successful training programs at home. A follow-up study was done by Lovaas, Koegel, Simmons, and Long (1973) concluded that children whose parents were trained continued to show treatment gains versus those children who were discharged to institutions who did not employ behavior programs. Subsequently, parents were viewed as “co-therapists”; primary therapy agents in child’s development therapy program (Shopler et al 1971).

For parent education to work effectively, it is important that the service delivery is within the context of the ecocultural theory (Bernheimer et.al. 1990), which means that the intervention is planned around family’s culture, value system, and daily routine. Since the PRT model is based on naturalistic teaching (Hart et. al 1975), parents are trained in the natural setting and within family routine such that they can implement the procedures in their everyday routine and find teaching opportunities during natural parent-child interactions. In addition to the child’s developmental gains, research has also shown collateral effects on parents as a result of positive family interactions (Koegel et.al 1996) and the positive effect of parents towards children (Schreibman et.al 1991).

Training parents to conduct child’s training programs at home, in a natural environment, throughout a child’s waking hours relates from “transactional model of development” (Sameroff, 1975). According to this model, a child’s development is understood as a transaction process between a child’s behavior, the caregiver response to the behavior and the environmental context where the interplay occurs. This transaction influences significant treatment gains in the child ‘s social, communication and language development (Wetherby et. al 2000). The PRT model embraces this strategy by addressing the child’s development in natural context; parents are trained to implement the motivational package thereby moving the child toward a more typical developmental trajectory.

Among numerous empirical studies that validated the efficacy of parent’s education in the context of the PRT, the model is a study done by Koegel, Bimbela, and Schreibman (1996). The researchers assessed the collateral effects of two very different parent training models during unstructured dinnertime interactions in the family setting. One program focused on teaching individual target behaviors (ITB) to one group of family, and the other focused on applying the PRT model which comprised of the motivational package. Pretraining and post-parent-training videotapes of dinnertime interactions were scored in a random order across four interactional scales (level of happiness, interest, stress, and style of communication). Results showed no significant influence on the interactions from pretraining to post-training in the families who received ITB training. However, the PRT parent training paradigm resulted in the families showing positive interactions on all four scales, with the parent-child interactions rated as happier, the parents more interested in the interaction, the interaction less stressful, and the communication style as more positive. Another study (Schreibman et. al 1991) that focused on parent affect while conducting PRT model versus the Discrete Trail model also concluded the parents implementing the pivotal response training procedure were rated as exhibiting significantly more positive effect than those parents implementing the discrete-trial procedure

Parent training in the PRT model is ideally suggested to be conducted in a 25-hour program (Kasari, 2002), which could sometimes be challenging in regard to a long waiting list and timely access to intervention. A study was done by Coolican, Smith, and Bryson (2010) suggested that less intensive parent training program may also be effective. The study was conducted to evaluate the efficacy of brief parent training program on parents of preschool children with autism who were awaiting, or unable to access more comprehensive treatment. The research was conducted in nonconcurrent multiple baselines across participants design, in which parents were seen individually for three 2-hour training sessions on PRT. Child and parent outcomes were assessed before, immediately after, and 2 to 4 months following training using standardized tests, questionnaires and behavior coded directly from video recordings. The results were spectacular; children’s communication skills, namely functional utterances increased following training. Parents’ fidelity in implementing PRT techniques also improved after training, and generally, these changes were maintained at follow-up. A moderate to a strong relationship was found between parents’ increased ability to implement PRT techniques and improvement in the children’s communication skills. This study validated that brief parent training in PRT provides an immediate, cost-effective intervention that could be adopted widely.

Since the Pivotal Response Training model has been widely applied in the early intervention setting, one study that targeted parent training to infant at-risk is done by Steiner, Gengoux, Klin, and Chawarska (2013). The research applied a developmental adaptation of PRT through a brief parent training model with three infants at-risk for autism. Utilizing multiple baseline designs, the data suggest that the introduction of PRT resulted in increases in the infants’ frequency of functional communication and parents’ fidelity of implementation of PRT procedures. This study validates the support for the feasibility and utility of PRT for very young children at-risk for autism. Another study was done by Laski, Charlop, and Schreibman (1988) on parents of four nonverbal and four echolalic autistic children who were trained to increase their children’s speech by using the PRT model conducted in a play environment with a variety of toys. Parents were initially trained to use PRT procedures in a clinic setting, with subsequent parent-child speech sessions occurring at home. The results indicated that following training, parents increased the frequency with which they required their children to speak (i.e., modeled words and phrases, prompted answers to questions). Correspondingly, all children increased the frequency of their verbalizations in three non-training settings. Thus, the PRT was validated again to be an efficacious program for parents to learn and use in the home to increase their children’s speech.

Professional and Ethical Compliance Code and Pivotal Response Treatment

The Professional and Ethical Compliance Code for Behavior Analysts established by the Behavior Analyst Certification Board sets forth the principles for ethical conduct for all behavior analysts and behavior technicians. These codes provide guidelines about the kinds of actions by the professionals and interactions between professionals and clients that are ethical and lays out clear guidelines for those principles that are not ethical as suggested by the BACB. Ethical considerations are integral to professionals who provide early intervention services as they are faced with difficult choices regarding service and support for children and families. Van Houten et.al in their seminal article, “Right to Effective Treatment” advocate for rights of individuals who receive behavior analytic services under which behavior change agents have a responsibility to provide the most effective treatment by a competent behavior analyst. They also have the right to receive services in a therapeutic environment with programs that teach functional skills, behavioral assessment and ongoing evaluation, and services that have a prevailing goal of personal welfare. This chapter will discuss how Pivotal Response Treatment adheres in regard to the PECC and the ethical dilemmas that encompass challenges when making the right choice in service delivery for young children with disabilities.

One of the hallmark characteristics of Applied Behavior Analysis is its reliance on scientifically validated treatments. Behavior therapists who apply Pivotal Response Treatment must maintain their adherence to the values of scientifically validated treatments. The Guidelines for Responsible Conduct developed by the Behavior Analyst Certification Board contain several relevant directives; Section 1.01 (Reliance on Scientific Knowledge) from Responsible Conduct of a Behavior Analyst states that “behavior analysts rely on scientifically and professionally derived knowledge when making scientific or professional judgments in human service provision, or when engaging in scholarly or professional endeavors.” PRT embodies this code by applying the scientific principles of Applied Behavior Analysis (Koegel et.al. 1987). The foundation of PRT is based on operant teaching principles and four-term contingency (Michael, 1993) to motivate the learner. PRT also aligns with the 7 dimensions of ABA as suggested by Bear, Wolf and Risley (1968) in their seminal paper, “Some Current Dimensions of Behavior Analysis”. Thus, the foundation of PRT principles are conceptually systematic and align with PECC code 4.02 which states that “Behavior Analyst design behavior change programs that are conceptually systematic”.

Another important area that Behavior analysts have an ethical obligation is their responsibility to clients which is laid out in detail in code 2.0. Behavior analysts value the provision of effective services from the onset; from accepting clients to responsibility towards all the parties involved in the behavior change process, behavior analyst utilizes procedures that have been validated to be effective having both long-term and short-term benefit to the client and society. PRT model proposes for an effective treatment that is coordinated by all relevant stakeholders (Carr et.al 2002) so that a consistent intervention is implemented across people settings and environments. Therefore, pivotal response treatment model not only aligns with the PECC code for treatment efficacy but also meets the rights of individuals as advocated by Van Houten et.al (1988).

Behavior analysts struggle to work collaboratively with consumers and other professionals while maintaining their adherence to the values of scientifically validated treatment and implementation of an effective intervention. Code 2.03 (consultation) states that behavior analysts have a responsibility to collaborate with other professionals on the team keeping client best interest as a priority. Since PRT is applied in the naturalistic environment, the therapists have to work with other team members such as occupational therapist and speech therapist with a collaborative goal. Such dilution of services often leads to reduced effectiveness especially when components of PRT are not applied and there is less time allocated to work towards the pivotal areas of development. In addition, there may be inconsistencies between approaches or interactions between treatments with differing philosophies and methods. It is often difficult for behavior analysts to discern how they should conduct themselves in these contexts.  One good resource to analyze the efficacy of treatment by other professionals is given by Broadhead (2015); he suggests a decision-making model that could help BCBAs to assess no behavioral treatments while maintaining an ethical balance between professional relationships and well-being of the client.

Since parent education is an integral part of Pivotal Response Treatment, one code of ethics that PRT therapists often seem to encounter is third-party involvement in services (Code 2.04).  To be an effective treatment model, PRT is suggested to be carried at home as a lifestyle change (Sameroff and Chandler, 1975) which makes parent training a fundamental component of the treatment. This component brings a challenge for the behavior therapists who are training parents to generalize the strategies at home regarding treatment fidelity. Stocco and Thompson (2015) reviewed the evidence supporting child behavior as controlling antecedents and consequences for parent behavior. PRT therapists often encounter a lack of treatment follow up at home due to various reasons reported by parents such as the child being sick or schedule changes. Under such conditions behavior analyst also find themselves in a situation where they have to analyze violating code 2.09 (b) which states that behavior analysts have a responsibility to provide and oversight services that are required to meet the goal of the behavior change program.

Another challenge that is unique to early intervention is assent; learners agreement to participate in learning. Kohl (1991) stated that for effective learning to take place it is very important for students to be motivated to participate in learning and it is imperative that teachers respect this right to either refuse or agree to participate before learning can take place. The BACB addresses this by having behavior analysts abide by code 4.02 which states that behavior analysts involve the client in the planning of and consent for behavior change programs. Code 4.04 states about having client’s consent before making changes to program and Code 4.05 about explaining the objectives of the program and environmental conditions that interfere with implementation (4.07). Since early intervention deals with young learners who lack the appropriate skills to express their consent and advocate for their consent withdrawal, it makes it harder for educators to create environments that result in consented learning. Code 9.03 states clearly that behavior analyst has a responsibility to acquire informed consent from clients in any way that helps the clients to understand their right to participate and withdraw from treatment. Fabrizio (2012) reported that assent withdrawal can be demonstrated by low task participation, performance or avoidance. The learner begins to exhibit behaviors such as avoiding the educators, avoiding tasks by exhibiting aberrant behaviors, participating far below their ability, leaving or trying to leave tasks and refusing to follow instructions. Since the foundation of PRT is based on a motivational package (Koegel, O Dell and Koegel, 1987) that comprises of specific variables (child choice, use of natural reinforcer, reinforcing attempts and task variation) that have been empirically validated to contribute to reduction in disruptive behaviors and overall child’s positive behavior and enthusiasm to learn (Vismara and Lyons, 2007). Thus, the behavior change program in PRT is designed around learners’ consent and motivation to learn.

Since PRT basis its foundation on the motivational variables, it embodies the PECC codes that pertain to using positive reinforcement procedures (4.08), in a natural environment (4.09), using natural reinforcers (4.10). These codes restrict behavior analysts to design behavior change programs that recommend reinforcement rather than punishment in the least restrictive environment, avoiding harmful reinforcers. This, however, comes as a challenge to behavior therapists who apply PRT strategies. For one, there are skills that may be hard to teach using a child-directed approach for example skills that the child may need to learn but does not find particularly motivating. This puts the behavior analyst in dilemma to use reinforcers that are contrived but must be balanced such that they are not harmful to the learner. Using natural reinforcers also come with a challenge of the learner being satiated especially edibles. Secondly, some children do not do well in an unstructured setting and require a more structured format for learning, such as Discrete Trial Training and that families going through difficult times or with high levels of stress may have more trouble with PRT than others (McClelland, 2016).

Limitations of Pivotal Response Treatment:

Since its conceptualization, PRT has received much empirical support for promoting therapeutic gains in functional, social and communication skills in individuals with ASD. Although the theoretical and empirical support for PRT as an effective strategy is documented, there are limitations to the extent to which the outcomes from this research can be generalized. For instance, until recently most research had come from the same region of the country, either in connection with the research teams at the University of California in San Diego or the University of California in Santa Barbara. This makes it imperative for third-party evaluators to analyze PRT by itself and compared other evidence-based treatments on research guidelines for ASD.

The critics of PRT base their argument against its effectiveness on the grounds of treatment integrity which is an important indicator of intervention quality and student outcomes. A study done by Stahmer et. al (2014) examined 3 different evidence-based practices (Pivotal Response Treatment (PRT), Discrete Trial Training (DTT) and Functional Routines (FR)) for ASD in terms of treatment fidelity.  The results suggested therapists had in general, significantly greater difficulty implementing PRT with fidelity than either DTT or FR. Both average and best fidelity scores across teachers are lower for PRT than either DTT or FR. The researchers suggest that teachers might have difficulty with specific components of PRT that are not well-suited to the classroom environment. Other research also validates this finding indicating that PRT can be difficult to implement as the sole program in a classroom setting (Suhrheinrich et al., 2013) and that families going through difficult times or with high levels of stress may have more trouble with PRT than others. Recent data indicate that teachers may consistently leave out some components of PRT, which would reduce overall implementation fidelity of the comprehensive model (Suhrheinrich et al., 2013).

A recent publication, Bozkus-Genc and Yucesoy-Ozcan. (2016), conducted a meta-analysis of PRT studies and concluded only half of the studies looked at PRT’s ability to generalize to other settings and less than half of the studies measured treatment integrity, maintenance, and social validity. Another study done by Cadogan & McCrimmon (2015) evaluated 17 PRT research studies to standards of ASD research quality and found substantial limitations in adherence to treatment fidelity standards; the research concluded distinct patterns of variation regarding adherence to treatment fidelity. Five studies made no reference to treatment fidelity measures, two studies followed the recommended treatment fidelity standard by requiring the therapist to implement strategies correctly, 80% of the time prior to entering the treatment stage.

PRT has also been criticized in terms of being ineffective for children who do not do well in such an unstructured setting and require a more structured format for learning, such as DTT. Critics of PRT also advocate that some skills are hard to teach using such a child-directed approach including skills that the child may need to learn but does not find particularly appealing (Downs, Conley-Downs, Fossum, and Rau, 2008).  Peggy Hammond a PRT certified, Licensed Behavior Analyst, expressed her views about PRT as an effective strategy for early intervention. However, she expressed the challenges that come with the application of PRT in terms of training parents and therapist to implement intervention with fidelity. She also expressed the limitation of PRT as a “one size fits all approach” and not able to provide individualized treatment plans for children with Autism.  Sherer and Schreibman (2005) identified participant characteristics associated with different outcomes for PRT intervention.  They identified distinct behavioral profiles to identify 6 children, (3 predicted responders and 3 predicted non-responders) who received PRT. Children with pretreatment responder profiles evidenced positive changes on a range of outcome variables as compared to children with pretreatment non-responder profiles who did not exhibit improvements. The results of this study validate the need for the development of individualized treatment protocols for children with autism.

Future Directions:

Pivotal Response Treatment has proved itself to be an effective intervention for children diagnosed with Autism. However, like other behavioral interventions, research has documented variable outcomes for children receiving PRT (Olley, Robbins, and Morelli-Robbins, 1993). Therefore, it is important that future implications emphasize predicting eventual treatment outcomes from children’s developmental trajectories from the start of the intervention. Some work in this area has been established by Koegel, Koegel, Shoshan, and McNerney (1999), who demonstrated that child’s initiation at program entry predicted high favorable treatment outcome. Another important study was done by Sherer and Schreibman (2005) that evaluated responder/non-responder profiles of children receiving PRT in terms of social behaviors and play skills. The study resulted in identifying the children as “responders” to PRT who had higher toy contact, social skills and play skills from the start of the intervention.

Recent advancement in the field of science has integrated neuroimaging techniques and behavioral science to help identify objective biomarkers of treatment (Lie and Ventola, 2017). The authors in their review of current perspectives on Pivotal Response Treatment established the need for tracking brain activities of children receiving PRT. This would facilitate future clinicians and therapists to compare the similar profile of behavioral changes observed over PRT and identify who will benefit from the intervention thus resulting in individualized interventions and maximum treatment gains for each learner. A recent, pilot study published by Hegarty et. al (2019) investigated language regions in the brain of children who received PRT to target language deficits. Results suggested similarities at baseline in regions of the brains of children who responded to the language therapy using Pivotal Response Intervention. Although preliminary, using neuroimaging to help identify which children are most likely to benefit from specific language treatments would facilitate precision medicine for children with ASD.

Using a motivational package that targets pivotal skills has been very successful especially in the area of acquiring verbal communication, however, there is a subpopulation of nonverbal children who have not yet responded to PRT successfully (Koegel, Koegel, and Brookman, 2003). With a growing number of non-verbal children with Autism acquiring speech effectively when being exposed to evidence-based treatments, it is critical to further assess variables that would also be effective for children who are currently considered to be non-responders (Koegel and Koegel, 2006). Future implications of PRT research should examine motivational strategies that would also be effective for non-verbal children (Koegel and Koegel, 2006).

Another implication of PRT arises from the need to disseminate comprehensive service delivery models such that Pivotal Response Treatment can be implemented on a larger scale with fidelity. One mechanism could be training teachers and paraprofessionals to integrate PRT strategies in the preschool curriculum to effect a large number of children from a young age. Two studies have outlined procedures for training parent implementers to provide PRT for large-scale community-based training; Baker-Ericzen, Stahmer and Burns, 2007 and Bryson et.al 2007). Baker and colleagues (2007) implemented training to 158 parents of children with ASD for a total of 12 hours over the course of 12 weeks. Although child improvement gains were noted by comparing pre and post measures on the Vineland Adaptive Behavior Scales, the fidelity of implementation by parents was not monitored. The authors stressed the importance of greater adherence to treatment fidelity in future research.

Bryson et.al (2007) trained teams of parents and intervention providers to implement PRT as part of a province-wide dissemination project in Nova Scotia, Canada. The researchers Bryson et. outlined procedures that were employed in a train-the-trainer model to build capacity for early childhood services through parents and educators in Nova Scotia. This has been the only study to date to include practitioners as agents of change. Initially, in-vivo training was provided to train the trainers using Behavior Skills Training (Parsons, Rollyson, and Reid, 2012). Once trained, the new trainers provided instruction to parents and educators in a group format utilizing the skills they had been taught. Preliminary data indicates the promising potential for implementing a train-the-trainer model to build the capacity of services for children with ASD.

Finally, another way for increasing PRT implementation is for more research to be conducted in schools and particularly in inclusive general education classrooms. While early intervention is targeted mostly in inclusive school settings as much as possible, a few studies have evaluated PRT interventions either in the classroom (Koegel, Koegel, Frea, Green-Hopkins, 2003) or with academic tasks (Koegel, Singh, & Koegel, 2010); most of the research supporting PRT has been conducted in home, clinical, and community settings. Since PRT is applied in natural environments, it makes imperative to conduct future research on how to best to train teachers to correctly implement PRT in inclusive, general education classrooms.

Conclusion

Literature supports early intervention is crucial to the development and successful prognosis of young children diagnosed with Autism (Lovaas, 1987; Elder, Kreider, Brasher, and Ansell, 2017). PRT is an empirically supported intervention based on principles of Applied Behavior Analysis that focuses on incorporating motivational variables to target pivotal areas of learning. These variables include child choice (Koegel, Dyer, & Bell, 1987), task variation (Dunlap, 1984), reinforcing attempts (Koegel, O’Dell, & Dunlap, 1988), and using direct natural consequences (Koegel & Williams, 1980; Williams, Koegel, & Egel 1981). As a package, these variables have been shown to be extremely effective, when compared to structured ABA approaches. Overall, PRT is a viable and empirically supported intervention for children with ASD. It embodies a naturalistic teaching approach and promotes parents as active agents of change in children’s lives. PRT strategies have been exceptionally validated to be successful in enriching social/communication abilities across all ages in children diagnosed with ASD. Although research has supported the use of PRT as an effective form of early intervention, the quality of PRT research has yet to be addressed especially in the area of fidelity of implementation.; there is a paucity of research available that supports fidelity of PRT to be maintained and generalized after training. A future implication of PRT research needs to be done on determining the profiles of learners who will benefit from PRT intervention as well as towards fidelity of implementation.

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