Social Stories

Social Stories are a great way to target pragmatic/social difficulties you are having with a client or a child of your own.

One kid I worked with in my internship in the schools was TERRIFIED of pigeons. Like, would not walk within 100 ft. of them, and instead had to walk around the entire perimeter of the school to avoid them, terrified.

So, we wrote and "produced" :) a social story about Pigeons.

Here are a couple pictures of the finished product:

(Full text reads: Pigeons are friendly birds that like to eat worms and fly in the air. There are a lot of pigeons at X Elementary that I see when I walk around the school. They especially like to hang out around the cafeteria. I may not like pigeons, but I can walk by them without covering my ears. I can pass them calmly because I know they can't hurt me. I am brave around pigeons.)



On other pages we included pictures of the little boy so that he knew the book was about him.

After a couple days of reading it each session before working on other goals, he started to warm up to the birds. We no longer had to walk around the entire school and he even thought they were kinda cool.

We then had him take his own pictures of the pigeons and we added a page of his photography to the book:
He loved being involved in the process, and he got pretty dang close to those birds when trying to get a good pic. By the end of the semester, even though he wasn't wanting one for a pet, he definitely was more tolerant and less scared of them.

I also made a social story for a client who was having a lot of difficulty losing. Another story I made for my two year old son who was having a hard time sharing his toys with friends who came to our house. Both social stories were effective and helped to decrease undesired behaviors.

So try em out. I've been encouraged by their effectiveness.

Alphabet Knowledge

I discovered Lakeshore this summer on a break I had between clients. It was great for me, but not so great for our wallet (especially when I was already paying ASU for the clinical rotation, ha ha). Basically, Lakeshore is a teachers/speech pathologists/educators/moms dream store for teaching materials. It's the best.

My first visit I wanted to buy everything on the shelf. But, I controlled myself and only bought these two products:

These are tactile letters, and I only bought the uppercase ones (for now). The letters are textured with a rough, sand-paper feel. In school we learn that kids learn in many different ways. Generally, when you can present information to them in multiple modalities (visually, auditorily, tactily), they learn it easier/better/faster. That's why I love these letters. Kids can see and feel them simultaneously, and can really "get to know" the letters if you will.

My son and I played with them for hours yesterday and he loved them! He cried when he couldn't take them with him for his nap.


I also bought these lowercase letter cubes (though I bought a pack of 6 that are all over double the size of the ones pictured). These letter cubes are great because you can really play and have fun with the letters. My son and I would roll them back and forth to each other and then we'd hurry and try to find a specified letter on the cube. Or we just took turns rolling the dice and trying to get a specified letter. We also played a racing game where we lined 3 cubes up on the couch on one side of the room, went to the other side of the room, and then raced to get a specific letter. My son loved beating me and getting to the appropriate letter first.

Making learning fun will engage your child and help them to enjoy working with the letters at a young age.

Neural Plasticity in Cochlear Implants

The ability to hear consists of a complex sequence of physiological events. As sounds from the environment enter the ear, they travel through the ear canal and hit against the tympanic membrane. This pressure against the tympanic membrane then causes the oscicles (bones) of the middle ear to move. The stapes, the last in the sequence of middle ear bones, pushes against a fluid-filled window in the cochlea, which then vibrates the fluid inside. This vibration of fluid moves the structures in the cochlea, which stimulates the hair cells located within. The stimulation of hair cells sends an impulse to the auditory nerve. From the cochlea, the auditory nerve travels through the brainstem and up to Heschl’s gyrus, the primary auditory cortex, where sound is processed and analyzed. The impulse then travels further to Wernicke’s area where the signals are “interpreted into language-specific meaningful messages for the comprehension of spoken language” (Bhatnagar, 2008).

Damage at any point in this sequence can result in hearing loss. There are three main types of hearing loss: conductive, sensorineural, and mixed (which is a mixture of conductive and sensironeural). Conductive hearing loss is caused by damage to the outer or middle ear and affects sound transmission to the cochlea. A common form of conductive hearing loss in children is otitis media, or a middle ear infection, which occurs when fluid fills the middle ear and decreases the movement ability of the tympanic membrane and middle ear oscicles. In adults the most common form of conductive hearing loss is otosclerosis in which a bone growth restricts the stapes from moving. Conductive hearing loss is generally less severe than other types of hearing loss and is “characterized by fluctuating hearing loss, good word-speech recognition ability at high intensities, softly spoken speech, impaired auditory reflex, and an air bone gap” (Bhatnagar, 2008).

Sensorineural hearing loss is caused by damage to the hair cells in the cochlea or damage to the auditory nerve. Damage here can result from noise exposure, toxicity, degeneration, tumors, disease, etc. Sensorinerual hearing loss severity “can range from moderate to complete in the affected ear” and is characterized by “difficulty in understanding speech, particularly in noise and tinnitus” (Bhatnagar, 2008).

Some hearing can be restored in certain cases of sensorineural hearing loss through the use of a cochlear implant. This device contains a microprocessor, which separates the incoming sound into frequency, and an electrode, placed in the cochlea, which electrically stimulates the auditory nerve. Although some hearing is restored, the process of stimulation differs greatly from normal hearing physiology. In a cochlear implant, the dynamic range is “much less than that of the normal activation of auditory nerve fibers through excitation of inner hair cells”. In addition, the “randomness in the temporal firing is much less” and the “spread of excitation is much larger” in cochlear implants (Kral, 2006). Therefore, all people with cochlear implants must “learn to interpret this new input” (Kral, 2006).

Interpreting the input of a cochlear implant is even more complicated in people who are congenitally deaf and who have never heard. In these cases, the brain “has never learned to process the auditory information” and has reorganized as a result. In 1977, Rebillard found evidence to suggest a “possible reutilization of the cortical auditory areas deafferented from its primary modality”. More recent research has supported this theory, saying that “prelingual deafness results in partial reorganization of [the] cerebral cortex” (Wolff, 1990). Because of this reorganization, many support the theory of an early, critical period for the implantation of a cochlear implant.

Additional support for this critical period involves the early maturation of the auditory system and the evidence of synaptic deletion. Development of the cochlea is morphofunctionally complete at 24 weeks gestation and brainstem evoked responses have been “found in premature children” born at 28-29 weeks (Manrique, 1999). Additional development continues throughout the first 5 years of life as myelination occurs, and the auditory system matures. “The progressive changes in the auditory pathways and centers are to occur during the first 10 years of life, being especially dynamic in the first 5 years. In this particular period the human being has the most neuronal plasticity, or in other words the CNS has the greater ability to change the developmental pattern according to environmental influences” (Manrique, 1999).

If not stimulated, however, as in cases of congenital hearing loss, synaptic deletion can occur. Multiple studies have shown that removal of the cochlea results in loss of neural and cortical tissue associated with audition. Tierney, Russel, and Moore studied this effect in 1997 by removing the left cochlea in gerbils. They found statistically significant “whole nucleus volume reduction”, and a reduction in the “mean number of neurons” as a result. They concluded that there was “massive loss in CN [Cochlear Nucleus] neurons following deafferentation” (Tierney, 1997). Additional studies “observed a 14%-34% size decrease in neuronal somas” (Manrique, 1999) and others found an even greater “58% size decrease in neuronal somas within the CN” (Hashisaki, 1989) when the cochlea was removed. These studies support the “use it or loose it” theory that suggests that cortical and subcortical tissue not used during the critical years of development will die or be reassigned to other processes.

So, if deafferentation and reorganization occur as a result of hearing loss, can cochlear implants re-teach the brain to use the changed cortical tissue or prevent the changes from occurring all together? Born and Rubel (1988) found that “the effects of denervating muscles can be largely reversed by direct electrical stimulation”. Leak (1999) also found this to be true within the spiral ganglion (SG) of kittens. Their research suggested “a 20% difference in density” in the SG cell somata between stimulated and non-stimulated ears, and showed cells “were significantly larger in the stimulated ears”. This indicates that if implanted early enough, synaptic deletion can be curbed and the brain can learn to process and use the incoming electrical-auditory stimuli.
Although the brain learns to use the stimuli, research continues to suggest that the brain reorganizes to accommodate for the changes in stimulation after implantation. One such study states that “postlingually deaf subjects learn the meaning of sounds after cochlear implantation by forming new associations between sound and their sources” (Giraud, 2001b). Giraud, Price, Graham, and Frackowiak (2001a) investigated this subject by looking at the involvement of the visual cortex in auditory language tasks after cochlear implantation. They used PET scans to examine the cortical activity of 12 subjects and found that all showed “significant activation of [the] visual cortex” (Giraud, 2001a). Specifically, the calcarine sulcus and lingual gyrus were active during these tasks. This activation was not present in the control group of normal hearing individuals.

Ponton and Eggermont found differences in auditory evoked potentials between people with cochlear implants and normal hearing individuals. Specifically, they found differences in P1 latencies, which measure the delay in synaptic propagation through the auditory pathway. They observed “prolonged P1 latencies compared to age-matched normal-hearing peers” and specifically found “a delayed maturation nearly equivalent to the period of deafness” (Ponton, 2001).

Sharma, Dorman, and Kral found similar differences in their 2005 study when they looked at the P1 latencies of early (before age 3.5) and late (after age 7) implanted, congenitally deaf children. They found that “both early- and late- implanted children showed a 35% decrease in P1 latencies in the initial month after implantation”, but after that they found “significantly different P1 latency” between early and late implanted groups (Sharma, 2005). In a study prior to that, Sharma, Dorman, and Sphar (2002) found that in children implanted at age “11 or older”, there was “very litte or no change in P1 latency after 1 to 2 years of electrical stimulation”. Children implanted by age 7 however, showed decreases in P1 latency “within a year of implantation”, and “children implanted before age 3.5” were found to have “very large decreases in latency within the first several months after the switch on” (Sharma, 2002).

These studies suggest that age of implantation significantly affects auditory pathway maturation and that, if implanted early, children can have latencies “within normal limits”(Sharma, 2005). They also support the theory of a ‘critical period’ in which the “auditory system appears maximally plastic” and therefore, the neural adaption to the cochlear implant is greatest.

Other reasons for early implantation involve the early development of language and the critical period associated with language acquisition. Studies have looked at the effect of early implantation on language and have shown a “rapid improvement in speech production and language acquisition after improved speech perception through a cochlear implant for these children implanted before 5 years of age” (Brackett, 1998). More specifically, children showed an increase in their receptive and expressive vocabulary and in sentence length and complexity in the first year after implantation, if implanted before 5 (Brackett, 1998).

Contrary studies have disputed the theory of a critical period, offering the opinion that all benefit from implantation and that it is “unlikely one critical period” exists (Harrison, 2005). They also discuss the biasness of the outcome measurement tool and that the measured behavioral outcome is “often the result of many mechanisms, each with a differing developmental dynamic” (Harrison, 2005). Even though these authors question a strict critical period, they admit there is an “age related plasticity effect”, and that “cochlear implant intervention at an early age in the congenitally deaf infant results in significantly better outcomes in speech understanding and language development” (Harrison, 2005).

In addition to age, Kral and Tellein (2006) suggest other factors that affect the outcome of the cochlear implant. “Peripheral Factors” include the “cochlear implant processor, the electrode type, its position and extent within the cochlea, pattern of degeneration in the auditory nerve” and the “status of myelination of the auditory nerve”. The other group of “Central Factors” includes the “status of the central auditory system (congenital, pre/postlingual deafness), it’s plasticity (age), and subjective cognitive factors that determine how effectively the subject adapts to the new type of sensory input.”

Although all of these factors are important, high neural plasticity may be the most pivotal of the central factors, as time of implantation can often be controlled. As suggested by many different studies, early cochlear implantation can decrease synaptic deletion, alter neural activity, and increase speech and language abilities. For all of these reasons, it is important children be implanted at an early age if the cochlear implant team, which includes the family, decides it is appropriate for the individual child.

References

Bhatnagar, S. C. (2008). Neuroscience: for the Study of Communicative Disorders (3rd ed.). Baltimore, MD: Lippincott Williams & Wilkins, a Wolters Kluwer business.

Born, D.E., & Rubel, E.W. (1988). Afferent Influences on Brain Stem Auditory Nuclei of the Chicken: Presynaptic Action Potentials Regulate Protein Synthesis in Nucleus Magnocellularis Neurons. The Journal of Neuroscience, 8, 901-919.

Brackett, D., & Zara, C. V. (1998). Communication Outcomes Related to Early Implantation. The American Journal of Otology, 19, 453-460.

Giraud, A., Price, C.J., Graham, J.M., & Frackowiak, R.S.J. (2001a). Functional Plasticity of Language-Related Brain Areas after Cochlear Implantation. Brain 2001, 124, 1307-1316.

Giraud, A., Price, C.J., Graham, J.M., Truy, E., & Frackowiak, R.S.J. (2001b). Cross-Modal Plasticity Underpins Language Recovery after Cochlear Implantation. Neuron, 30, 657-663.

Harrison, R.V., Gordon, K.A., & Mount, R.J. (2005). Is There a Critical Period for Cochlear Implantation in Congenitally Deaf Children? Analyses of Hearing and Speech Perception Performance after Implantation. Wiley Periodicals, Inc. Developmental Psychobiology, 46, 252-261.

Hashisaki, G.T., & Rubel, E.W. (1989) Effects of Unilateral Cochlea Removal on Anteroventral Cochlear Nucleus Neurons in Developing Gerbils. The Journal of Comparative Neurology, 283, 465-473.

Kral, A., Tillein, J. (2006). Brain Plasticity under Cochlear Implant Stimulation. Advances in Oto-Rhino-Laryngology, 64, 89-108.

Leake, P.A., Hradek, G.T., & Snyder, R.L. (1999). Chronic Electrical Stimulation by a Cochlear Implant Promotes Survival of Spiral Ganglion Neurons after Neonatal Deafness. The Journal of Comparative Neurology, 412, 543-562.

Manrique, M., Cervera-Paz, F.J., Huarte, A., Perez, N., Molina, M., & Garcıa-Tapia, R. (1999). Cerebral Auditory Plasticity and Cochlear Implants. International Journal of Pediatric Otorhinolaryngology, 49, 193-197.

Ponton, C.W., & Eggermont, J.J. (2001). Of Kittens and Kids: Altered Cortical Maturation following Profound Deafness and Cochlear Implant Use. Audiology & Neoro-Otology, 6, 363-380.

Rebillard, G., Carlier, E., Rebillard, M., & Pujol, R. (1977). Enhancement of Visual Responses on the Primary Auditory Cortex of the Cat after an Early Destruction of Cochlear Receptors. Brain Research, 129, 162-164.

Sharma, A., Dorman, M.F., & Kral, A. (2005). The Influence of a Sensitive Period on Central Auditory Development in Children with Unilateral and Bilateral Cochlear Implants. Hearing Research, 203, 134-143.

Sharma, A., Dorman, M.F., & Spahr, A.J. (2002). A Sensitive Period for the Development of the Central Auditory System in Children with Cochlear Implants: Implications for Age of Implantation. Ear and Hearing, 23, 532-539.

Tierney, T.S., Russell, F.A., & Moore, D.R. (1997). Susceptibility of Developing Cochlear Nucleus Neurons to Deafferentation-Induced Death Abruptly Ends Just Before the Onset of Hearing. The Journal of Comparative Neurology, 378, 295-306.

Wolff, A.B., & Thatcher, R.W., (1990). Cortical Reorganization in Deaf Children. Journal of Clinical and Experimental Neuropsychology, 12, 209-221.

Pivotal Resonse Treatment with children with Autism Spectrum Disorder

Pivotal Response Treatment (PRT) is an intervention model that incorporates a “developmental approach” and “applied behavior analysis (ABA) procedures” (Koegel & Koegel, 2006). It attempts to treat children in their natural home and school environments and provide them with “the social and educational proficiency to participate in enriched and meaningful lives in inclusive settings” (Koegel, Koegel, Harrower, & Carter, 1999). The PRT model is based on the theory that when targeting “pivotal” areas, success will generalize to other skills and other areas of the child’s life. Identified pivotal areas include: motivation, responsivity to multiple cues, self-management, self-initiations, and empathy (Koegel & Koegel, 2006). PRT includes several critical features that make it similar to, and distinguish it from, other interventions. These features include early intervention, hours and intensity of intervention, family involvement, natural environment and a specialized curriculum.

Early Intervention is critical to Pivotal Response Treatments for children with Autism. Not only has it been found to “maximize long-term benefits and prevent developmental problems for children with developmental disabilities”, but it has also been found to help children with Autism “make substantial developmental gains” (Koegel & Kegel, 2006). Because of this, early intervention is critical when providing PRT. An additional benefit of early intervention using PRT is that it helps to teach the response-reinforcer contingency, which is often critical for language development and is delayed in children with autism. The response-reinforcer contingency is the ability for children to learn that “their behavior [and communication] produces desired consequences from others in their environment” (Koegel & Koegel, 2006).
PRT, which incorporates ABA procedures, helps to teach this to children with Autism early on.

The PRT model strives for consistency and cohesion throughout all of the child’s environments, as it emphasizes the importance of spreading the service delivery “across all of the significant individuals and settings in the child’s life” (Koegel & Koegel, 2006). Thus, PRT is an hour intensive intervention. However, in an ideal model, parents, teachers, caregivers, and those who interact with the child are taught appropriate procedures for implementing PRT in natural environments. Therefore, it is a cost efficient model as the number of hours of “direct contact from a highly skilled specialist” is “relatively small” (Koegel et al., 1999).

In the PRT model, family involvement is key as it allows intervention to be continued at home. Lovaas, Koegel, Simmons, and Long (1973) studied the generalization of behavior therapy in children with autism and found that “groups whose parents were trained to carry out behavior therapy continued to improve”. Family education and training allows therapy to be conducted in the natural environment of the home by people that the child trusts and interacts with constantly.

As previously mentioned, providing therapy in the natural environment is vital in PRT. Research by Koegel, O’Dell and Koegel (1987) showed that providing treatment in naturalistic contexts helped to result in “broadly generalized treatment gains”. Naturalistic language approaches also allow for greater maintenance of gains made in intervention, and often provide more motivation for children.

The specialized curriculum in PRT refers to the specialized content and instruction that addresses “central deficits in autism through a focus on core areas of intervention in autism, particularly motivation” (Koegel & Koegel, 2006). Specifically, the PRT curriculum focuses on motivation while following and adhering to the general education curriculum. A great advantage to this model is that it allows for children with autism to be educated in the natural environment of the classroom with their typically developing peers. Accommodations in the classroom set the children up for success and make it possible for them to learn while the material and content remain constant. This helps to achieve the goals of PRT and the specialized curriculum, which are to “produce improvements that allow children with autism to move toward a typical developmental trajectory and to provide them with the opportunity to lead meaningful lives in natural, inclusive settings” (Koegel & Koegel, 2006).

One if the central aspects of the PRT specialized curriculum is its focus on motivation. Motivation is one of the “pivotal” areas of intervention and therefore, allows for generalization into other skills. In other words, when focusing on motivation, success is seen in multiple areas of treatment including “communication, self-help, academic, social, and recreational skills” (Koegel et al., 1999). Focusing on motivation not only facilitates improvements in children with autism, but Koegel & Koegel suggest that incorporating motivational activities into the classroom may benefit all students. The PRT motivational procedures include “using child choice, rewarding attempts, interspersing maintenance and acquisition tasks, and using natural and direct consequences” (Koegel & Koegel, 2006). All of these procedures can be included in the general education classroom, and can be used with all students or with individual students in need.

Another pivotal area targeted in PRT is responsivity to multiple cues. Children with autism have been found to have “stimulus overselectivity” which is “the child’s tendency to respond to an irrelevant component of a stimulus rather than to select the appropriate component” (Koegel & Koegel, 2006). Thus, targeting this area “may produce collateral changes in joint attention as children with autism learn to respond to multiple cues and, perhaps, to both the object and the communicative partner” (Koegel & Koegel, 2006).

PRT also targets the pivotal area of self-management. This is the ability for individuals to “discriminate and self initiate their own appropriate behavior, and then self-reinforce or self-recruit reinforcement for their appropriate behavior” (Koegel et al., 1999). This skill can benefit all areas of a person’s life and can generalize across many different environments.

Self- initiations also show broad benefit and generalization across multiple areas. Self-initiations consist of 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” (Koegel et al., 1999). Children with autism are typically lacking in this area. It is suggested that deficits here can lead to an individual being judged socially, whereas skills can result in self-learning and can have great affects across many different areas.

Empathy has also been suggested to be a “pivotal” area of intervention and is known to be of deficit in children with autism (Koegel & Koegel, 2006). However, more detailed description on the effect of intervention in this area was not found.

The PRT model is most effective with children who have good social relationships with more than one person, are demonstrating some joint attention skills, and have an interest in toy play. With these characteristics, a child may benefit more from the PRT model. Those providing the intervention include parents, teachers, caregivers, therapists, and all involved in the child’s life. Training is suggested for all who provide treatment to increase its fidelity. PRT training manuals can be ordered from UC Santa Barbara for $7.00.

Research on the effectiveness of PRT is showing positive results in all areas. Pierce and Schreibman (1997) studied the effects of PRT on social behavior when using peer trainers. They conducted a multiple baseline experiment with two children with autism, and ultimately concluded that “naturalistic interventions such as PRT are effective in producing positive changes in the social behavior of children with autism”.

Koegel, Bruinsma, and Koegel looked at the developmental trajectories of 5 children with autism before and after PRT early intervention. They found that following the intervention, the children made “rapid gains” and “considerable progress” as their range of words increased, spontaneous use of those words increased, and their “vocabulary was marked by both diversity and spontaneity” (Koegel & Koegel, 2006). In addition, “three of the five children’s developmental trajectories accelerated to near the level for typically developing children” (Koegel & Koegel, 2006).

A study by Vismara and Lyons (2007) looked at the affect of PRT on joint attention in 3 children with autism. Although all three children were showing zero joint attention initiations toward their caregivers at baseline, all increased “as a collateral gain when incorporating children’s PI (perseverative interest) stimuli as natural reinforcers within the motivational procedures of PRT” (Vismara & Lyons, 2007). In addition, “all children demonstrated improvements in qualitative measures of interaction with their caregivers in response to using perseverative and nonperseverative interests within the PRT methods” (Vismara & Lyons, 2007).

A larger scale study has begun to look at the implementation of PRT in a province-wide early intervention program for preschoolers with autism. In this study, intensive training was conducted to increase treatment fidelity. Specifically, one training was held for parents and interventionists, and one was held to train the trainers who would be teaching PRT to other trainees throughout the remainder of the province. Follow up measures are currently being scored and sample data is being collected. Data on one 5-year-old boy shows “a concomitant increase in child verbal utterances associated with the trainees’ improved fidelity of PRT implementation”. In addition, this data suggests a “dramatic increase in contingent reinforcement by trainees of the child’s verbal attempts” which is associated with an “equally dramatic increase in the child’s functional verbalizations” and “a corresponding increase in the child’s social engagement” (Bryson, Koegel, Koegel, Openden, Smith, & Nefdt, 2007). Additional results from this research will help to determine the effectiveness of PRT in large-scale dissemination and community implementation.

While the overwhelming majority of research suggests that PRT is an effective method of intervention, there are still some downsides. It is an hour intensive service delivery model and requires full participation of parents, teachers, and clinicians to be effective. In addition, PRT requires the child to have good social relationships with more than one person, demonstration of joint attention skills, and an interest in toy play. So, while it is a very effective method of intervention, it is not appropriate for all children with autism spectrum disorder.

Overall, PRT is proving to be an effective intervention model. Its “pivotal” areas of focus seem to have wide spread positive effects and help to increase the generalization of treatment gains. In addition, it allows children to receive intervention within naturalistic contexts and across all environments. PRT is seen as an empirically derived intervention and research continues to support its implementation.

References

Bryson, S. E., Koegel, L. K., Koegel, R. L., & Openden, E., Smith, I. M., Nefdt, N. (2007). Large Scale Dissemination and Community Implementation of Pivotal Response Treatment: Program Description and Preliminary Data. Research & Practice for Persons with Severe Disabilities, 32(2), 142-153.

Koegel, L. K., Koegel, R. L., Harrower, J. K., & Carter, C. M. (1999). Pivotal Response Intervention I: Overview of Approach. The Journal of the Association for Persons with Severe Handicaps, 24(3), 174-85.

Koegel, R. L., & Koegel, L. K. (2006). Pivotal Response Treatments for Autism: Communication, Social, & Academic Development. Baltimore, MD: Paul H. Brookes Publishing Co.

Koegel, R. L., O’Dell, M. C., & Koegel, L. K. (1987). A Natural Language Paradigm for Teaching Non-Verbal Autistic Children. Journal of Autism and Developmental Disorders, 17, 187-199.

Lovaas, O. I., Koegel, R., Simmons, J. Q., & Long, J. S. (1973). Some Generalization and Follow-Up Measures on Autistic Children in Behavior Therapy. Journal of Applied Behavior Analysis, 6, 131-166.

Pierce, K., Schreibman, L. (1997). Multiple Peer Use of Pivotal Response Training to Increase Social Behaviors of Classmates with Autism: Results from Trained and Untrained Peers. Journal of Applied Behavior Analysis, 30, 157-160.

Vismara, L.A ., & Lyons, G. L. (2007). Using Perseverative Interests to Elicit Joint Attention Behaviors in Young Children with Autism: Theoretical and Clinical Implications for Understanding Motivation. Journal of Positive Behavior Interventions, 9(4), 214-228.