News and Notes about Scientific Research on Autism and other Developmental and Behavioral Disorders

Editor: Bill Ahearn, Ph.D., BCBA
Director of Research, The New England Center for Children

Government Developing Autism Research Plan

In 2003, Congress requested that the National Institutes of Health (NIH) convene a panel of autism researchers to assess the current state of autism research and develop a plan to facilitate an understanding of the causes and effective intervention strategies for this spectrum of disorders. NIH’s Interagency Autism Coordinating Committee (IACC) convened this panel and a 10-year research plan covering a variety of goals was developed. This plan, referred to as the IACC Autism Research Roadmap and Matrix, was presented to the public at the Autism Summit Conference held in Washington, D.C. in November. A few NECC administrators and researchers attended this meeting. Many areas of need were identified and both short-term and long-term goals were established for each of these areas.

The general categories of research include better and more accurate descriptions of autism spectrum disorders (ASD); refining diagnostic procedures; determining the prevalence of ASDs; identifying the most effective treatments; and, determining the causes, developmental progression, and long-term prognosis of ASDs. This is not the first major Congressional initiative regarding autism. In 2000, Congress passed the Children’s Health Act in an effort to focus and coordinate NIH’s research efforts. One of the most significant outcomes of the Children’s Health Act has been the establishment of an interdisciplinary network of Centers of Excellence in Autism Research. Among these sites are the University of California, Los Angeles, the Kennedy Kreiger Institute at the Johns Hopkins School of Medicine, and the Boston Medical Center at Boston University. NECC has been contacted by the Boston University group, headed by Helen Tager-Flusberg, to serve as a source of recruiting participants. Over $65 million has been allocated to eight of these Centers of Excellence to conduct basic and clinical research.

Congress has yet to act on the IACC’s Research Roadmap and Matrix, but it is clear that our government is making efforts to accelerate autism research. On the other hand, at least one important issue, how to make effective intervention available to children and families afflicted with ASD, has not yet been formally tackled. There is no question that more autism research is needed. However, without a well-developed plan to make treatment readily available, we may not be allocating our money in the most judicious manner.

National Institute of Mental Health (2003). Autism Spectrum Disorders Research at the National
Institutes of Mental Health. http://www.nimh.nih.gov/publicat/autismresfact.cfm.

For more information on the IACC’s activities visit: http://www.nimh.nih.gov/autismiacc/index.cfm

Readers' Forum

As announced in the last Newsletter, I will be addressing questions that have been brought to me by NECC staff, parents, and friends. I will answer one or two questions per newsletter, depending on available space. Email your questions to Bahearn@necc.org.

Q: I have heard that casein- and gluten-free diets can cure autism, what is the harm of restricting access to these foods for my child?

A: This question has come up quite frequently. Many parents of children with an autism spectrum disorder (ASD) want to make sure that they are doing all they possibly can to help their child. There are many websites that suggest that food allergies or intolerances cause or significantly contribute to autism. Most of these websites also sell (or link to other sites that will) casein- and gluten-free products, but we will not focus of the benefit to those selling these products rather we will look at what is in the best interest of a child with an ASD. For over a decade I have worked with children with feeding difficulties with and without ASDs and one frequently encountered causes of a child's feeding problem is food allergy. If a child has a documented food allergy then removing the allergen(s) from the child's diet is a necessary first step. Most children with a significant food allergy appear sickly, have symptoms that are typical of an allergic reaction, may vomit frequently, and often have abnormal bowel movements. Shortly after the food the child has an allergy to is ingested, symptoms (e.g., diarrhea, swelling in the mouth area, difficulty breathing, pronounced rashes especially in the face or torso) appear. Most children outgrow their allergies although it is thought that allergies to nuts (and peanuts), fish, and shellfish are likely life-long allergies. If a child is suspected of having an allergy because of symptoms, then there are two tests commonly accepted as valid means of diagnosing food allergy. These are the skin prick and RAST (radioallergosorbent) tests. These tests are then combined with information gathered by alternately exposing or restricting access to the suspected allergen. So back to the point of the question, why not restrict access to casein and gluten? First, children with ASD are prone to selective eating and the food group that they are most likely to consume is starch (Ahearn et al., 2001). Gluten is a constituent of many starches and if we remove the most preferred foods from a child's diet who is already selectively eating then we will likely be making this problem much worse. Because children with ASDs are prone to selective eating it is probably a good idea to attempt to expand their diets rather than restrict them. Finally, children with ASDs are no more likely to have gastrointestinal difficulties, including food allergies, than are typically developing children (Black, Kaye, & Jick, 2002). These points taken together with the lack of sound scientific evidence supporting casein- and gluten-free diets imply that such diets should be avoided unless the child has a documented food allergy.

For more sound information about food allergies, go to the National Library of Medicine’s food allergy site at: http://www.nlm.nih.gov/medlineplus/foodallergy.html

Ahearn, W.H., Castine, T., Nault, K., & Green, G. (2001). An assessment of food acceptance in
children with autism or pervasive developmental disorder - not otherwise specified. Journal of Autism and Developmental Disorders, 31, 505-512.

Black, C., Kaye, J., & Jick, H. (2002). Relation of childhood GI disorders to autism: Nested
case-control study using data from the UK General Practice Research Database. British
Medical Journal, 325, 429-421

Research at The New England Center

Editor's note: The New England Center for Children has recently published two articles in the Journal of Applied Behavior Analysis in a special issue on translational research. Translational research is a relatively new term that has emerged in behavioral and biomedical science referring to lines of research that integrate basic and applied science. The New England Center for Children has a long tradition of supporting basic science because we have assumed that discovering or delineating basic principles of behavior will eventually translate into gains in our service delivery. One example of this is apparent in the discrimination studies conducted over the last two decades by our colleagues from the Shriver Center. Cam Johnson, Sue Langer, Becky MacDonald, and others have translated the compiled knowledge gained from this basic research to develop the NECC’s discrimination curriculum.

Ahearn, W.H., Clark, K.M., Gardenier, N.C., Chung, B., & Dube, W.V. (2003). Persistence of stereotypic behavior: Examining the effects of external reinforcers. Journal of Applied Behavior Analysis, 36, 439-448

Previous basic research has shown that behavioral persistence is often positively related to rate of reinforcement. This relation, expressed in the metaphor of behavioral momentum, has potentially important implications for clinical application. The current study examined one prediction of the momentum metaphor for automatically reinforced behavior. Three children diagnosed with an autism spectrum disorder who engaged in stereotypic behavior maintained by automatic reinforcement participated. Two experimental conditions were compared; each condition involved a sequence of four sessions. In the Added Stimulus Condition, the four sessions were conducted in the following order: (a) Baseline, (b) Baseline plus preferred stimuli delivered on a variable time schedule, (c) Test of behavioral persistence, and (d) Baseline. In the Control Condition, the four sessions were conducted in the following order: (a) Baseline, (b) Baseline, (c) Test of behavioral persistence, and (d) Baseline. Stereotypy was more persistent in the Added Stimulus condition relative to the Control condition for each participant. The implications of these findings for the treatment of automatically reinforced behavior with interventions such as noncontingent reinforcement are discussed.

Keywords: Behavioral momentum, automatic reinforcement, resistance to change, stereotypy, autism

Roscoe, E.R., Iwata, B.A., & Rand, M.S. (2003). Effects of reinforcer consumption and magnitude on response rates during noncontingent reinforcement. Journal of Applied Behavior Analysis, 36, 525-539

Results of previous research on the effects of noncontingent reinforcement (NCR) have been inconsistent when magnitude of reinforcement was manipulated. We attempted to clarify the influence of NCR magnitude by including additional controls. In Study 1, we examined the effects of reinforcer consumption time by comparing the same magnitude of NCR when session time was and was not corrected to account for reinforcer consumption. Lower response rates were observed when session time was not corrected, indicating that reinforcer consumption can suppress response rates. In Study 2, we first selected varying reinforcer magnitudes (small, medium, and large) on the basis of corrected response rates observed during a contingent reinforcement condition and then compared the effects of these magnitudes during NCR. One participant exhibited lower response rates when large-magnitude reinforcers were delivered; the other ceased responding altogether even when small-magnitude reinforcers were delivered. We also compared the effects of the same NCR magnitude (medium) during 10-min and 30-min sessions. Lower response rates were observed during 30-min sessions, indicating that the number of reinforcers consumed across a session can have the same effect as the number consumed per reinforcer delivery. These findings indicate that, even when response rate is corrected to account for reinforcer consumption, larger magnitudes of NCR (defined on either a per-delivery or per-session basis) result in lower response rates than do smaller magnitudes.

DESCRIPTORS: noncontingent reinforcement, reinforcer magnitude, satiation

Web Resources

For information about the New England Center or to access and electronic version of this or previous NECC Research Newsletters, visit our Web site www.necc.org.

For information about autism, visit the National Library of Medicine’s autism site www.nlm.nih.gov/medlineplus/autism.html.

For information about applied behavior analysis in the treatment for autism visit www.behavior.org.

For science-based information on biomedical treatments and theories in autism visit www.autism-biomed.org.

For information on health issues in general visit the World Health Organization www.who.int.

For professionally-screened information on health care (including some treatments for autism and other developmental disabilities), visit www.quackwatch.com.

For information on the Berkshire Association for Behavior Analysis and Therapy, visit http://www.karsina.us/babat/.

For information on the Association for Behavior Analysis, visit http://www.abainternational.org/.




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