Research > Biological Markers of the Austic Disorders

Biological Markers of the Autistic Disorders

Principal Investigator: Jerome Kagan, PhD

About the Principal Investigator

Jerome Kagan is a retired Daniel and Amy Starch Professor of Psychology at Harvard University and Senior Scientist at Judge Baker Children's Center.

Professor Kagan is also the former director of the Mind/Brain Behavior Interfaculty Initiative. He has served on the National Institute of Mental Health and on the National Research Council. His books include Galen’s Prophecy: Temperament in Human Nature and Three Seductive Ideas.

Professor Kagan's research, on the cognitive and emotional development of a child during the first decade of life, focuses on the origins of temperament. He has tracked the development of inhibited and uninhibited children from infancy to adolescence. Kagan’s research indicates that shyness and other temperamental differences in adults and children have both environmental and genetic influences.

Project Description

Judge Baker’s Dr. Jerome Kagan and Dr. Nancy Snidman, in conjunction with Dr. Martha Herbert from Mass General Hospital (MGH) and Dr. Katherine Martien from MGH’s Ladders (Learning and Developmental Disabilities Evaluation and Rehabilitation Services) Clinic, are beginning to study the brain processing mechanisms in children with autism and young children at risk for autism with the hope of gaining a better understanding of the disability.

Autism is a complex developmental disability with different causes that affects the normal functioning of the brain and behavior. The symptoms of autism typically appear at about two years of age and impact the development of social and communication skills. Although there is no cure, there are various treatment options. Unfortunately, there is no medical test that can diagnose a particular form of autism. Most commonly, the diagnosis and treatment of any form of autism rely only on behavioral characteristics.

Over the past few years and with the help of new technology, researchers have begun focusing on the brain to learn more about autism. Judge Baker’s new project, funded by Cure Autism Now, the National Alliance for Autism Research and the Commonwealth Fund, aims to study basic brain processing in subjects with autism, with the long term goal that these studies will determine predictors of autism that may help doctors diagnose the disability at an earlier age.

The researchers are wondering: In what ways do autistic children interpret information differently from children without autism? Are there biological indicators that may make it possible to diagnose or predict autism at a younger age? In order to answer these questions, one project is going to study the brain activity of 50 autistic subjects, ages 3 to 8 years old. The study will also include a control group of children who have not been diagnosed with autism. “We are trying to understand the differences in brain patterns between the autistic children and the children in the control group. Does the brain detect changes in visual and auditory stimuli differently in the two groups?” said Dr. Nancy Snidman.

All physiological testing will be done at Judge Baker, using non-invasive caps that, when placed on a child’s head, allow the researchers to monitor brain activity. Each child will be exposed to auditory (tones and speech) and visual (flashes of light) stimuli to see how the brain reacts to both intense and small changes in the stimulus patterns. For example, the subject may listen to a voice saying “pa” many times followed unexpectedly by the sound “ga”. The brain should detect the change in the sounds, but the brain’s reaction may be distinct in autistic children.

A sub-project of the study goes one step further and will conduct the same procedures on the younger siblings of the subjects with autism. This project was developed because autism may be a heritable disability and the siblings of children with autism are 8 times more likely to be diagnosed themselves. It is possible that the young subjects, ages 3 months to 3 years, may have brain processing mechanisms similar to their older autistic siblings. The siblings can also be followed longitudinally to track their developmental health, which will be an important step in autism research.

A main goal of the study is to characterize subgroups of autism. Currently, children diagnosed as autistic may be labeled high functioning or low functioning, but in general little is known about differential causes of autism. The discovery of physiological differences could help doctors diagnose different subgroups of autism. “If we don’t understand the differences in their brain functioning, it is hard to devise appropriate treatment,” said Dr. Snidman. There may be a way to combine behavioral and physiological measures to give a more accurate picture of the child. This could help doctors come up with more effective and personalized forms of treatment for autistic children. “I regard this research as part of a significant mission that will illuminate the genetically distinct forms of autism,” said Dr. Jerome Kagan.