Identifying Brain Activity Underlying Symptoms of Autism May Lead to Better Treatments

Identifying Brain Activity Underlying Symptoms of Autism May Lead to Better Treatments

Posted: September 11, 2014

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Marjorie Solomon, Ph.D., recipient of a 2009 NARSAD Young Investigator Grant, supported by a Research Partnership with the Robert, Martha and John Atherton Foundation, led research at the University of California-Davis (UC-Davis) that has made new connections between the brain and behavior in young adults with autism spectrum disorder (ASD). Learning more about brain function underlying behavioral symptoms is an essential step toward developing more effective treatments.

The research involved 47 participants aged 18 to 40, 22 of whom had a diagnosis of ASD. The study subjects were asked repeatedly to perform tasks that involved selecting pairs of printed characters and receiving feedback indicating whether the pairs they chose were correct or incorrect. The test is designed not just to test accuracy in making selections of varying difficulty in the subjects with ASD vs. typically developing subjects, but also to gauge how well test-takers were able to adjust their responses after receiving feedback. All the while, the brain function of the test-takers was being monitored by fMRI brain imaging.

Going into the study, Dr. Solomon and colleagues were aware of a considerable literature reporting on learning impairments in people with ASD. They observed some of these same impairments in this research, but for the first time they could be correlated with the brain scanning data. As expected, young adults with ASD had difficulty integrating positive feedback in a given trial into their performance on subsequent trials. This was due to deficits in reward-related working memory—the ability to keep just-gathered information at the ready—for application in a related or new situation. Those with ASD “had a tendency to rely more heavily on trial-by-trial feedback processing as opposed to an affective reward-based working memory,” the team reported in a paper appearing August 26th in The American Journal of Psychiatry.

This most essential finding of the research was translated by the team into information about brain function. Working memory problems are traceable to dysfunction in the prefrontal cortex. They report that the resort to trial-by-trial feedback may be a compensatory strategy that is dependent upon engagement of the brain’s anterior cingulate and orbito-frontal cortices.

Most important perhaps are the implications for current and future interventions. Psychosocial and neural retraining, the team said, as well as interventions involving psychotherapy and medication, might improve the ability to retain feedback-related information and learn more efficiently, provided they enhance the brain’s reward system (for instance by centering on the release of the neurotransmitter dopamine). The research also calls attention to the importance of exaggerated efforts to deliver positive feedback and rewards for patients with ASD.

"We are very excited about these findings which begin to illuminate some of the reasons that individuals with ASD are inefficient learners, and will help us to devise better ways to help them,” commented Dr. Solomon, Associate Professor of Clinical Psychiatry at the MIND Institute at UC-Davis Medical Center. “We also are extremely grateful to the Brain & Behavior Research Foundation and the Athertons for providing us with support to develop this promising line of research."

Other researchers on the team included Tara A. Niendam, Ph.D., a 2012 NARSAD Young Investigator Grantee; senior team member Cameron S. Carter, M.D., a two-time NARSAD Grantee (1997 and 2007); and J. Daniel Ragland, Ph.D., a 2004 NARSAD Independent Investigator Grantee, all of UC Davis.

Read the abstract of this research paper.