Brain Connectivity Associated with Autism

According to the latest report from the Centers for Disease Control and Prevention, one in 68 children have autism. The latest estimate is roughly 30 percent higher than the center’s 2012 measure, which found that one in 88 children had autism, based on health and education records.

Researcher Inna Fishman is interested in how different parts of the brain communicate with each other, and how these connections develop across childhood and adolescence.

Through this developmental lens, the San Diego State University psychology research professor hopes to understand the typical and atypical patterns of brain organization and brain connections that give rise to either normative, or abnormal behaviors, especially in the sphere of social behavior such as interacting with or understanding of others.

“Social skills and the ability to navigate the social world are quite impaired in autism, a neurodevelopmental disorder with an alarmingly growing prevalence. However, scientists do not have a firm understanding yet of what brain processes cause that deficiency. In order to be able to develop effective interventions, we need to first understand what the underlying brain patterns are that give rise to those behaviors,” Fishman said.

Fishman has utilized several brain imaging methods with different populations who have varying “sociability,” including typical extraverts or introverts, individuals with Williams syndrome known to have hypersocial behavioral tendencies, and most recently — as part of a four-year grant totaling $600,000 from the National Institute of Mental Health — children and adolescents with autism spectrum disorder who have stark social deficits.

Brain network communication

In her study published this week in The Journal of the American Medical Association Psychiatry, Fishman used functional magnetic resonance imaging (fMRI) to map out brain networks that are thought to support human social behavior and the understanding of others. She compared the strength and the extent of the connections within and between these networks in adolescents with autism spectrum disorder and in age-matched peers who do not have the disorder.

In adolescents with autism, Fishman found two networks were communicating with each other at a greater extent than in their typically developing peers. Moreover, the extent of this “cross-talk” between the two networks was strongly linked to the amount of autistic symptoms observed.

The findings lead Fishman to believe that at least by the time children with autism reach adolescence, the brain circuits promoting social functioning are compromised and function less efficiently.

“Identifying these patterns is a first step toward developing effective treatments, such as neurofeedback-based training, that may alleviate some of the autistic symptoms by ‘training’ the affected brain circuits that are involved in social processing, just like one trains one’s muscles,” Fishman said.

Overall, this study demonstrates that brain circuits of individuals with autism are less mature, less efficient and less specialized, even at this relatively late stage of brain development, and that this delayed maturation can explain the behavioral symptoms observed in this disorder.

Clinical and cognitive neuroscience at SDSU

Fishman, along with SDSU psychology professor Ralph-Axel Müller and a team of researchers, work to address some of the most urgent challenges in basic science and the social sciences as part of one of SDSU’s areas of excellence.

Aligned with the White House BRAIN initiative, the research area of clinical and cognitive neuroscience at SDSU advances the university’s contributions to the understanding and treatment of brain-based disorders such as autism, aphasia, fetal alcohol spectrum disorders and Alzheimer’s disease.