UAB researchers identify a possible cognitive mechanism at the base of ASD

Researchers at the University of Alabama in Birmingham have identified a possible mechanism of human cognition that underlies autism spectrum disorders, or ASDs.

The diagnosis of ASD is always based on behavior. Psychologists and health professionals with clinical expertise use the Autism Diagnostic Observation Program and the Autism Diagnostic Interview to diagnose autism – both tests are considered the absolute norm.

However, getting a diagnosis can be a longer process due to a number of factors, including lack of resources and qualified clinicians. This delays on average the diagnosis of autism until the age of 5 or 6 years.

"In the field of ASD, two important research questions are: how can we minimize the delay in diagnosis and what kind of intervention can we give to the child?" Rajesh Kana, Ph.D., badociate professor of psychology at the UAB College of Arts and Sciences. "Our results mainly answer the first question, but if the results of a study can be replicated multiple times for reasons of external validity, they can also be used to find answers to this last question."

Postdoctoral researchers Omar Maximo, Ph.D., and Kana, used 306 people aged 8 to 39, including 138 in the ASD group and 168 in the typical developing group. They examined functional connectivity, which refers to the synchronization of activities in different regions of the brain, on two types of networks, unimodal and supramodal, in areas of the brain below the cerebral cortex. The subcortical zones contain structures that receive entrances from the cortex and sensory organs and play an important role in cognitive and social functions.

"Think of the brain network as a system of interconnected roads leading you into the cities.The connections of white matter lead you to different parts of the brain," said Maximo. "Unimodal areas are primarily involved in basic sensory processes, while supramodal areas – a collection of several brain regions – are in charge of higher cognitive processes."

Maximo and Kana found that there was excessive connectivity in unimodal-subcortical connections and sub-connectivity in supramodal-subcortical connections for individuals with ASD, compared to the developing control group typical, suggesting a relationship between connectivity and the expression of ASD.

The study is unique in that it focuses on the subcortical regions of the brain. "We are trying to find the signature of autism and why people with ASD manifest certain social and behavioral symptoms," Kana said. "The way brain structure and function are affected can help us understand why patients with ASD are different."

According to Kana, biomarker research for ASD can greatly help identify individuals early and initiate interventions, such as cognitive-behavioral therapy or the development of the necessary social skills, ultimately by correcting the links between sensory processes and superior sensory processes.