A recent study has found that brains of individuals with autism show differences in connectivity that vary by region. The largest study to explore connectivity differences in autism brains revealed both unusually strong and weak connections in various regions. The study analyzed brain scans from nearly 2,000 participants, including 841 autistic individuals and 984 controls from four ongoing studies of autism. The findings suggest that autistic people have biologically relevant differences in brain connections.
The study found that individuals with autism have more connections in the frontal and parietal cortex compared to controls. These regions are responsible for various aspects of complex thought. On the other hand, autistic individuals have fewer connections between the sensorimotor and temporal cortex, which are involved in sensory stimuli processing, movement, and sound and language processing. Similar patterns were observed in scans from two other studies, while a fourth set of scans showed increased connectivity in the frontal and parietal areas but no decrease in the sensorimotor and temporal regions.
Overall, the degree of connectivity is preserved in autism, but the pattern of connectivity is altered. The study also revealed that connectivity patterns in autism are not influenced by age, sex, or medication use. However, limited speech, communication difficulties, and challenges in daily living skills are associated with specific connectivity patterns. Interestingly, no link was found between connectivity differences and scores on the Autism Diagnostic Observation Schedule (ADOS), which is the gold-standard method for rating autism traits.
Although the reported associations between connectivity patterns and autism traits are weak, experts suggest that assessing the strength of each connection and measuring simultaneous activity of brain areas may reveal stronger associations with autism-related behavior or clinical aspects. The research team plans to use more refined methods to acquire and analyze brain imaging data in the future, with the aim of tracking how functional connectivity changes over one to two years.
