Unique Folding Patterns in Autism Brains
Recent studies have shown that the brains of children with Autism Spectrum Disorder (ASD) fold differently than a normal brain—either being unusually smoother or unusually convoluted depending on location and age. Researchers measure the development of neural tissue folds in the cortex as changes in the local gyrification index; a ratio which compares the area of the smooth outer surface with that of the inside the sulci. Using this information, researchers can understand the link between autism and the folds of a brain.
In a study at San Diego State University, it was found that school-age children and adolescents with autism had more intricately folded regions. The left temporal and parietal lobes, which are responsible for processing sound and spatial information, were shown to have these intricate folds in children with autism. Research also found increased gyrification in the right temporal and frontal lobes, which are responsible for decision making and motor skills. In contrast, a second study found that preschoolers with autism do not show this degree of intricate folding unless they had enlarged brains. Preschoolers with autism were also found to have an unusually smooth region in the occipital lobe (specifically in the region dedicated to recognizing faces). These studies, in juxtaposition, demonstrate that brain folding hints at the different developmental path that autism brains follow when compared to normal brains. According to Ruth Carper, a researcher at San Diego State, “many of the brain areas with exaggerated folding are among the earliest to develop folds during gestation.” Thus, the folding will increase in intricacy and convolution over time due to this developmental disruption. In another study at the University of California, Davis, researchers found that children with enlarged brains actually have a specific subtype of autism due to the fact that only children with enlarged brains exhibited this degree of increased and atypical folding. This study adds to the evidence that folding patterns depends on the development of the individual and where that individual lies within the autism spectrum.
It’s clear that ASD is a very complex subset of conditions and traits that are influenced by various genetic and environmental factors. A great deal of research is focused on identifying physical differences, such as brain folding patterns, which are present in the autistic brain. In doing so, resources may be found to aid and benefit a developing brain with ASD. Lastly, such research will only further our understanding of how all of our brains grow and evolve over time.
Writer: Ava Genovese
Editor: Farwa Faheem