The Cortical Area of the Brain in Individuals with ASD
People with ASD tend to have thinner cortices and reduced surface area of the brain during adolescences and adulthood while they often have increased cortical development (greater expansion of the cortical surface area) in early childhood (Ha, et. al., 2015).
Individuals with ASD tend to have differences in cortical folding which is how the cerebral cortex is able to grow in size and increase in complexity. This process is essential to the evolution of the mammalian brain especially in humans (Llinares-Benadero & Borrell, 2019). This process just seems to happen differently in individuals with ASD.
Cortical gyrification is related to expansion of the outer cortical layers. It has to do with how the folds of the cerebral cortex that develop assist with the functioning of the individual (Ronan & Fletcher, 2014).
Youth with ASD tend to have enlarged gyrification of the frontal lobe compared to typically developing peers. Specific forms of gyrification, or cortical folding, may actually be associated with intelligence and cognitive abilities (Gregory, Kippenhan, Dickinson, Carrasco, Mattay, Weinberger, & Berman, 2016).
Cortical gyrification changes across the lifespan of the individual with ASD. Both genetic and environmental influences can impact the structure of cortical regions of the brain.