Previous studies have demonstrated a lower degree of synchronization among activated brain areas in people with autism, as well as smaller size of the corpus callosum, the white matter that acts as cables to wire the parts of the brain together. This latest research shows for the first time that the abnormality in synchronization is related to the abnormality in the cabling. The results suggest that the connectivity among brain areas is among the central problems in autism. The researchers have also found that people with autism rely heavily on the parts of the brain that deal with imagery, even when completing tasks that would not normally call for visualization.
"Human thought is a network property. You think not with one brain area at a time, but with a network of collaborating brain areas, with emphasis on collaborating. In autism, the network connectivity (the bandwidth) through which the areas communicate with each other may be limited, particularly in the connections to the frontal cortex, limiting what types of networks can be used," said Marcel Just, co-author of the studies and director of Carnegie Mellon's Center for Cognitive Brain Imaging.
Both studies focused on people with autism who have normal IQs. In one study, the researchers used functional magnetic resonance imaging (fMRI) to view which parts of the brain were activated in people with autism compared to a control group of normal participants while completing the Tower of London task. In a Tower of London task, participants must -- in a set number of moves -- rearrange the positions of three distinctive balls in three suspended pool pockets to match a specified pattern. This requires a person to strate
Source:Carnegie Mellon University