The autistic child had the same size columns as the adult autistic patient," says Buxhoeveden, "suggesting an unusually rapid early development like that seen in Down syndrome."
Because the column units are smaller and more densely packed in these autistic brains, yet the brain size remains the same, the autistic brain appears to contain more of the processing units, says Buxhoeveden. Returning to the computer analogy, he considers the implications: "Computer modeling has shown that having smaller processing units allows for greater fine-tuning of information," he says. "Incoming signals can be distributed over more units, thereby allowing each unit to handle a more specific part of the overall signal."
Such improved processing might manifest as the potential for the great mental capabilities seen in autistic savants, although this is strictly speculative, says Buxhoeveden. "Alternatively," suggests Courshesne, "the smaller mini-columns may have reduced functional capacity, which may explain why autistic children have reduced ability to process complex social and emotional information."
Another group of researchers used neuroimaging coupled with measurements of human behavior to investigate the autistic brain. Nicole Gage, PhD, at the University of California , Irvine , used magnetoencephalography ( MEG ) to explore the neural correlates of sound sensitivity and language deficits in autistic children. Many children with autism are delayed in the development of language, either not speaking at all or with very limited language capability.
Autistic children often also have a peculiar sensitivity to sound. "Autistic people can become quite anxious and upset when they hear certain types of sounds," Gage says. Her goal is to define the brain systems that are responsible
Contact: Leah Ariniello
Society for Neuroscience