http://www.wrongplanet.net/article419.html
and
http://www.guardian.co.uk/society/2012/ ... =digest_12
"...Asperger’s there is immature development of the cerebellum, amygdala, and hippocampus. Small cells are packed tightly in these immature parts of the brain, signifying true immature development, not damage or atrophy. Brains from people with autism are more immature in hippocampus development than are Asperger’s brains, which may help explain the cognition problems we see in low-functioning autism. The situation is reversed for the amygdala, a part of the brain that processes emotion. Here, the Asperger’s brain is often more abnormal than the autistic brain. Could the more normal hippocampus preserve the cognitive function in Asperger’s, with the less normal amygdala causing the social problems? Corroboration comes from brain scan studies showing that people with Asperger’s or high-functioning autism process emotional information differently than do normal subjects. The British autism researcher Simon Baron-Cohen has done functional MRI studies indicating that normal people activate the amygdala to judge the expression in another person’s eyes, but people with Asperger’s call on fronto-temporal regions of the brain. More recently, a study by Haznedar revealed that in the brain of the high-functioning autistic or Asperger’s person, the circuit between the anterior cingulate in the frontal cortex and the amygdala is not completely connected. As a result, people with autism or Asperger’s have decreased metabolism in the anterior cingulate. "
"The brains of men and women with Asperger Syndrome are more similar to each other than are those of male and female controls, according to a study published in the January issue of the American Journal of Neuroradiology. The results lend support to the extreme male brain’ theory of autism, the researchers say."
"The difference in the volumes of total white matter and local gray matter between men and women is smaller in the group with Asperger syndrome than in controls. This suggests that the brains of women with the syndrome have more male’ brain characteristics than those of controls, the researchers say.
Among controls, the men’s brains also have greater connectivity as measured by the flow of water through the brain than the women’s brains in a number of regions, including the corpus callosum, which connects the two hemispheres. This difference in connectivity between males and females is also smaller among the brains of individuals with Asperger syndrome.
In some of our other investigations we have examined the thickness of cortical areas. We found that in the right hemisphere, the areas associated with social functioning and imitation part of the so-called mirror neuron system have reduced thickness, and that this reduction is also associated with severity of social symptoms in ASD. "
"There are also some important brain areas associated with social functioning that lie below the cortex, in particular the amygdala. This region shows atypical patterns of development in ASD; by adolescence, the smaller size of the amygdala is also associated with severity of social symptoms.
Our functional MRI studies also focus on language and social processing. In our language studies, we find that even in high functioning verbal children and adults with ASD, there are differences in brain activation patterns. Like typical controls, people with ASD process language in the left hemisphere, in the same key areas of the brain. However, the patterns of activation are distributed differently, suggesting that in ASD the brain works differently, and that the language areas are not as well integrated or connected as they are in neurotypical people; such connections are critical for complex language processing, including higher level discourse.
Many studies have investigated how the brain processes faces, a key social stimulus, in ASD. Early studies found the main area for face processing, called the FFA (face fusiform area), was not activated in ASD. However, in our studies we required our participants to look directly at the center of the face while we collected the brain images. This difference in procedure showed that people with ASD do show typical FFA activation when they are attending to the face. Our collaborators at the University of Wisconsin went one step further, measuring where their participants looked, and which areas of the brain were activated, while they were judging emotional facial expressions. They found a direct relationship between FFA activation and amount of time spent looking at the eye region of the faces in their participants with ASD. Across both these studies we also found differences in brain activation in other regions associated with social processing, including the amygdala and the mirror neuron system."
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*Truth fears no trial*
DX AS & both daughters on the autistic spectrum
03 Aug 2012, 5:12 am
