Politically conservative views correlated with larger amygdala, smaller anterior cingulate cortex


Scientists have found that people with conservative views have brains with larger amygdalas, almond shaped areas in the centre of the brain often associated with anxiety and emotions.
On the otherhand, they have a smaller anterior cingulate, an area at the front of the brain associated with courage and looking on the bright side of life. [...]

The results, which will be published next year, back up a (different) study that showed that some people were born with a “Liberal Gene” that makes people more likely to seek out less conventional political views.
The gene, a neurotransmitter in the brain called DRD4, could even be stimulated by the novelty value of radical opinions, claimed the researchers at the University of California. (via.)


Atypical Brain Functioning in Siblings of Autistics


Relative to the other groups, there was reduced activity in specific brain regions in children with ASD when they were watching biological motion compared with scrambled motion.

These included the right amygdala and the ventromedial prefrontal cortex, areas which other research has identified as having changed activity in adults with ASD.

The researchers found additional brain regions that showed reduced activity in both the siblings group and the ASD group, relative to the typically developing group.

They interpreted this result as a reflection of the underlying genetic vulnerability that the siblings group might have to ASD.

The scientists also found what they called “compensatory activity” in the siblings group – brain regions that were working harder than normal and might be helping the children overcome their increased genetic risk of ASD.

These included the right posterior temporal sulcus and the ventromedial prefrontal cortex, which have been implicated in social perception and social cognition. [...]

“More controversially, the authors also propose that other brain regions are under-responsive to biological motion in siblings of children with autism, as well as in those with autism.”

“Yet other regions are reported to be overactive in the siblings, and this is interpreted as compensatory activity.
“Since these siblings had no subclinical symptoms of autism, and were selected to have no other relatives with any autistic features, they are unlikely to constitute a group with strong genetic risk for autism, and so this aspect of the results is puzzling and it would be important to replicate it in another sample.” (via.)

It’s interesting that while autistics show below normal activation in the ventromedial prefrontal cortex, that their siblings showed above normal activation in the same region while viewing “biological motion.”

It’ll be interesting to see what mysteries of the human mind will be revealed as the diagnostic criteria for what exactly defines the autistic spectrum becomes more refined. Supposedly these autistic children didn’t have any other relatives showing symptoms of autism, however, wouldn’t it be interesting to find out whether their relatives show this same abnormal overactivation in said regions.


Brain abnormalities in adolescents with substance abuse & conduct disorders


The scientists, including collaborators at the University of Colorado at Boulder and the University of Maryland, studied 20 adolescent boys. On average they had been on probation 139 of the last 180 days; 19 of the 20 had the psychiatric diagnosis of conduct disorder, and all had diagnoses of substance use disorder. They had been abstinent, however, an average of about five weeks when studied. They were compared with 20 other boys who did not have serious antisocial or drug problems, but who were of similar age, ethnicity, and home neighborhoods.

All played a computerized risk-taking game that repeatedly presented a choice between a cautious and a risky behavior: press the left button and always win one cent, or press the right button and either win five cents or lose ten cents. The scientists examined brain activation with functional magnetic resonance imaging (fMRI) as the boys decided to press right or left, and then as they experienced wins or losses after right presses.

Brain activation differed dramatically in the two groups. The anterior cingulate cortex monitors changing rewards and punishments, and then sends that information to another brain region (dorsolateral prefrontal cortex), which regulates one’s choices among possible behaviors. During decision-making, antisocial boys had significantly less brain activity than normals in both of those regions, and also in other decision-making areas (orbitofrontal cortex, amygdala, insula).

via.