This month's Society for Neuroscience Conference in New Orleans unveiled the latest research into some of what goes on in our brains.
The science behind our smiles
Researchers announced the results of studies determining how the brain processes facial expressions and emotions. In monkeys, for example, it was discovered that special neurons in the brain's amygdala -- the part of our brain that deals with emotion -- respond differently when monkeys look at a smiling primate versus a neutral-faced primate. Principal investigator Katalin Gothard, M.D., Ph.D., from the University of Arizona, said that because "normal social behavior depends on the activity of [neurons] ... It is not surprising that in many brain disorders associated with abnormal amygdala function, such as schizophrenia or social anxiety, eye contact and social interaction is impaired."
In humans, researchers found that smile mimicry might depend on social status. People deemed powerful often suppressed a smile toward peers, while powerless people returned everyone's smile regardless. Researchers also found that crow's feet around the eyes aren't enough to deem a smile authentic. You may be able to tell who's bluffing by mimicking that person's smile and seeing what feelings come up for you.
How we make social decisions
Researchers looking at the "social brain" in humans and primates -- the structure of our minds that helps us understand people's intentions, beliefs, desires and how to behave appropriately -- studied human sharing and altruistic behavior. They found that we have different areas of our brain that deal with altruism when it's rooted in general concern and altruism when it's rooted in preserving our reputation.
Rewiring the brain after trauma
Scientists studying mice for more insight into what goes on in the brains of post-traumatic stress disorder patients think they have discovered how the brain disposes of the kinds of bad memories associated with PTSD and other similar cognitive disorders. They noted that the antidepressant ketamine, as well as the turning on and off of the brain's dopamine neurons in the brain's reward center, can cue symptoms to leave. Other research looked at the brains of teenagers before and after the 2011 Japanese earthquake and found that brains with weak connections in certain areas could be at a high risk for PTSD and anxiety after a traumatic experience. Studies in mice revealed that repetitive violent and competitive engagements change the brain's chemistry.
New tools to fight Alzheimer's
New developments presented at the conference include PET scanning to monitor changes in brain function before Alzheimer's symptoms occur and a new drug tested on mice that targeted the biochemical changes in proteins thought to occur in dementia patients. Also, a probe that uses nanotechnology and MRIs is thought to be able to distinguish between diseased and non-diseased brain tissue, thus aiding early diagnosis.
With the elderly population growing, Alzheimer's disease, which is the most common cause of dementia, is a new epidemic currently affecting 5 million people in the United States alone. The number is predicted to increase to 13 million people by 2015. metro/lc