Cornucopians and doomers explained. It's bred in the brain. [View All]

Brain 'rejects negative thoughts'

A study, published in Nature Neuroscience (GG: entitled "How unrealistic optimism is maintained in the face of reality"), suggests the brain is very good at processing good news about the future.

However, in some people, anything negative is practically ignored - with them retaining a positive world view.

They rated 14 people for their level of optimism and tested them in a brain scanner.

When the news was positive, all people had more activity in the brain's frontal lobes, which are associated with processing errors. With negative information, the most optimistic people had the least activity in the frontal lobes, while the least optimistic had the most.

It suggests the brain is picking and choosing which evidence to listen to.

Unrealistic optimism is a pervasive human trait that influences domains ranging from personal relationships to politics and finance. How people maintain unrealistic optimism, despite frequently encountering information that challenges those biased beliefs, is unknown. We examined this question and found a marked asymmetry in belief updating. Participants updated their beliefs more in response to information that was better than expected than to information that was worse. This selectivity was mediated by a relative failure to code for errors that should reduce optimism. Distinct regions of the prefrontal cortex tracked estimation errors when those called for positive update, both in individuals who scored high and low on trait optimism. However, highly optimistic individuals exhibited reduced tracking of estimation errors that called for negative update in right inferior prefrontal gyrus. These findings indicate that optimism is tied to a selective update failure and diminished neural coding of undesirable information regarding the future.