Humans tend to remember good news and attenuate the bad: our brains filter the two, and make us remember positive things more strongly than negative. It's a standard human trait—and now scientists understand how it happens.
A team of researchers from University College London have been experimenting with magnetic field brain stimulation, and found that they can easily turn off the rose-tinted-glasses effect. They've found that by stimulating a brain region called the left inferior frontal gyrus (IFG), they can remove the brain's bias, making it equally receptive to good or bad news.
The team used transcranial magnetic stimulation (TMS) to temporarily shut off either the left IFG, right IFG, or another part of the brain in 30 volunteers. Then they asked the participants questions about their chances of experiencing nasty fates—being robbed, contracting a terminal disease, that kind of thing. A little later they were given more information and asked to reassess their guesses. Optimism bias faded away in those who had their left IFG shut down, but remained in the others.
The results, published in the Proceedings of the National Academy of Sciences, are the first time scientists and psychologists have had firm, causal evidence to prove that it's this region of the brain which makes us remember good news more strongly. Even so, it's interesting to see that 40 per cent of the patients who had their left IFG shut down still showed some bias—it was just much lower than in the control participants. That suggests that some people find it easier than others to block out bad news.
Regardless of that little quirk, the finding promises to open up plenty of routes for new research, not least of which is understanding depression better. You see, good news bias is less common in those with depression—so by understanding how the brain works when it functions properly, scientists might be better placed to help those who aren't quite so lucky. [PNAS via The Scientist]
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