How the brain processes bad news


A study conducted by Ryota Kanai showed that as we go through life, most of us hear the good news more than the bad, the flattering more than the insulting.  Moreover, we shape our beliefs based on that bias.  This was discovered by administering trans-cranial magnetic stimulation (TMS),  which sent magnetic pulses into the brains of the participants in the research.

This effect appears in many ways. For example, we change our self image when we are told we are smarter or better-looking than we thought.  However,  if we hear we are more stupid and uglier than we supposed we are less likely to update that image.  Statistics show that about 80% to 90% of us behave this way.

What neuroscientists call the “good news/bad news effect” has its own advantages and disadvantages. In building beliefs predominantly on good news, we lean towards an optimistic view of life which is good. What is even more, we are less anxious of the likelihoods of unpleasant events such as cancer, burglary, internet fraud, missing a flight, divorce, etc..

However, there is a cost to this positive view of the world, because ignoring bad news can be dangerous. It can make us overconfident and even reckless and, as a result, it might leave us unprepared for a natural disaster, naive to the dangers of contracting disease, or oblivious to the warning signs of impending financial crisis.

A team of neuroscientists at University College London has conducted a series of experiments trying to explain how this preference for good news arises in the brain. They found out that through disrupting the function of the small brain region they could neutralise the bias and make people as open to bad news as they were to good.

The cognitive neuroscientist Tali Sharot and others selected 30 right-handed people aged 20 to 35 and divided them into three groups of 10. Each of the subjects received a 40-second blast of transcranial magnetic stimulation (TMS). It sent magnetic pulses into the head and disrupted different parts of their brains. In one group, the TMS was aimed at a part called the left inferior frontal gyrus (IFG), in another at the right IFG, and in the third, the target was a control region of the brain, where the pulses were not supposed to have much effect.

Within half an hour of the TMS session, the subjects sat down at a computer which showed them 40 things nobody wants to happen in their lives, for example developing cancer, having a car stolen, or missing a flight. Then the subject had to predict how likely the event was to happen to them. As they provided their answer, the computer showed the average risk for a person in a similar socioeconomic situation. For instance, you may think that your lifetime risk of cancer is one in 10 but the average is closer to one in three.

Then a second session followed but this time the participants were given the same bad situations and had to estimate again the chance that each event would happen to them at some point. The scientists then analysed the results to see how people’s views changed after they had been given accurate information.

The results showed that those who had magnetic stimulation to the right IFG, or a control part of the brain, showed the usual good news bias. They changed their beliefs more on hearing good news, such as a lower risk of cancer or Alzheimer’s than they originally thought. On the other hand, stimulation of the left IFG destroyed the bias and those respondents were just as likely to shift their views based on bad news as good.

According to Sharot, whose study appears in Proceedings of the National Academy of Sciences, the left inferior frontal gyrus is normally inhibiting other parts of the brain from learning from bad news. However by interfering with the left IFG this inhibition is released.

The left IFG is unlikely to have sole responsibility for the good news bias since the neurons there are connected to many other regions of the brain. It is hard to stop one part of the brain from functioning without affecting others which means that the effect more likely is triggered by a larger neuronal network.

In conclusion, probably it is not a good thing to try to base our views more on a bad news. The reason for that is the fact that the optimists’ view of life is good for our well-being and helps to motivate us. And here’s where the study might be helpful. – to understand how the brain goes wrong, you should first find out how it goes right.


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