Often a bad thought comes to us just like a boring melody and attempts to suppress it end in vain.

According to new research, this is because unwanted thoughts are stored in other parts of the brain, so “getting rid of” them is a futile strategy.

To determine how we (could not) manage to suppress unpleasant thoughts, scientists asked 15 people to first imagine a red apple or green broccoli and then not think about these things for 12 seconds. In parallel, participants’ brain activity was monitored.

Eight out of 15 people said they had successfully suppressed imaginary pictures of fruits and vegetables, although observations on their brains showed a completely different result.

Using magnetic resonance imaging (MRI) techniques, scientists have discovered “where thinking came from.” The left side of the brain was activated when presenting fruits or vegetables voluntarily, and the right side when trying to suppress it.

“Using this algorithm, we can see that people can imagine images even when they do not know it,” said Roger Koening-Robert, a cognitive neuroscientist at Monash University.

When participants thought they had successfully avoided thoughts about apples and broccoli, a visual image of these thoughts was still visible in the brain scan results.

The visual cortex is the part of the brain that is responsible for the imagination. It generates thoughts beyond consciousness. As a result, these thoughts arise in our minds even when we try to stop them. All of this makes our subjective experience even more convincing that it is very difficult to stop bad thoughts.

It should also be noted that “suppression of thoughts” means getting rid of them and does not mean replacing them with new thoughts or diverting attention. Even in this case, scientists are not sure that their 15 participants did not try to divert attention to other ideas. Further studies are needed in which more people will be involved.

A study by the same group in 2019 showed that replacing thoughts works better than suppressing thoughts.

Of course, thinking about apples and broccoli while watching your brain is a little different from the situation when unwanted thoughts interfere with your daily life, although this study brings us a little closer to understanding what is going on in the human brain.