We all know the feeling: we want to do something, but something stops us. For most people, it's just putting things off for a little while. But for people with depression or schizophrenia, it's much harder to start doing things. This is called avolition. The brain's mechanisms for this have not been well understood.

Researchers at Kyoto University found a brain pathway that acts like a brake on motivation when things are unpleasant.

This pathway connects two parts of the brain: one that helps us want to do things and another that helps us turn wanting into doing. When we don't want to do something, the first part can stop the second part from working. The researchers thought that when things are unpleasant, this pathway might stop us from starting to do things.

The researchers taught monkeys to make decisions. They gave them choices that had both good and bad outcomes. The monkeys had to decide if the good outcome was worth the bad one. The researchers looked at whether the monkeys wanted to start making decisions at all.

The researchers used a special technique to stop the brain pathway from working.

When they did this, the monkeys were more willing to start making decisions and made them faster when things were unpleasant. This didn't happen when everything was good.

It's important to note that wanting to do something and thinking it's a good idea are not the same. Even when the pathway was stopped, the monkeys still made the same choices. They just started doing things more.

The research also showed that stopping this pathway could help when monkeys got into a rut. If a monkey didn't start a task, it was more likely to not start the next one. Stopping the pathway helped the monkeys get out of this rut and start tasks more often.

The researchers recorded the brain activity and found that one part of the brain became more active when things were unpleasant and after failures. Another part became less active. This is like one part of the brain telling another to stop.

Now that we know which brain circuit controls starting to do things, we might be able to help people with depression and schizophrenia. However, we need to be careful.

The lead researcher said that if we make this pathway too weak, people might do dangerous things. We need to be careful and discuss the ethics of using this knowledge to create treatments.

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Source: Kyoto University