Brain can shut out bad habits

Your brain has the ability to ‘switch off’ bad habits whenever required, according to a new MIT study.

The study by Massachusetts Institute of Technology neuroscientists has found that a small region of the brain’s prefrontal cortex, where most thought and planning occurs, is responsible for moment-by-moment control of which habits are switched on at a given time.

Habits are behaviours wired so deeply in our brains that we perform them automatically. This allows you to follow the same route to work every day without thinking about it.

“We’ve always thought — and I still do — that the value of a habit is you don’t have to think about it. It frees up your brain to do other things,” says researcher Ann Graybiel.

“However, it doesn’t free up all of it. There’s some piece of your cortex that’s still devoted to that control,” he said.

The new study offers hope for those trying to kick bad habits, says Graybiel, senior author of the new study.

It shows that though habits may be deeply ingrained, the brain’s planning centers can shut them off. It also raises the possibility of intervening in that brain region to treat people who suffer from disorders involving overly habitual behaviour, such as obsessive-compulsive disorder. Habits often become so ingrained that we keep doing them even though we’re no longer benefiting from them. The MIT team experimentally simulated this situation with rats trained to run a T-shaped maze.

As the rats approached the decision point, they heard a tone indicating whether they should turn left or right. When they chose correctly, they received a reward — chocolate milk (for turning left) or sugar water (for turning right).

To show that the behaviour was habitual, the researchers eventually stopped giving the trained rats any rewards, and found that they continued running the maze correctly.