Does ‘laziness’ start in the brain?

10 hours ago 9

We all know people with very different levels of motivation. Some will go the extra mile in any endeavour. Others just can’t be bothered to put the effort in. We might think of them as lazy – happiest on the sofa, rather than planning their latest project. What’s behind this variation? Most of us would probably attribute it to a mixture of temperament, circumstances, upbringing or even values.

But research in neuroscience and in patients with brain disorders is challenging these assumptions by revealing the brain mechanisms that underlie motivation. When these systems become dysfunctional, people who were once highly motivated can become pathologically apathetic. Whereas previously they might have been curious, highly engaged and productive – at work, in their social lives and in their creative thinking – they can suddenly seem like the opposite.

For example, in my clinic, I saw a young man called David who had been a high-flyer in his firm but suddenly lost interest in his job as well as the people around him. Previously, he’d been a productive and outgoing person who always seemed to take the initiative at work and in his social circle, but now David did very little and didn’t seem to care. As he put it, he “just couldn’t be arsed”. Eventually, he was fired from his job but reacted with complete indifference. He couldn’t even be bothered to register for unemployment benefit. Seeing that he was unable to pay his rent, David’s friends offered him a room in their house. They soon regretted it. He did nothing all day, waiting for his mates to come home to cook for him. His GP tried him on an antidepressant, but it had no effect.

David wasn’t depressed, though. In fact he was quite happy. After looking deeper into his case, we discovered that the cause was actually two tiny strokes, one on each side of the brain. These were located in the basal ganglia, nuclei that are crucial for motivated behaviour. Research in animals and humans has shown that the basal ganglia connect our needs and wants to actions.

When the basal ganglia are dysfunctional, people don’t initiate actions even though they are able to do so if they are prompted. David, for example, could put the rubbish out or clean the house if he was asked. But left to his own devices he did nothing. Studies in people who develop apathy have shown that many of them just don’t find it sufficiently rewarding to take action. The cost of making the effort doesn’t seem worth the potential benefit.

In some patients, drugs that boost the dopamine system in the brain can restore motivation. Dopamine plays a key role in the reward system of the brain – but whereas previously neuroscientists thought it was a chemical associated with pleasure, recent research shows that it works by driving “want” – incentivising people to seek the outcomes they find rewarding. David was successfully treated in this way: his motivation levels went back up after taking a drug that stimulates dopamine receptors in the brain. Because of this, he was able to get a new job, become independent and even find a partner, something he would never have bothered to do when he was in his apathetic state.

The lessons from patients such as David can be applied to healthy people who experience apathy. At Oxford University, we scanned the brains of students with contrasting contrasting levels of motivation – from extremely motivated to severely apatheticlevels of motivation from extremely motivated to severely apathetic. We found significant differences in how their brains looked. That’s not, in itself, surprising. There’s natural variation in all of the biological systems that make us who we are, with contributions from our different genetics and environment. Intriguingly, though, we saw that the brain regions involved in motivation were working harder in the more apathetic students when we asked them to make choices about whether a particular course of action was worth the effort.

Why might this be the case? We know that almost everyone is willing to work for large rewards. A recurrent finding in apathetic people is that, unlike their more motivated counterparts, they are unwilling to put in the effort when the reward seems small. In our study, we asked people to decide whether to perform a brief action – squeezing a hand-grip at different levels of effort – in exchange for small monetary rewards, represented on the screen by apples. Some choices were obvious: “one apple for maximum effort” (not worth it) or “15 apples for moderate effort” (definitely worth it). But there were less clearcut offers, such as “six apples for 80% effort”. Motivated people decided quickly. Apathetic people slowed down, hesitating far longer over the borderline cases. Their brains had to work more to reach a decision – and thinking hard is aversive, something we tend to avoid if we can.

So deciding whether something is worth the effort seems to tax apathetic people more, meaning they sidestep the decision altogether. When faced with a choice to actually do something, they’re biased towards simply saying “no”.

What does this mean for the supposedly lazy among us, or their friends and loved ones, who might welcome a change of attitude? It’s likely that chiding or haranguing them – as though apathy were a moral choice – isn’t going to work. Instead, researchers are focusing on that reluctance to even think about how worthwhile an activity might be.

One practical way to circumvent this is to make a plan for the day or week ahead. This provides a structured routine that reduces the burden of having to think repeatedly about whether each activity is worth the effort. You make the choices in advance, so that you aren’t waylaid by each one in the moment. Ideally, some of those activities should be personally meaningful and lead to a sense of accomplishment or pleasure. That can help to reinforce the value of engaging in them, making the reward seem larger – which in turn makes the decision easier to say yes to next time round.

In addition, several studies have shown that moving your body can have a positive impact on apathy. Aerobic exercise three times a week for 40-60 minutes, taking dance lessons, or even vigorous walking, can improve motivation, possibly through effects on the brain’s dopamine system. External prompts such as alarms on smartphones or visual reminders (for example, placing running shoes by the door to prompt a visit to the gym or a run) can also be effective in cueing actions.

The ultimate goal of these types of intervention is to work with the brain, making use of what we’ve discovered about the roots of apathy – partly through understanding unusual cases like David’s. The key to changing everyday behaviour is to make the evaluation of costs (effort) and benefits (rewards) a habit that doesn’t seem too much like hard work. Even for the most apathetic among us, this holds out the hope of turning a kneejerk “no” into an ability to consider saying “yes”.

Masud Husain is a professor of neurology and cognitive neuroscience at the University of Oxford and author of Our Brains, Our Selves (Canongate).