Your lazy brain actually changes how you see the world to discourage you from effort, a new study found. The results suggest that the amount of work required to achieve a task changes our perception of it — in essence, our brain makes anything challenging seem less appealing.

Something tells me we’re not the only species to have this bias.
Image credits Dimitris Vetsikas.

Today was to be the day. You made a commitment to yourself — today, you’d replace the after-work couch and chip marathon with a healthy dose of jogging. You bought the sneakers, put together the mother of all jogging playlists, and had the route all planed. It would be the dawn of the new, fitter you.

So how on Earth did you end up on the couch munching on snacks again?

Blame the brain

A new paper from the University College of London found that your brain just won’t let you put the effort in. The estimated amount of work required to do a task influences the way we perceive it, making us choose the path of least resistance.

“Our brain tricks us into believing the low-hanging fruit really is the ripest,” says Dr Nobuhiro Hagura, who led the UCL study before moving to NICT in Japan.

“We found that not only does the cost to act influence people’s behaviour, but it even changes what we think we see.”

The team had 52 participants undergo a series of tests in which they had to judge the direction a bunch of dots moved on a screen. They would input their answer by moving one of two handles — one held in the right hand, the other in the left.

At first, these two handles required an equal amount of effort to move. But as the tests progressed, the researchers gradually added a load to one of the handles to make it more difficult to move. They report that the volunteers’ responses became gradually more biased towards the free handle as the load increased, even though the dots’ patterns of movement weren’t altered. For example, when weight was added to the left handle, they were more likely to judge the dots as moving to the right — because this answer was easier to express.

When asked about their choices, the participants reported they weren’t aware of the increased load on the handle. This suggests that their movements adapted automatically, which in turn changed their perception of the dots.

“The tendency to avoid the effortful decision remained even when we asked people to switch to expressing their decision verbally, instead of pushing on the handles,” Dr Hagura said.

“The gradual change in the effort of responding caused a change in how the brain interpreted the visual input. Importantly, this change happened automatically, without any awareness or deliberate strategy.”

Matter over mind

“That seems like a lot of work. Let’s watch Netflix instead.” — your brain.
Image credits Carlos Barengo.

Dr Hagura further explained that up to now, researchers believed that we made a decision based on our senses and the motor system reacts to that decision — we see a tasty apple in the grocery and we reach out for it. In this case, the motor system plays no part in our choice to act. The paper suggests that this isn’t entirely true. The effort required to complete a task actually changes how we perceive the object of our desire, playing a central role in influencing our decision.

The team believes their findings can be used to shape everyday decisions by making certain choices more effort-intensive.

“The idea of ‘implicit nudge’ is currently popular with governments and advertisers,” said co-author Professor Patrick Haggard from the UCL Institute of Cognitive Neuroscience.

“Our results suggest these methods could go beyond changing how people behave, and actually change the way the world looks. Most behaviour change focuses on promoting a desired behaviour, but our results suggest you could also make it less likely that people see the world a certain way, by making a behaviour more or less effortful. Perhaps the parent who places the jar of biscuits on a high shelf actually makes them look less tasty to the toddler playing on the floor.”

I’m not particularly big on the idea of being “implicitly nudged” and all, I have to admit. But seeing as my brain is already hard at work doing just that, I guess some counter-manipulation wouldn’t be so bad.

So why does it happen? Well, this effect is probably set in place to conserve energy. Our brains evolved over hundreds of thousands of years when access to food wasn’t guaranteed. One of their prime concerns thus is to make sure you put in as much work as you need to survive — but not much more than that.

The full paper “Perceptual decisions are biased by the cost to act” has been published into the journal eLife.