BrainKind Bulletin 004: What does choice overload do to the brain?

Welcome to BrainKind Bulletin - your regular dose of neuroscience research.

The (big?) news:

Researchers have discovered the effect of choice overload on decision-making in the brain.

What did they measure?

They measured what happens to people's brains when forced to make a decision between varying-sized choice sets.

How did they measure it?

Participants were presented with pictures of scenic landscapes that they could have printed on a coffee mug.

Each participant was offered a variety of sets of images, containing six, 12, or 24 pictures and they had to make their decisions while a functional magnetic resonance imaging (fMRI) machine recorded activity in their brains.

As a control, the participants were asked to browse the images again but this time without choosing - and an option was selected for them by an algorithm.

What were the results?

The fMRI scans revealed brain activity in two regions while the participants were making their choices: the anterior cingulate cortex (ACC), where the potential costs and benefits of decisions are weighed, and the striatum, a part of the brain responsible for determining value.

Activity was highest for 12-item sets, which were perceived as having ‘the right amount’ of options and was lower for 6-item and 24-item sets, which were perceived as ‘too small’ and ‘too large’, respectively.

When subjects were just browsing and didn't have to choose, the decision costs were diminished and the activity patterns vanished.

What does this mean?

As the number of options increases, the potential reward increases, but at the same time, the amount of effort required to evaluate the options increases.

Together, mental effort and the potential reward result in a sweet spot where the reward isn't too low and the effort isn't too high.

This pattern was not seen when the subjects merely browsed the images because there was no potential for reward, and thus less effort was required when evaluating the options.

Final thoughts?

Researcher Camerer points out that 12 isn't some magic number for human decision-making, but rather an artifact of the experimental design. He estimates that the ideal number of options for a person is probably somewhere between 8 and 15, depending on the perceived reward, the difficulty of evaluating the options, and the person's individual characteristics.

He adds that people tend to feel freer and like they have more control over their lives when they have more options to choose from, even if having all those options ends up distressing them at decision time.

Your thoughts?

Any questions or opinions...