Original thinking about how our brains decide

It's Brain Awareness Week and to support its aims of increasing public awareness of the progress and benefits of brain research, we’re highlighting the stellar contribution of three UK neuroscientists.

Pathways of nerve fibres in the brain of a healthy young adult

Credit: Alfred Anwander, MPI-CBS, Wellcome Images

This image, created using tractography, shows pathways of nerve fibres in the brain of a healthy young adult.

Insights into how we make decisions

We make hundreds of decisions every day, from deciding what to wear to life-changing choices. But however big or small the decision, our brain has to consider many complicated factors.

For example, when deciding what to eat as a snack do you choose a healthy option, such as fruit, or an unhealthy option, such as crisps? Multiple factors influence each decision. What are the long-term benefits? What will taste better? What will make me happier? What will make me feel more full?

The brain needs a way of integrating all these factors and deciding on a course of action.

Professors Wolfram Schultz, Peter Dayan and Ray Dolan have spent their careers understanding how the brain does this. In recognition, they have been jointly awarded the prestigious Brain Prize 2017.

Their interdisciplinary work has been pivotal in advancing our understanding of the brain’s reward system, identifying the:

Wolfram Schultz, joint winner of the Brain Prize 2017
Wolfram Schultz
Professor Schultz, a Wellcome Principal Research Fellow, discovered that a small group of cells in the monkey brain, called dopamine neurons, are responsive to rewards, such as fruit juice.

Peter Dayan, joint winner of the Brain Prize 2017
Peter Dayan
Over time, if the monkeys are shown a picture that tells them a reward is coming, these neurons start to signal in anticipation of the reward, rather than when they receive it.

Ray Dolan, joint winner of the 2017 Brain Prize.
Ray Dolan
If the expected reward is withheld, the neurons fall silent at the point that the reward would have been given. The opposite happens when a reward is given unexpectedly: dopamine neurons signal much more actively.

This became known as the 'reward prediction error' and the basis for understanding how we learn.

Professor Dayan's work focuses on building mathematical and computational models of learning and how we choose appropriate actions when faced with rewards and punishments.

He proposed that dopamine neurons are computing the likelihood of actions leading to rewards, and what the likely outcomes will be based on that prediction.

Professor Dolan, a Wellcome Investigator at the Wellcome Trust Centre for Neuroimaging, has been instrumental in furthering our understanding of how human emotion impacts on value learning and decision-making. In doing this, he identified brain circuits that are critical in integrating emotional context into choices.

How brain research advances thinking

The ongoing work of the trio demonstrates that interdisciplinary research can revolutionise our understanding of how the brain works, and how that translates into the real world. 

Their research advances our thinking in a multitude of fields, from economics and social science to psychiatric disorders. Our understanding of addiction to certain drugs or gambling – and why certain people are more likely to become addicted – is in no small part thanks to the insights of Professors Schultz, Dayan and Dolan.

Images credit: Thomas Farnetti, Wellcome