During adolescence, the brain undergoes a fundamental reorganisation. It is a time when many mental illnesses can first emerge, but it’s unclear how this happens. Tobias Hauser explains that harnessing the power of citizen science through games could be key to understanding this developmental period.

Juanita Bawagan: Decision-making is behind every move we make and all our major life choices. What happens in our brains when we make decisions?

Tobias Hauser: As we move through the world, millions of pieces of information enter our brain through our eyes, ears and other sensory organs. What happens between these inputs and our actual behaviour, when we make decisions, ranges from very simple to extremely complex.

The simplest decisions are those we don’t even think about. If a snake lunges at you, you’ll jump back. While this is still a decision, it’s really more of a reflex. At the other end of the scale, questions such as ‘what do I want to study?’ have many long-term consequences and should be considered very carefully. Researchers think that the prefrontal cortex is responsible for complex decisions that require really thinking about what could happen in the future, in order to make a good choice – although what each person considers good is very subjective and changes over time.

“We know that teenagers are bigger risk takers, more susceptible to peer influence and less likely to follow advice than adults, but what we don’t fully understand is what could be driving these behaviours.”

JB: Why are you particularly interested in adolescent decision-making?

TH: Adolescence is a very important, but often misunderstood period. We know that teenagers are bigger risk takers, more susceptible to peer influence and less likely to follow advice than adults, but what we don’t fully understand is what could be driving these behaviours.

For example, teenagers are often stereotyped as stubborn or disrespectful when they ignore advice from adults. In a recent study, we found that teenagers were less likely to follow advice than younger children, but also that they were much more aware of their thought processes and performance. This suggests that they can recognise bad advice and realise that if they are confident in their own decision, they should stick to it. What has typically been seen as a blatant disregard for guidance may in fact be evidence of the emergence of good and independent decision-making.

JB: You’ve just launched Brain Explorer. Why did you choose to create a gaming app to understand the brain?

TH: Brain Explorer, like all my research, is driven by a desire to understand why and how mental health problems arise. The majority of psychiatric disorders emerge before early adulthood, and adolescence is a period in which the brain undergoes a fundamental reorganisation. If the brain doesn’t develop as it should, that can lead to mental health problems. But there is very little data that ties this all together.

Brain Explorer aims to fill this gap. In the app, you’re an astronaut travelling through the galaxy solving puzzles and answering questions about yourself along the way. The games are fun, but also linked to our brain research. The data that people share anonymously helps us gain a better understanding of decision-making and how it may be linked to mental illnesses.

JB: How have games previously helped in the quest to better understand the brain?

TH: Neuroscientists are beginning to recognise the potential of citizen science to generate really big data. Sea Hero Quest and The Great Brain Experiment are great examples of how small-scale studies can be translated into games and apps that crowdsource data. Instead of examining 20 to 40 subjects in brain scanners, researchers can potentially look at data from tens of thousands of people playing games around the world. This allows researchers to study decision-making on a whole different scale and in much more detail.

My research brings together the fields of psychiatry, neuroscience and computer science to understand the adolescent brain. By combining citizen science and our interdisciplinary methods, we can develop computational models to look at different bits of the decision-making process and see how they vary between people with different symptoms and across ages.

“As with all chronic illnesses, the emphasis in mental health should be on prevention as well as treatment, so we need to act early and effectively.”

JB: How could this research help people in the future?

TH: As with all chronic illnesses, the emphasis in mental health should be on prevention as well as treatment, so we need to act early and effectively. This research could help develop predictors that tell us whether someone might develop obsessive-compulsive disorder (OCD), for example. We might then be able to intervene early to try to prevent the development of such disorders. A better understanding of the mechanisms of the brain will also allow us to develop more targeted ways of treating patients with mental illnesses.

Adolescent mental health has been neglected for decades. Most of the relevant studies have been conducted in adults, although we know that most mental illnesses emerge in adolescence. But now the wider public is starting to recognise that mental health matters in adolescents and that there is an urgent need to address this issue.

The COVID-19 pandemic has further highlighted this urgency. Adolescence is usually a highly social time when a person’s personality and brain are developing. Being cut off from peers could have a huge mental health impact, not to mention the long-term effects of uncertainty and disrupted education.


Tobias Hauser is the creator of Brain Explorer, a gaming app to help understand the brain. You can download the app and play the games on Apple and Android devices.

He is a Principal Research Fellow at the Max Planck UCL Centre for Computational Psychiatry and Ageing Research and at the Wellcome Centre for Human Neuroimaging. He is interested in the neurocomputational processes underlying learning and decision-making, and how these go awry in developmental psychiatric disorders.

Hauser and his Developmental Computational Psychiatry Group investigate how cognitive biases in obsessive-compulsive disorder (OCD) can help us better understand the neurocomputational mechanisms underlying this disorder. His primary focus is on the influence of neurocognitive development on the emergence of psychiatric disorders during adolescence. In his work, he combines neuroimaging, pharmacology, and computational modelling in youths and adults with and without mental health problems.

Hauser has received several prestigious prizes in psychiatry, such as the Emerging Leaders Prize in Adolescent Mental Health (2018) and the Kramer-Pollnow Award (2017). His work is supported by Wellcome, the European Research Council, the Royal Society, the Medical Research Foundation, the Jacobs Foundation, the Brain & Behavior Research Foundation and the Max Planck Society.

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