When the researchers stimulate the frontal cortex with a magnetic coil, their test subjects can think faster and empathise better with others. | Photo: Markus Bertschi

The basement of the Zurich University Hospital is a labyrinth of long, sterile corridors. A whiff of disinfectant hangs in the air. The high door before us with the oak veneer seems out of place. When you open it, you find yourself in a laboratory that looks like an alpine hotel – though without the grandiose view. “We want to study social behaviour here. So you can’t just stick people in a dark basement”, says Christian Ruff to explain his lab’s interior elegance.

Ruff is a professor of neuroeconomics and decision neuroscience at the University of Zurich and the director of its Laboratory for Social and Neural Systems Research (SNS Lab), founded in 2007. Its mission is to peer into the mind of society. “We want to understand how people tick so that we can begin to comprehend our decisions and society as a whole”, says Ruff. This is called behavioural economics.

“For decades now, we’ve been making assumptions about society that might not even be true”, says Ruff. For example: we assume that if the state tolerates tax evasion, then the number of tax evaders will automatically rise. After all, why should anyone be honest if they don’t need to be? But no one knows right now if this is really how our brains work. “That’s why we want to explore the brain processes that are responsible for our actions. We want to get hard facts and provide a clear vocabulary. This might also let us find out how politicians, organisations and authorities can encourage people to behave differently”.

Watching the brain make decisions: In the Laboratory for Social and Neural Systems Research, brain waves are measured in real time using EEG. | Photo: Markus Bertschi

The centrepiece of the lab is its magnetic resonance imaging system (MRI). The test subject plays a decision-making game while the researchers observe their brain activity. | Photo: Markus Bertschi

Christian Ruff (left) is a neuroeconomist. Together with SNS Lab Manager Marius Moisa, he identifies patterns in our social thinking. | Photo: Markus Bertschi

Three beats two, two beats one, one beats three – just like rock, paper, scissors. The test subjects have to develop strategies for winning. | Photo: Markus Bertschi

The test subjects play better when they can ‘read’ their opponent and can identify their playing strategy. | Photo: Markus Bertschi

If you’re going to study social behaviour systematically, you need a social action. Something simple that can be repeated as often as you want. In the experiment scheduled for this morning, the choice is rather surprising: it’s the game rock, paper, scissors. The experiment is being run by the postdoc Gökhan Aydogan. He’s just prepared a new round of the game for six young women and men who are each seated in front of their own screen.

The test subjects are mostly students in Zurich. “Now please press the letter S, everyone”, says Aydogan. Instead of the terms ‘scissors’, ‘rock’ and ‘paper’, the game uses the numbers one, two and three. Three beats two, two beats one and one beats three. “You can start playing now”.

Predicting who’s good at reading others

Isn’t this a bit childish? “No”, says Aydogan. “It’s actually very astute, because this game requires many special abilities of our mind. Most people follow a specific strategy or certain habits. For example, someone might have a preference for the number one. Another will mostly play the number with which they won the last time. Or always pick a number higher than their opponent did”.

What’s important is that the participants have to put themselves in their opponent’s shoes if they want to win. “They have to understand how the other person ticks. It’s a fundamental skill that we need all the time in society”, says Aydogan. “In relationships, for example, but also in politics, at school or in negotiations”. People who cannot ‘read’ others will lose more often. There is a spectrum to be observed here, ranging from those who are excellent at analysing others to those who are quite unable to do so. The way the experiment is set up allows this spectrum to be created artificially.

A magnetic coil is now placed on the head of each test subject that emits electromagnetic waves at a specific frequency. Depending on where it’s positioned on the skull, it can stimulate different areas of the brain during the game – such as the frontal cortex, which is responsible for logical and analytical thinking. “When we stimulate the frontal cortex, people can think faster and empathise better with others”, says Marius Moisa. He’s the SNS Lab Manager and is responsible for technical supervision. “They then win more often”. In other words, they acquire social ‘super brains’. But it also works the other way round. If the stimulation is provided in a different rhythm, the area of the brain being targeted becomes tired. “Those test subjects suddenly find it harder to read their opponents, and so they lose”, says Moisa.

Visualising active regions of the brain

No matter how many times the participants play with a magnetic coil on their heads, one thing is always lacking: a direct view into their brain. This is where the centrepiece of the laboratory comes into play: a brand-new magnetic resonance imaging system (MRI) that was only installed here in early 2025. “We had to knock down a few walls to fit it in”, says Ruff. Its control centre is in the next room, from where a glass window affords Ruff a direct view of the scanner.

A young woman is currently lying on the patient table and is being rolled head-first into the tube. A few moments later, colourful images of her brain, taken from the front and side, appear on the screens in the control room. Another screen has also been installed directly in front of the test subject’s face so that she can continue participating in the game, operating a cursor on the screen with one hand. “The scanner measures in real time the oxygen needed by different areas of the brain. This enables us to see which parts of her brain are active when she makes decisions”, says Ruff.

These images are then evaluated statistically. Today, the researchers have already collected so much data that they can identify a pattern. “We’ve acquired a kind of fingerprint of social thinking”, says Ruff. He now knows which areas are active when someone puts themself in someone else’s shoes. “This activity pattern even allows us to predict how well a person will perform in the game”. Their success rate is an impressive 80 percent. In future, Ruff would like to use this art of prediction to identify learning disorders or autism in children, for example.

Another potential area of application is researching into stress. The SNS Lab is currently in contact with various research networks in Switzerland and around the world. “At some point, we’d like to be able to use a brain scan to measure a person’s resilience to stress directly. Before they’ve finalised their career choices, they could find out whether they’re actually suited to being a firefighter or a policeman”.

The EEG cap is one of the lab’s most important features for investigating social and neuronal systems. | Photo: Markus Bertschi

The MRI scans of the test subjects help complete the researchers’ understanding of brain processes. | Photo: Markus Bertschi

The magnetic coils stimulate different brain areas during a game. They alternately help or hinder participants to understand what makes their opponent tick. | Photo: Markus Bertschi

The test subject is instructed in how to use the cursor during an MRI. | Photo: Markus Bertschi

Stimulating the brain with a magnetic coil can alter the social thinking of a test subject. | Photo: Markus Bertschi

Personal effects are stored safely in lockers during the experiments. | Photo: Markus Bertschi

But their research isn’t that far yet. “First, we need to understand how our brain functions under stress. Do certain things work better, or do we develop what’s notoriously called ‘tunnel vision’ and lose the ability to think clearly?”

In order to expose their test subjects to stress in the scanner, the researchers resort to a simple trick: maths. The woman having the MRI is now presented with a series of long maths problems: what’s seven times nine? Then divide the result by three, and take away four. She moves the cursor to 17 – she just made it! Because the next problem appears after three seconds. After just a few minutes of this, anyone will feel as if they’ve spent the whole day with a nagging boss breathing down their neck to make them get through a stack of paperwork before midnight. Now that our test subject has completed her conditioning, she’s sent back to rock, paper, scissors.

Getting a better understanding of corruption

It doesn’t matter how high the resolution is of the MRI images: they are still never fast enough for the human brain and always appear with a delay of a few seconds. “We can get good measurements of where activity occurs in the brain during the decision-making process, but our method isn’t very accurate in terms of timing”, says Ruff. This is where the SNS Lab’s third important component comes into play: electroencephalography (EEG). This measures brain waves in real time and is accurate down to the millisecond.

To this end, our test subject sits in an adjoining room with a cap placed on her head that’s studded with electrodes. The thickness of the skull means that the measurements acquired are rather poor when it comes to spatial resolution, but when combined with the MRI images they can still provide a very accurate picture of what’s happening in the brain.

“Our research can help make social processes more efficient”, says Ruff with conviction. Apart from helping with career choices, it might also be able to improve ethical behaviour in areas such as consumption, environmental pollution and corruption. “Then there’s the pathological dimension. Depression, anxiety and borderline personality disorders: all these labels are much too vague”, says Ruff.

Here, too, we need to understand the fundamental brain mechanisms. “We hope that we might then be able to provide effective therapies and improve the lives of those who’re affected”. For this, Ruff’s hospital basement with its hotel ambiance and state-of-the-art technology has already taken a step in the right direction.