Patterns in the brain reveal our fear of the unknown

Research is under way into brain patterns that reveal how we learn social threats, fears and values. This knowledge may give us new tools to cope with everything from xenophobia to anxiety conditions.

Andreas Olsson

PhD in Psychology

Wallenberg Academy Fellow 2014

Karolinska Institutet

Research field:
Understanding the mechanisms behind aversive learning and other emotional processes in social situations.

As a Wallenberg Academy Fellow, Andreas Olsson will be finding out more about what happens in the brain when fears and values are learnt. We already know for certain that our commonest phobias and fears are linked to the conditions under which early humans lived.

“Many people are scared and wary of heights, crowds and strangers. These behaviors are often rooted in primitive mechanisms that have evolved in response to critical problems faced by our ancestors,” Dr. Olsson explains.

Ancient instincts cause problems

But instincts that were once necessary may be a handicap in modern life. In stressful situations a person may become paralyzed with fear – increasing the risk of accidents. For some people, an inability to cope with fear may cause anxiety disorders and depression. It is also likely that evolution has prepared humans to develop persistent fear of individuals who belong to other “tribes”, fomenting xenophobia and conflict.

The brain has not kept up with developments, as Dr. Olsson says:

“Fear that was an adaptation to our original environment becomes dysfunctional in modern life.”

“Us” and “Them” in the brain

Dr. Olsson and his colleagues are mapping patterns in the brain that reveal how fears and values are learnt and change. There are different ways of learning, depending on factors such as our own expectations and whether we learn directly through our own experiences or indirectly via information we receive from others.

Among other things, the experiments have shown there are automatic processes in the brain favoring an “Us” and “Them” approach. One study paired images of faces belonging to the own and another ethnic group with an aversive experience. Following such aversive experiences, fair-skinned people tended to be more afraid of people with darker skin. Conversely, dark-skinned people tended to be afraid of those with lighter skin. But even seemingly arbitrary distinctions drawn in the laboratory, based, for example, on T-shirt color, give similar results.

“Throughout the world there are conflicts based on group affiliations, such as ethnicity, religion or the football clubs people support. We are studying the factors common to these social values in order to learn more about the underlying mechanisms,” Olsson explains.

U.S. models

In the experiments the researchers have volunteers react to various stimuli, while simultaneously measuring their eye movements and brain activity. Using functional magnetic resonance imaging (fMRI) they are able to see in real time how the brain works by measuring blood flow, thereby linking a given activity to a specific part of the brain. Using knowledge drawn from animal models it is then possible to conduct more detailed investigations of various regions of the brain, such as the amygdala, which plays a primary role in emotional reactions.

Most of the research is being conducted at the researchers’ own laboratory: the Emotion Lab at Karolinska Institutet in Solna, north of Stockholm. Their research is modeled on pre-eminent research environments in the U.S., including New York University and Columbia University, where Dr. Olsson researched as a doctoral student and postdoc.

Expression of fear may create phobias

One line of research concerns transference of fears and values – how we learn from others by watching and listening to them. Earlier studies have shown that monkeys born in captivity, without any experience of snakes, can nonetheless develop a lifelong fear of snakes merely by observing another monkey exhibiting fear of a snake on a single occasion – a phenomenon known as “one-shot learning”.

Humans have the same mechanisms. An expression of fear in another person can be transferred and develop into a phobia. Here too, Olsson’s research reveals a divide between individuals within a group and those belonging to another group.

In one experiment about fifty fair-skinned subjects were asked to watch actors – here called demonstrators – who were given unpleasant electric shocks when they saw a picture of a snake. The subjects found it easier to associate the picture of a snake with pain when the demonstrators were also fair-skinned.

And when the experiment shifted to learning that the snake picture was no longer coupled to an electric shock, the subjects found it easier to conquer their fear of snakes if the demonstrators expressing calm and reassurance belonged to their own ethnic group.

“We don’t know for sure why this is so, but one interpretation is that a sense of belonging and trust is decisive when we learn from others that something that was previously unpleasant is now harmless.”

“The funding means I can continue researching into the subjects I really care about in a ‘high-risk, high-gain’ research project that is dependent on long-term funding. Now we can delve deeper into the subject on a broader front, and study more realistic social situations with the help of new experimental models.”

Driven by curiosity about people

Dr. Olsson has been interested in people since his teens. It was then he became interested in philosophy, later followed by biology.

“I’m driven by an abiding curiosity in how people work. One of my dreams is to understand the mechanisms by which social values are shaped and changed. Many of the aversions or fears we have are functional, so we should definitely not eradicate them. But hopefully, our research will pave the way for a better understanding of how we can approach autism and anxiety disorders, for example, and also give us better tools for combating antisocial norms and reinforcing pro-social ones.”

Text Nils Johan Tjärnlund
Translation Maxwell Arding
Photo Magnus Bergström