How our brain makes decisions

Whether it's chocolate to relieve frustration, wine after a stressful day at work, scrolling on your smartphone to relieve boredom or reaching the next level in a computer game - all of these are triggers that activate our reward system and weaken our sense of control. Why we choose substances or actions even though we know that they are not good for us in the long term or are even addictive is one of the many questions that Professor Alexander Soutschek deals with.

The 42-year-old psychologist has held a Heisenberg Professorship for "Neuroscience of Decision Making" since March 2026. The professorship, which is funded by the German Research Foundation, is based at the Department of Psychiatry, Psychosomatics and Psychotherapy at the University Hospital of Würzburg.

Impulse control, metacognition and mental effort

"Decision-making processes are severely impaired in almost all mental illnesses, especially in addiction disorders and psychoses. Professor Soutschek's research will therefore significantly strengthen the profile of neuroscience in our Department of Psychiatry, Psychosomatics and Psychotherapy. We are extremely pleased that we have been able to recruit him for Würzburg," comments Clinic Director Sebastian Walther.

Soutschek specialises in impulsive decisions. How can we control our impulses? Especially when we have to weigh up different options, such as "I want this right now" and "This is better for me in the long term". In addition to impulse control, which is crucial in addictive behaviour, Soutschek is interested in metacognition - the ability to assess one's own thoughts and performance - and the phenomenon of mental effort, which plays a role in ADHD, for example.

How does our brain control motivation? Why do we sometimes find it difficult to concentrate or make an effort? "This is also a decision-making process," says Alexander Soutschek. "People with ADHD, for example, are less likely to decide to make a mental effort to achieve a goal. This is because it tires them out more quickly to maintain attention."

Stimulating brain areas and guiding decisions

In order to understand and influence the decision-making processes in the brain, he uses various neuroscientific methods such as neuroimaging, computer-aided modelling of human behaviour, psychopharmacology and brain stimulation, i.e. gentle methods to specifically influence certain areas of the brain.

"If we see that stimulating a specific brain region can help our patient groups, then we naturally want to prove the success in a clinical trial and compare the intervention with other treatments," says Alexander Soutschek. He tests every brain stimulation on himself beforehand so that he knows what he can expect from others. As a rule, you don't feel the stimulation, but it can be unpleasant in some places.

Which brain region is responsible for making decisions? "As there are different types of decisions, different brain mechanisms also play a role," explains Alexander Soutschek. There is therefore no decision-making centre, but rather a network of several areas. The prefrontal cortex, for example, collects information and analyses options and goals. The striatum, in turn, is the main entrance to the deeper basal ganglia and integrates motivation and reward. After feedback to the cortex, the decision is implemented or adjusted. Emotional information from the limbic system modulates this process.

Addiction pulls and ADHD slows

In the case of addiction, for example, the limbic-striatal reward system is overly active for action options associated with the addiction. At the same time, the area of the brain responsible for self-control and long-term thinking is weakened. This imbalance means that short-term rewards are overvalued while negative consequences are ignored. Decisions are then more impulsive and stimulus-driven.

In ADHD, the control and monitoring function in the forebrain is less efficient. This makes it difficult to slow down impulses, wait and see or keep long-term goals in view. Here, too, there is a preference for immediate rewards, although this is less due to overexcitation, as occurs in addiction, and more due to an unstable regulation of attention and motivation.

Philosopher and psychologist from Munich

Alexander Soutschek was born in Munich in 1983. He studied philosophy and psychology and gained a doctorate in both subjects. In psychology, he researched the interplay between cognitive control and motivational evaluation processes, which together determine whether and how attention and actions are focussed on a goal. In philosophy, he investigated whether Descartes' classical philosophical theory of knowledge could be replaced by empirical sciences such as psychology.

His conclusion: "Psychology is good at explaining how people actually acquire knowledge and what cognitive processes take place. However, it cannot answer what knowledge actually is or when it is justified. Nor can it answer all the questions posed by philosophical sceptics. Naturalistic epistemology therefore usefully complements philosophy, but does not replace it."

After completing his doctorate, Alexander Soutschek worked for a year and a half as a postdoc at the Institute of Psychology at Humboldt-Universität zu Berlin and then for almost five years at the University of Zurich. In 2019, he was awarded a DFG-funded Emmy Noether Group for Neurocognitive Psychology at Ludwig-Maximilians-Universität München. He has now successfully applied for a Heisenberg Professorship, which he was able to establish in Würzburg - his preferred location.

Neuroscientific expertise in Würzburg

This is because the combined neuroscientific expertise at the Würzburg Centre for Mental Health (ZEP) offers numerous starting points for his research. Grit Hein, Head of Translational Neuroscience, is investigating, for example, how the social modulation of learning and decision-making processes affects health. Lorenz Deserno heads the "Cognitive Neuroscience in Developmental Psychiatry" working group and is researching decision-making processes in children and adolescents with ADHD, among other things.

And the use of transcranial brain stimulation (TMS) is one of the central research focuses of the ZEP. Martin Herrman, head of the "Functional Imaging and Non-invasive Brain Stimulation" working group, is investigating, for example, how the fear of spiders can be eradicated from the brain using TMS. Sebastian Walther is researching TMS as a new therapeutic approach for motor disorders and communication problems in mental illnesses. The clinic has participated in multi-centre studies on TMS for depression and hallucinations.