“We are trying to find the root of compulsivity in the brain”

“Compulsive behaviors come in many shapes and are at the core of several psychiatric disorders. We are trying to find the common root of compulsivity in the brain”

The world of neuroscientist and psychologist Ingo Willuhn revolves around the neurotransmitter dopamine. He states: “I am fascinated by the question of how much conscious control of our behavior we really have. How does voluntary behavior turn into habits and in some instances into pathological, maladaptive habits?”

Dopamine gives us motivational drive and helps to establish habits. Ingo thinks that when dopamine malfunctions conditions such as drug addiction and obsessive-compulsive disorder develop. Such compulsive disorders are characterized by a common urge to act without being able to stop. “You know that feeling when you really intend not to do something, but you do it anyway?”

Checking our emails or enjoying a glass of wine after coming home from work are intended actions with a purpose. We usually do not perform them when internet access is not available or if we had alcohol prior to coming home. However, when the above actions are repeated many, many times, they can become automatic. “In principle, forming habits is a great thing. For example, it is the only way we can drive a car without having to think about every single movement. But sometimes the automatic nature of habits becomes problematic: When they cause harm and persist against our will.” Such a lack of flexibility is at the core of mental disorders such as addictions (internet, gambling, or drugs) and obsessive-compulsive disorder.

“We want to know how free will is switched off in the brain”

Ingo’s group specializes in investigating the basal ganglia, a brain system common to all mammals that contains the highest concentration of dopamine in the brain. The basal ganglia are thought to select behavior appropriate for a given situation and turn it into automatic sequences of actions. “We watch the brain work the exact same moment our mice and rats are acting in behavioral tasks that test motivation and cognition. The same moment they are forming habits.” The team uses a variety of innovative technologies to look into the brain, including sensors that can measure millisecond changes in brain chemistry and physiology. They also actively alter brain function by introducing artificial receptors into the brain that can only be activated by the experimenter. “We want to identify the switch in the brain that makes behavior automatic. In a more provocative way you could say, we want to know how free will is switched off in the brain,” Ingo states. The experiments on mice and rats are aimed at improving the treatment of patients suffering from such compulsivity in the long run and hopefully eventually “flipping the switch back”. Ingo pursues this goal together with Prof. Damiaan Denys, the chair of the Amsterdam UMC Psychiatry department, whose team of clinicians studies and treats patients suffering from compulsive disorders.