While growing up in West Germany in the 1950s, Wolfram Schultz had little interest in science — or in school. “I was not a good student in high school,” he recalls. “Mathematics was easy, and the rest was boring.” After a two-year stint in the military, Schultz toyed with the idea of going into engineering — or, perhaps, even into the diplomatic service. After enrolling in the University of Hamburg in 1966, however, Schultz decided, to pursue a medical degree, in large part because it would enable him to do biology research, a field that had begun to interest him. “At that time, biology was a very, very niche field with hardly any job prospects,” he says. “Many people who were interested in it would do medicine.”
Schultz received his MD from the University of Heidelberg in 1972. He then went on to complete three postdoctoral research fellowships. The first was with the German neurophysiologist Otto Cruetzfeld at the Max-Planck Institute for Biophysical Chemistry in Gottingen, Germany; the second, with the Australian neurophysiologist John C. Eccles at State University of New York at Buffalo in the United States; and the third, with the neuropsychopharmacist Urban Ungerstedt at the Karolinska Institute in Stockholm. Schultz says he enjoyed being a “wandering scientist.” “I didn’t want to do what everybody else was doing,” he recalls.
In 1977, Schultz moved into a junior faculty position at the University of Fribourg Switzerland, where he completed his “habilitation” (an advanced PhD) in physiology and launched his own research laboratory. “Because I had a medical background, I wanted to do something that had a relationship with what goes wrong in the human brain,” he says. Schultz decided to work on dopamine neurons because of the role their deficiency plays in Parkinson’s disease. “We found some movement-related activity that might explain Parkinson’s disorder, but it was not very satisfying,” he recalls. “But we kept looking at what was happening, and refined our behavioral tests.”
That tenacity eventually revolutionized the concept of how reward information is processed in the brain. In a series of experiments conducted with macaque monkeys beginning in the 1980s and 1990s, Schultz demonstrated that when the animals received a reward (fruit juice), the activity of dopamine neurons in a brain area known as the basal ganglia increased, causing the cells to release the neurotransmitter. He also showed that this neural pattern changes as the animal learns how to respond to receive the reward — and that learned cues could trigger changes even in the absence of a reward.
“At first, we couldn’t believe this dopamine signal,” Schultz recalls. “We thought we were making a mistake. That’s why we went on to look at other areas of the brain.” Soon, Schultz and his team had located reward-response neurons in additional brain structures, including the orbitofrontal cortex and the striatum. In two seminal papers published in Science and the Journal of Neurophysiology in 1997 and 1998 (the second one written, he says, during long train journeys from his home in Switzerland to his mother’s home in Germany), Schultz described what those findings meant — that the theoretical and psychological concept of reward can be directly linked to a signal carried by dopamine neurons in the brain. One of the figures in these papers, which shows dopamine neurons signaling reward prediction error (the difference between a reward that is being received and the reward that is predicted to be received), has become iconic in behavioral neuroscience.
Schultz’s groundbreaking discovery — that dopamine neurons signal errors in reward prediction — quickly changed how scientists study learning in the brain, and the link he made between theory and experiment now influences almost all research on reward and choice. As Schultz explains, this biological reward process is what drives people to want high-calorie foods, or a bigger house, or a promotion at work. And although the process is essential for keeping us alive, it can also go awry, leading to drug abuse, gambling and other addictions. The dopamine neurons, explains Schultz, can act like “little devils in our brain,” urging us to anticipate and seek out the next reward.
In 2001, Schultz moved his laboratory to the University of Cambridge in the United Kingdom, where he became a Wellcome Principal Research Fellow and Professor of Neuroscience. In the ensuing years, much of his research has focused on uniting the prediction error concept from animal learning theory with economic utility theory (the belief that the utility, or subjective value, of an item is a measure of the satisfaction that the consumer will derive from the consumption of it). In a string of experiments with his gifted collaborators, Schultz has found strong evidence suggesting that the dopamine response is related to the concept of utility — findings that are transforming both experimental and theoretical research in the relatively new field of neuroeconomics.
Schultz has received numerous honors and awards for his work. He is a Fellow of the Royal Society and past president of the European Brain and Behaviour Society. Schultz lives in Cambridge with his wife, Gerda. They have three grown children, Johannes, Thomas, and Carolina.