A study from biological psychology shows that habitual gamblers use different strategies than controls when it comes to reward learning. This difference could be related to changes in the dopamine system that affect strategic action planning.
Gamblers rely less on exploring new but potentially better strategies and more on proven courses of action that have worked in the past in their pursuit of maximum reward. The neurotransmitter dopamine in the brain could play an important role here. This is what a study from Biological Psychology at the Faculty of Human Sciences conducted by Professor Dr. Jan Peters and Dr. Antonius Wiehler shown. The study was published under the title “Attenuated directed exploration during reinforcement learning in gambling disorder” in the journal Journal of Neuroscience of the Society for Neuroscience.
Gambling disorder affects slightly less than one percent of the population – often men – and is similar to substance use disorders. Scientists suspect that this disorder, like other addiction disorders, is associated with a change in the dopamine system. The brain’s reward system releases the neurotransmitter dopamine while gambling. Since dopamine is important for planning and controlling actions, among other things, this could also have an impact on strategic learning processes.
“One of the reasons why the gambling disorder is of great scientific interest is that it is a dependency disorder that is not associated with a specific substance,” says Professor Dr. Jan Peters, one of the leaders of the study. The psychologists examined how gamblers plan their actions to maximize rewards – how their reinforcement learning works. In the study, the study participants had to weigh up whether they would rather choose already tried or new options in order to gain as much as possible. At the same time, the scientists used functional magnetic resonance imaging to measure the activity in brain regions that are important for processing reward stimuli and for planning action.
Twenty-three regular gamblers and twenty-three control persons (all male) performed a so-called “four-armed bandit task”. The name of this type of decision-making investigation task refers to slot machines, also colloquially known as “one-armed bandit”. In each round, test persons decide between four options (“four-armed bandit”, in this case four colored squares), the winnings of which slowly change. Various strategies can play a role here. For example, you can choose the option that last produced the highest profit. However, you can also choose the option whose profit prospects are the least certain. The gain in information is maximal here.
Both groups won roughly the same amount of money and demonstrated targeted exploration. However, this was significantly less pronounced in the group of gamblers than in the group of control subjects. These results show that while reward learning, gamblers are less likely to adapt to changing environments. At the neural level, gamblers showed changes in a network of brain regions that had been linked to targeted exploration in previous studies.
In an earlier study by the Cologne-based scientists, a pharmacological increase in dopamine levels in healthy volunteers had a very similar effect on behavior. “Although this suggests that dopamine could also play a role in the reduction in targeted exploration in gamblers, this relationship still needs to be investigated directly in future studies,” explains Dr. Antonius Wiehler.
Further research must also clarify whether the observed changes in decision-making behavior among gamblers are a risk factor for or a consequence of regular gambling.
Reference: A. Wiehler, K. Chakroun and J. Peters, “Attenuated Directed Exploration during Reinforcement Learning in Gambling Disorder”, Journal of Neuroscience 17 March 2021, 41 (11) 2512-2522; DOI: https://doi.org/10.1523/JNEUROSCI.1607-20.2021
Provided by University of Cologne