When pathological gamblers come extremely close to winning a game — but not quite — it strongly activates a reward-related area of the brain, leading them to believe they are “almost there” and further reinforcing the gambling addiction, according to a new study by Dutch neuroscientists.
For the study, researchers compared the fMRI scans of 22 pathological gamblers to a similar number of healthy adults. The scans had been taken while the participants were playing a slot machine game.
Despite being objective losses, near-misses activated a particular reward-related area in the brain’s striatum in the participants, and according to the new findings, this activity was exaggerated in pathological gamblers. Researchers believe this phenomenon reinforces gambling behavior by creating an illusion of control over the game.
“We’ve made our gambling game as lifelike as possible by improving the visuals, adding more sounds and adapting the speed of the slot wheel compared to previous versions,” said neuroscientist Guillaume Sescousse from the Donders Institute at Radboud University in the Netherlands.
“In our game, the chance for a near-miss was 33 percent, compared to 17 percent for a win and 50 percent for a complete miss.”
So why does almost winning trigger such a strong feeling of reward in the brains of pathological gamblers?
“In normal situations near-miss events signal the fact that you are learning: This time you didn’t get it quite yet, but keep practicing and you will,” said Sescousse.
“Near-misses thus reinforce your behavior, which happens by triggering activity in reward-related brain regions like the striatum. This also happens when gambling. But slot machines are random, in contrast to everyday life, which makes them such a great challenge to our brain. That’s why these near-misses may create an illusion of control.”
Furthermore, gamblers have a strong illusion of control and tend to trust in luck more than the general population.
Previous animal studies have shown that behavioral responses to near‐miss events are regulated by dopamine, but this dopaminergic influence had not yet been tested in humans. Therefore, all participants in the current study performed the experiment twice: once after receiving a dopamine blocker, and then again after receiving a placebo.
Surprisingly, brain responses to near-miss events were not influenced by this manipulation. “For me, this is another confirmation of the complexity of the puzzle that we are working on,” Sescousse said.
The study is published in the journal Neuropsychopharmacology.