insula gambler's fallacy

A new study shows that the insula may be the key to understanding the psychology of gambling. (Image:

One of the great things about being human is having a brain that’s magnificent at finding patterns. This helps us hundreds of times every day, but it can also be a curse: we’re also very good at finding patterns that don’t exist at all. This leads to occasional problems like the so-called “gambler’s fallacy,” which is the idea that we can be due to win in a game that’s completely random.

This is all old news, of course. But scientists at the University of Cambridge have found that a very specific part of the brain might be responsible for allowing people to fall victim to this fallacy. It might also be the area of our brains that lead some to fall prey to gambling addiction.

The area in question is the insula, a portion of the cerebral cortex found in both hemispheres of our brain. The research scientists say that an overactive insula can cause people to chase losses.

“Future treatments for gambling addiction could seek to reduce this hyperactivity, either by drugs or psychological techniques like mindfulness therapies,” the researchers said.

Study Used Slots, Roulette Games

This conclusion was based on research that studied people as they played computerized versions of slot machines and roulette games.

These studies confirmed the results of many before them. In the roulette game, players were simply asked to pick red or black. Most players had a tendency to pick whatever color had been coming up recently – a phenomena sometimes known as the “reverse gambler’s fallacy,” in which a player assumes a certain bet or machine is “hot” even though the results are completely random.

Similar results were found in the slot machine trials. Players spun the reels and could achieve a win or a near-miss, in which they were just one symbol away from a jackpot. In most cases, these near-misses tended to encourage the gamblers to keep playing.

These two patterns were common in subjects with healthy brains. Researchers also had a variety of subjects with injuries to specific parts of the brain play the games to see how they would react – a common way of testing how the brain processes information.

“While neuroimaging studies can tell us a great deal about the brain’s response to complex events, it’s only by studying patients with brain injury that we can see if a brain region is actually needed to perform a given task,” said Dr. Luke Clark of the University of Cambridge, leader of the study.

Subjects with Injured Insula React Differently

The results shined light on what might be going on in the minds of gamblers. Nearly all of the subjects with brain injuries or damage showed the same tendencies as those with healthy brains. But there was one exception: the patients with damage to their insula did not look at the games the same way. They tended to stick with one color no matter what in roulette, and treated near-misses like any other loss on the slot machine.

This suggests that the insula may be crucial to the psychological issues involved in gambling. The insula is already known to be involved in the decision-making process and “gut feelings.”

The findings were published in Proceedings of the National Academy of Sciences.