A recent study provides fresh insight into gambling addiction. According to the findings, the sounds and lights that accompany a win on slot machines increase the likelihood of making risky decisions.

An addiction to gambling affects a significant proportion of adults in the United States.

The North American Foundation for Gambling Addiction Help estimate that 2.6% of US adults are addicted to gambling, which equates to around 10 million people.

The cost to the economy is equally shocking, with experts estimating it to be close to $6 billion per year.

As with an addiction to alcohol or another drug, treating a gambling addiction can be a challenging and lengthy process.

Understanding exactly why and how certain individuals become addicted to gambling might help scientists find new ways to minimize the risk of becoming hooked.

With this purpose in mind, researchers are keen to understand why the experience of gambling machines is such a strong lure for some people.

'Bells and whistles'

Earlier studies in rodents have shown that linking audiovisual cues to rewards can alter behavior. For instance, in one study, scientists paired food rewards with lights and sounds in a "rodent gambling task."

During the task, the rats chose between four options that had different levels of risk and reward. The most sensible approach for the rodents was to choose the option with the smallest reward but the least severe penalty rather than the high-risk, high-reward options.

For some of the rats, the researchers paired sounds and lights with the rewards. The study showed that the rodents in this experimental group were more prone to making riskier choices.

To date, research has not investigated this effect in humans. Recently, researchers led by Catharine Winstanley and Mariya Cherkasova—both from the University of British Columbia in Vancouver, Canada—designed an experiment to fill this knowledge gap. The Journal of Neuroscience published their results.

The power of lights and sounds

The new experiment used the Iowa Gambling Task (IGT), which is similar to the rodent gambling task that is outlined above. The design of the IGT means that it simulates real-life decision-making. They followed this with a two-choice lottery task.

Some of the participants experienced auditory and visual cues whenever they won. These cues replicated the "bells and whistles" that accompany winning on commercial gambling machines.

The results showed that participants who had exposure to these types of sights and sounds during the two-choice lottery task were more likely to make high-risk decisions. In particular, linking larger wins with images of stacks of money and extended casino jingles boosted risky choices.

Overall, the authors conclude:

"Our data directly demonstrate for the first time that reward-concurrent sensory cues can promote risky choice in human subjects."

They continue, "To our knowledge, this is the first direct demonstration of [the] risk-promoting effects of such cues in human subjects."

The eyes have it

The scientists also measured changes in the size of the participants' pupils and charted their eye movements.

Changes in pupil size demonstrated that participants were more aroused when lights and sounds accompanied their win. The results also identified a link between riskier decisions and pupil dilation, which, according to the authors, is the first demonstration of this effect.

Interestingly, the audiovisual cues blunted the participants' ability to take in information about the odds of winning. For instance, those playing the game with audiovisual cues spent less time looking at the probability information on the screens.

The authors believe that their "findings lend support to the notion that sensory stimulation in gambling could act to de-emphasize the unfavorable odds of winning."

On the whole, the results seem to show that the lights and noises that gambling machines produce increase the pleasure of winning, dampen a player's ability to understand the risks, and increase the likelihood of them taking more risks.

It is important to add that this is the first trial of its type in humans, and it included just 131 participants. The results are fascinating, but additional studies will need to replicate them to solidify the conclusions.