Gambling addiction is a rising concern, but what if the bright lights in the casino are subtly influencing risk-taking decisions?
New research by Flinders University suggests that circadian photoreception, the body's non-visual response to light, could be playing an unexpected role in shaping risky gambling behaviour.
The study published in Nature's Scientific Reports journal examined participants economic decisions using a series of casino scenarios under blue-enriched and blue-depleted light to assess the impact of light wavelengths on risk preferences.
"We found that light with more blue wavelengths in it, which is frequently emitted by LED screens and casino lighting, could subtly influence how people perceive losses and gains," says lead author, Dr Alicia Lander from FHMRI Sleep Health.
"This raises questions about the role of lighting in environments like casinos or online gambling platforms."
The study investigated whether circadia
n photoreception affects risk-taking behaviour during gambling by manipulating the 'melanopic' brightness of light, which targets the body's internal clock, while keeping visual brightness constant.
The results showed that participants exposed to blue-enriched light became less sensitive to losses, making them more likely to choose risky financial options over safer alternatives.
"Typically, people have a strong tendency to avoid losses, often outweighing potential gains in their decision-making," says Dr Lander.
"However, under blue-enriched light, that stimulates non-visual circadian photoreceptors, they demonstrated a reduced sensitivity to financial losses that may influence gambling tendencies, potentially encouraging riskier behaviours.
"Under conditions where the lighting emitted less blue, people tended to feel a $100 loss much more strongly than a $100 gain - the loss just feels worse.
"But under bright, blue-heavy light such as that seen in casino machines, the $100 loss didn't appear to feel as bad, so people were more willing to take the risk."
The study suggests that blue light alters neural processing in brain regions tied to reward and decision-making, such as the amygdala and habenula, possibly dampening negative emotions associated with losses.
"Interestingly, we found that women displayed greater loss aversion than men, showing more reluctance to take risks under both light conditions," says Dr Lander.
"This aligns with previous research indicating that women often experience stronger emotional responses to financial uncertainty, while men may have a greater tolerance for risk."
Modern casinos, gambling machines, and even smartphones use blue-heavy LED displays, and this raises questions about whether lighting could increase risk-taking behaviour in real-world gambling scenarios.
Senior researcher Professor Sean Cain says that as online gambling continues to surge, reducing blue light exposure could be a potential strategy to mitigate impulsive gambling.
"Our study provides new insights into how light influences decision-making in financial risk scenarios and raises important ethical considerations.
"Under light with more blue wavelengths, people may be less able to accurately judge risk and reward due to a decreased cognitive sensitivity to loss," says Professor Cain from FHMRI Sleep Health.
"It is possible that simply dimming the 'blue' in casino lights could help promote safer gambling behaviours."
Researchers acknowledge that while the study used reliable methods and a robust design, the sample size was small (repeated testing in 15 adults) and that more research is needed to explore the relationship between light and risk taking in gambling scenarios.
The article, 'Circadian photoreception influences loss aversion' by Alicia C. Lander, Malisa T. Burge, Brianna G. Thomas, Andrew J. K. Phillips, Elise M. McGlashan & Sean W. Cain has been published in the Nature's Scientific Reports. DOI: 10.1038/s41598-025-97370-z
Acknowledgements: The work conducted was completed with the help of our participants and research staff. This research is funded by the Australian Government through the Australian Research Council (DP210102924, DP220102812) and supported by an Australian Government Research Training Program (RTP) Scholarship.
