If you're trying to curb a gambling habit, then you should stay away from casinos when you're moderately tired. It will be easier to pass by the blackjack tables, emerging research suggests, when you're either wide awake or exhausted. Why? Well, when you're just a little bit tired, you're low enough on self-control, but still have the oomph you need, to follow through on risky urges.
Severe sleep loss has been associated with risky behavior, such as drug use, unsafe sex and doing the cinnamon challenge. This phenomenon is thought to be rooted, at least partially, in two brain changes: 1) increased activity in the amygdala, a tiny almond-shaped structure that fires up in response to emotionally arousing cues in the environment, and 2) reduced connectivity between the amygdala and the prefrontal cortex, the brain's center for rational thought. Typically, the prefrontal cortex regulates amygdala activity, thereby tempering emotional reactions. But, in the sleep-deprived brain, the amygdala is hyperactive and unrestrained. As a result, people are more sensitive to siren calls and less able to control their impulses.
But engaging in risky behavior may take more than being in an emotionally volatile and impulsive state. In some cases, taking risks takes effort. And, in an upcoming study from Iowa State University, effort emerged as a key factor in the sleep-risk equation.
Researchers, who presented their work at the 2017 SLEEP conference in June, chose to look at the relationship between risk-taking and sleepiness, which is a measure of your current propensity to fall asleep. Your level of sleepiness, at any given time of day, reflects sleep-wake factors other than how long you've been awake. Circadian rhythms also come into play. "For most people there is an increase in sleepiness in the afternoon, often colloquially referred to as the "post-lunch dip," study co-author Garrett Hisler told Van Winkle's.
The study involved 130 college students who assessed their levels of sleepiness immediately before performing a computerized task, called the BART. It's one of a few tools psychologists use to study impulsivity and risk-taking. And, in previous research, BART performance has accurately predicted real-life behavior related to gambling, drug and cigarette use, car crashes, unprotected sex and stealing.
The BART works like this: Participants earn real money by pumping (virtual) balloons. Each round, participants can choose to pump one balloon between 1 and 64 times, earning more money with each pump. But, the balloons will burst at some point before the 64th pump, and participants don't know when. If balloons burst while participants are still pumping, they lose all their money from that round. If they move on to the next round before their balloons burst, they keep their earnings.
BART has predicted all sorts of risky behavior. But the task of pumping a balloon to obtain money most closely resembles real-life risky activities that are effortful, such as playing blackjack or using slot machines. Both of these, Hisler said, involve "taking a risk to acquire a (usually small) reward and repeatedly putting effort into continuing to gamble to obtain more reward."
In other risk-taking situations, such as staying put when the fire alarm sounds or saying yes to unprotected sex, you can flirt with danger without expending much effort.
Hisler and his team proposed two hypotheses for how sleepiness would affect risk-taking on the BART. Based on a slim and inconsistent body of previous research, they first predicted that sleepier participants would take more risks. Alternatively, they floated the possibility of a curvilnear pattern, meaning that moderately sleepy participants would take more risks than participants who were either peppy or exhausted. The idea here is that, when people start to feel tired enough to fall asleep, they "disengage from pursuing rewards in the environment."
And that's what happened. Moderately sleepy participants spent more time on the BART, pumping and exploding more balloons. And, in this case, more time amounted to higher earnings. (Gambling doesn't always work out like that in real life, of course.) Researchers took into account other factors that might influence the risk-sleep relationship, including chronotype, time of day and propensity towards sensation-seeking. But, moderate sleepiness predicted risk-taking regardless.
While the study results make sense theoretically, this is actually the first study, to the authors' knowledge, to report a curvilinear relationship between sleepiness and risk-taking. But the idea that very sleepy people shy away from effortful risks is supported by other ongoing research: Researchers at Wayne University and Henry Ford Hospital are in the process of writing up a study on night-shift workers, who, on account of their wonky schedules, may keep hours that don't match their body clocks. This is called circadian misalignment, and it's likely to be correlated with sleepiness.
In this study, researchers found that, the sleepier participants were before beginning a risk-taking task (not the BART), the less likely they were to take risks. And, when very sleepy participants did take risks, they were less likely to succeed than their alert counterparts. The findings, according to study co-author Philip Cheng, "add to the literature that sleepiness does not always increase risk taking, but does impact how effective individuals are achieving success through their risk behaviors."
Both studies challenge the notion that sleepiness and risk-taking are associated in a uniform way. Cheng says his team will keep studying cognitive processes affected by shift-work-related circadian misalignment. "One avenue of continued research," Cheng said, "would be to see if manipulating circadian phase (e.g., improving circadian misalignment) would also show improvements in the success rate of risk-taking."
Hisler's team doesn't have any immediate plans to expand their risk-taking study, due to commitments to other projects. But, if they did explore the issue further, Hisler said, they'd try to replicate the findings to make sure they weren't a statistical fluke. Additionally, Hisler said he'd want to see if the same trend would emerge for less effortful risky behavior.
But, as it stands, the study already has real-world applications. Based on the findings, it would make sense to consider sleepiness as a factor in efforts to curb risky behavior, such as addiction therapy or initiatives to promote safe sex among teens. "Times or situations in which individuals are likely to be moderately sleepy (e.g., when the time-of-day does not match chronotype)," study authors wrote, "may be indicators of when individuals are the most likely to engage in pursuit of risky rewards or cave to appetitive impulses."
In other words? You may be more likely to take risks, and succeed at them, during your afternoon slump than after pulling an all-nighter.
"I'm not sure what kind of risky behaviors are most likely to occur during the middle of the day," said Hisler. "Perhaps more social risks such as lying or stealing office supplies may be more relevant in the afternoon."
Guard those Post-it notes.