I've always believed that Las Vegas is a powerful window into human nature. On the one hand, the act of gambling in a casino is a deeply irrational behavior: the odds are clearly stacked against us. Over the long run, we are all going to lose lots of money playing these dumb games of chance. And yet, Vegas is fun! There is something perversely pleasurable about putting quarter after quarter into a slot machine, or seeing if a bouncing ball lands on a red number, or rolling a pair of dice on a green felt table.
The question, of course, is why Vegas is fun. Why do we choose to squander our hard earned cash on various forms of randomness?
A new paper in Neuropsychopharmacology, by neuroscientists at the University of British Columbia and Oxford University, helps explain the allure. Their answer revolves around the potency of near-misses, or those moments when we almost win. Think, for instance, of a slot machine showing two cherries instead of three, or a blackjack hand that adds up to 22, or a roulette spin that lands on 17 instead of 18. Such losses are excruciating. And extremely exciting. In fact, previous research has shown that near-misses on a slot machine are especially intoxicating for compulsive gamblers, leading to a spike in activity in the dopaminergic midbrain.
This new paper on near-misses investigates the molecular mechanics of the near-miss effect. The scientists began by setting up a clever paradigm to test rat behavior, a kind of casino for rodents. There were three flashing lights above the cage, "loosely analogous" to the three wheels of a slot machine. If all three lights turned on simultaneously, the rat won the game, which meant the animal could collect a rewarding pellet of food by pressing a lever. However, if the rats pressed this lever when they hadn't won the game - not all three lights were on - then the lever inflicted a time penalty, and they had to wait a few minutes before the lights would flash again. Waiting sucks.
Here's where the results get interesting: While the rats were much more likely to press the collect lever after a winning trial (three lights), they also tended to press the lever when only two lights flashed (a near-miss). According to the scientists, this suggests that near-misses have some intrinsic appeal for our reward circuity, tricking those brain cells into believing that we won even though we actually lost. Furthermore, various drug manipulations dramatically skewed the behavior of the animals. When they were given various compounds that increase the release of dopamine in the synapse - such as amphetamines or dopamine receptor agonists - they became even more likely to seek a reward after a near-miss, even though this led to a time penalty. This suggests that, from the perspective of our dopamine neurons, near misses are virtually indistinguishable from actual wins. Both forms of feedback tickle our reward circuitry, which is why Vegas invests in games and algorithms that are full of close calls. For a casino, the beauty of a near miss is clear: Although we've lost money, if feels as if we won. As a result, the casino is able to make us happy while robbing us blind.
Why would the mammalian brain be designed this way? One answer is that we didn't evolve for Vegas. Rather, near misses help us stay motivated when engaged in activities that require actual skill, and not dumb luck. Let's say we're learning to play basketball. At first, our shots are going to be all over the place, a seemingly random distribution of bricks and airballs. And yet, as we slowly get better, those shots will get closer to the rim. A few might even go in, which is pretty thrilling. The purpose of near misses, then, is to keep us motivated while we slowly improve our form. If we only got excited by makes, we'd quickly give up, which is why the brain also needs a mechanism to register progress.
And yet, this useful cellular mechanism is cruelly misled by games of chance. There is no skill with slot machines; throwing dice doesn't take talent. And so our near miss dopamine neurons - these peppy cheerleaders in the brain - urge us onwards, insisting that we keep on playing. Alas, the only thing we're getting better is losing money.
PS. Thanks to David Dobbs for the tip!
Photo credit: Flickr/Marionzetta
