Almost winning causes some people to carry on gambling

The research, published in the journal Neuron, provides some insight into why some people carry on gambling to the point of compulsion.

Research has shown that near-misses (such as two cherries on the slot machine) and a sense of control over the game (such as the chance to throw the dice) promote gambling tendencies and may be associated with the addictiveness of gambling. However, little is known about the brain mechanisms involved.

Researchers devised a series of experiments to elicit near-miss and control phenomena in the laboratory and used functional magnetic resonance imaging (fMRI) to explore the brain mechanisms underlying these cognitive distortions.

Near-misses were associated with a significant activation of the ventral striatum and anterior insula, areas that were also activated by unpredictable monetary wins. There was a significant positive relationship between insula activity to near-misses and a questionnaire measure of gambling propensity that is significantly elevated in problem gamblers. Interestingly, the insula has been implicated in drug craving and other addictive behaviors.

Although near-misses were rated by subjects as more unpleasant than full-misses, they also increased the desire to play the game. These subjective effects were only observed when the subject had control over arranging the gamble. The interaction between near misses and personal control was also reflected in the fMRI data in the medial and frontal cortex.

The brain apparently responds to a near miss in the same way as it does to a win, which will encourage people to continue gambling.