London: Pathological gamblers ‘see’ patterns in things that are actually quite random and not really there, to such a degree that they are quite willing to impulsively bet good money on such illusory patterns, a new study finds.

‘Our results suggest that gamblers are more willing to bet impulsively on perceived illusory patterns,’ said lead researcher Wolfgang Gaissmaier from the University of Konstanz in Germany.

‘They are overly prone to accept random series of events as, in fact, nonrandom - and nonrandom enough to be worth betting on,’ Gaissmaier added.

The findings add to a large body of research that suggests that cognitive distortions play an important role in pathological gambling.

In a laboratory setting, the researchers compared the betting habits of 91 habitual gamblers against 70 community members.

Participants were shown a picture of a casino and two slot machines and had to predict on many trials whether a coin would be obtained from the slot machine on the right or the left.

The probability of winning was higher on one slot machine (67 percent winning chance) than on the other (33 percent winning chance), and the order of outcomes was completely random.

The best thing one can do in this task is to always bet on the better slot machine, which yields an expected accuracy of 67 percent.

However, many people tend to match their response proportions to the outcome probabilities - they bet on the better slot machine in 67 percent of the cases, and on the worse one in 33 percent of the cases.

Such 'probability matching' only yields an expected accuracy of 55.6 percent.

‘The results showed that gamblers demonstrated more probability matching behaviour and are thus obviously more likely to perceive illusory patterns,’ the study noted.

Gamblers also scored much lower on the cognitive reflection task, which measures impulsivity.

‘Humans are generally very good at detecting actual patterns. However, as a side effect of that ability, they also fall prey to seeing illusory patterns,’ Gaissmaier said.

The study appeared in Springer's Journal of Gambling Studies.