Gambling is a thriving form of entertainment in the UK, but may also become a form of addiction for some individuals. Just why do people gamble when ‘the house always wins’? Advances in brain imaging techniques are helping Cambridge scientists find out.
Gambling is a thriving form of entertainment in the UK, but may also become a form of addiction for some individuals. Just why do people gamble when ‘the house always wins’? Advances in brain imaging techniques are helping Cambridge scientists find out.
Gambling games promote an ‘illusion of control’: the belief that the gambler can exert skill over an outcome that is actually defined by chance.
Dr Luke Clark
Gambling is a thriving form of entertainment in the UK, but may also become a form of addiction for some individuals. Just why do people gamble when ‘the house always wins’? Advances in brain imaging techniques are helping Cambridge scientists find out.
Gambling has been a popular source of entertainment for many centuries and across many cultures. With current changes in gambling legislation in the UK, its popularity looks set to continue. New casinos are to be established, including a large ‘super-casino’, and novel forms of gambling like internet gambling and electronic gaming machines are flourishing. Some argue these changes are a good thing: gambling is a recreational activity enjoyed by around 70% of the British public at least annually, and the gambling industry is a useful source of taxable revenue.
But all this comes at a cost – for a minority of individuals, gambling is a spiralling habit that they become unable to control. Problem (or ‘pathological’) gambling is a recognised psychiatric diagnosis present in around 1% of the population. These prevalence rates are higher in local communities around gambling facilities, and clinicians are concerned that the relaxation of British legislation will increase the incidence of problem gambling in years to come.
Against the odds
At its heart, gambling is a rather paradoxical behaviour because it is widely known that ‘the house always wins’. Whether you are gambling on fruit machines, horseracing, blackjack or roulette, the odds will have been meticulously arranged to ensure a steady profit for the casino or bookmaker. The only way to achieve this is for the gambler to make a steady loss. So why do gamblers, and particularly problem gamblers, continue to play when the overwhelming likelihood is that they will lose money?
Dr Luke Clark, in the Department of Experimental Psychology, is interested in the different ways in which gamblers over-estimate their chances of winning, including the effects of near-misses and personal choice. These features of gambling games promote an ‘illusion of control’: the belief that the gambler can exert skill over an outcome that is actually defined by chance.
Imaging the gambling brain
Recent advances in brain imaging technology are helping scientists to understand how these features of gambling games are so effective in maintaining continued play. At the Wolfson Brain Imaging Centre at Addenbrooke’s Hospital in Cambridge, Dr Clark is using functional magnetic resonance imaging (fMRI) to measure patterns of brain activity while volunteers perform a gambling game.
Previous research has shown a reliable pattern of brain activity when humans receive monetary wins. In particular, a region called the striatum, near the centre of the brain, is a crucial component in a reward circuit that also responds to natural reinforcers like food and sexual stimuli, as well as drugs of abuse like cocaine. In ongoing research, Dr Clark is measuring activity in this reward circuit as volunteers experience near-misses and choice effects during a gambling task.
Hallmarks of addiction
Both near-misses and personal choice cause gamblers to play for longer and to place larger bets. Over time, these distorted perceptions of one’s chances of winning may precipitate ‘loss chasing’, where gamblers continue to play in an effort to recoup accumulating debts. Loss chasing is one of the hallmarks of problem gambling, which actually bears much resemblance to drug addiction. Problem gamblers also experience cravings and symptoms of withdrawal when denied the opportunity to gamble.
In addition to an array of psychological factors, problem gambling may also have some important biological determinants. The brain chemical dopamine is known to play a key role in drug addiction and may also be abnormally regulated in problem gambling. Patients with Parkinson’s disease, who show degeneration of dopamine cells, can sometimes show a sudden interest in gambling, linked to their use of medications that increase dopamine transmission. Other systems in the brain are also critical, particularly the part of the frontal lobes immediately above the eye sockets, known as the orbitofrontal cortex.
Following damage to the orbitofrontal region, neurosurgical patients often show changes in their judgment and risk-taking. One patient, examined at the University of Iowa, made a series of disastrous decisions involving extravagant business ventures and dubious personal relationships after having a tumour removed from his orbitofrontal cortex. In a collaborative study with Dr Antoine Bechara at the University of Southern California, Dr Clark is measuring betting behaviour in a group of similar patients with damage in this region, using a simple gambling task. More subtle chemical imbalances in this brain region may accompany the transition from regular gambling to problem gambling.
Help for problem gamblers?
By further understanding the breakdown of self-control in gamblers, this programme of research carries important implications for the treatment of problem gambling, using both pharmacological and psychological therapies. Moreover, the development of objective tasks of gambling will provide more valid outcome measures for assessing the effectiveness of new treatments. By understanding how subtle features of gambling games, like near-misses and personal choice, are linked to the addictiveness of these games, future changes in gambling legislation may be in a better position to protect vulnerable individuals.
Promoting an illusion of control
Near-missesoccur when the outcome is close to the jackpot, but there is no actual win. Near-misses are common in many forms of gambling, such as when your chosen horse finishes in second place in a horserace. A moderate frequency of near-misses encourages prolonged gambling, even in student volunteers who do not gamble on a regular basis. Problem gamblers often interpret near-misses as evidence that they are mastering the game and that a win is on the way.
Personal choiceis a further determinant of illusory control, referring to situations where the gambler has some responsibility in arranging their gamble. As an example, roulette players will place higher bets if they can throw the ball onto the roulette wheel themselves, compared with if the croupier throws the ball for them. Lottery players often prefer a number sequence they have selected themselves, and may refuse to exchange their ticket for several tickets of random numbers. Choice appears to encourage a belief that the game involves skill when in fact the outcome is entirely random.
For more information, please go towww.psychol.cam.ac.uk/BCNIor contact the author Dr Luke Clarklc260@cam.ac.uk
This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.
