Gambling is a popular recreational pastime that becomes excessive in a minority of the population. Problem gamblers typically display a number of distorted cognitive beliefs ('cognitive biases') that cause them to overestimate their chances of winning. The proposed research will take a psychological and biological approach to investigate two common biases, which occur across many forms of gambling. In the 'near-miss' effect, gambling is encouraged by failures that are close to the winning outcome, such as a chosen horse finishing in second place. In the 'illusion of control', gamblers are more confident when they have played an active role in the betting process, for example, if they select their own lottery numbers. We will use a brain scanning technique (functional MRI) to measure brain responses in a group of problem gamblers and a group of social gamblers. Participants will perform a simplified gambling task whilst they lie in the MRI scanner. We propose that the brain is naturally configured to respond to near-misses and to wins that derive from one's own behaviour. We hypothesise that these normal responses are exaggerated in problem gamblers, and associated with the transition from social gambling to problem gambling.

The slot machine task saves an output file containing the responses and timings for each subject. An Excel macro was used to extract the mean values for each trial type, for each subject. Questionnaire data were scored by hand and entered manually. fMRI data are stored by the MRI scanner, and downloaded to a specialised and secure server for image processing. The timing of each scan is stored in the task output file to allow precise synchronisation of MRI data to task variables.