To investigate contextual reward-processing in pathological gambling , a slot-machine fMRI task was performed by three groups ( with pathological gambling , cocaine dependence and neither disorder ; N = @ each ) to determine the extent to which two groups with addictions ( non-substance-related and substance-related ) showed similarities and differences with respect to each other and a non-addicted group during anticipatory periods and following the delivery of winning , losing and ` near-miss ' outcomes .