Impaired decision-making on the basis of both reward and punishment information in individuals with psychopathy

In this study, we examined decision-making to rewarding or punishing stimuli in individuals with psychopathy (n = 21) and comparison individuals (n = 19) using the Differential Reward/Punishment Learning Task. In this task, the participant chooses between two objects associated with different levels of reward or punishment. Thus, response choice indexes not only reward/punishment sensitivity but also sensitivity to reward/punishment level according to inter-stimulus reinforcement distance. Individuals with psychopathy showed significant impairment when choosing between objects associated with differential levels of reward but also significantly greater impairment when choosing between objects associated with differential levels of punishment. However, the two groups were comparably affected by inter-stimulus reinforcement distance. The results are discussed with reference to current models of psychopathy. 2006 Elsevier Ltd. All rights reserved.