Patients with schizophrenia make decisions on the basis of less evidence when required to collect information to make an inference, a behavior often called jumping to conclusions. The underlying basis for this behaviour remains controversial. We examined the cognitive processes underpinning this finding by testing subjects on the beads task, which has been used previously to elicit jumping to conclusions behaviour, and a stochastic sequence learning task, with a similar decision theoretic structure. During the sequence learning task, subjects had to learn a sequence of button presses, while receiving noisy feedback on their choices. We fit a Bayesian decision making model to the sequence task and compared model parameters to the choice behavior in the beads task in both patients and healthy subjects. We found that patients did show a jumping to conclusions style; and those who picked early in the beads task tended to learn less from positive feedback in the sequence task. This favours the likelihood of patients selecting early because they have a low threshold for making decisions, and that they make choices on the basis of relatively little evidence.

Background We were interested in examining the relationship between socially-relevant stimuli and decision processes in patients with schizophrenia. Methods We tested patients with schizophrenia and healthy controls on a stochastically-rewarded associative learning task. Participants had to determine through trial and error which of two faces was associated with a higher chance of reward. One face was angry, the other happy. Results Both patients and healthy controls were able to do the task at above-chance accuracy, and there was no significant difference in overall accuracy between groups. Both groups also reliably preferred the happy face, such that they selected it more often than the angry face on the basis of the same amount of positive vs. negative feedback. Interestingly, however, patients were significantly more averse to the angry face, such that they chose it less often than control participants when the reward feedback strongly supported the angry face as the best choice. Conclusions Patients show an increased aversion to angry faces, in a task in which they must learn to associate rewards with expressions.