title: Jumping to conclusions in schizophrenia.
abstract: Schizophrenia is a mental disorder associated with a variety of symptoms, including hallucinations, delusions, social withdrawal, and cognitive dysfunction. Impairments on decision-making tasks are routinely reported: evidence points to a particular deficit in learning from and revising behavior following feedback. In addition, patients tend to make hasty decisions when probabilistic judgments are required. This is known as "jumping to conclusions" (JTC) and has typically been demonstrated by presenting participants with colored beads drawn from one of two "urns" until they claim to be sure which urn the beads are being drawn from (the proportions of colors vary in each urn). Patients tend to make early decisions on this task, and there is evidence to suggest that a hasty decision-making style might be linked to delusion formation and thus be of clinical relevance. Various accounts have been proposed regarding what underlies this behavior. In this review, we briefly introduce the disorder and the decision-making deficits associated with it. We then explore the evidence for each account of JTC in the context of a wider decision-making deficit and then go on to summarize work exploring JTC in healthy controls using pharmacological manipulations and functional imaging. Finally, we assess whether JTC might have a role in therapy.
authors.affiliation: School of Psychology, University of Sussex, Brighton, East Sussex, UK.
authors.forename: Simon L
authors.initials: SL
authors.lastname: Evans
authors.affiliation: Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Bruno B
authors.initials: BB
authors.lastname: Averbeck
authors.affiliation: Department of Psychology, Royal Holloway, University of London, Egham, Surrey, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Furl
keywords: decision making; delusions; fMRI; ketamine; urn task