title: Impaired error-likelihood prediction in medial prefrontal cortex in schizophrenia.
abstract: The cognitive impairment in individuals with schizophrenia includes deficits of working memory in dorsolateral prefrontal cortex and deficits of performance monitoring in medial prefrontal cortex (MPFC). Recent work suggests a more general role for MPFC in predicting the outcome of actions and then evaluating those predictions. Here we investigate, in individuals with schizophrenia, two specific effects associated with this role: the error likelihood effect (occurring on trials with correct performance, but features that predict a high probability of errors), and the error unexpectedness effect (occurring on trials with an error, but features that predict errors are of low probability). In a rapid event-related fMRI design with a modified version of the change-signal task, a cue incidentally predicting error likelihood was encoded into working memory by participants in order to perform a secondary delayed match-to-sample task. There were four key findings: (1) individuals with schizophrenia exhibited poorer working memory performance and reduced error signals in MPFC; (2) even in control and schizophrenia subgroups matched on working memory performance, the schizophrenia subgroup showed a deficit in error-likelihood prediction in MPFC at the time of the predictive cue; (3) the schizophrenia subgroup also showed a deficit in evaluative error-unexpectedness activity when errors were committed; and (4) a mediation analysis indicated that error-likelihood predictions successfully explained error-unexpectedness evaluations in both controls and patients. Collectively, these findings suggest that individuals with schizophrenia have a disturbance in the evaluation of outcomes that is the result of a primary deficit in the prediction of error likelihood in MPFC.
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA. akrawitz@indiana.edu
authors.forename: Adam
authors.initials: A
authors.lastname: Krawitz
authors.forename: Todd S
authors.initials: TS
authors.lastname: Braver
authors.forename: Deanna M
authors.initials: DM
authors.lastname: Barch
authors.forename: Joshua W
authors.initials: JW
authors.lastname: Brown
mesh_terms: D000328:Adult; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*