Error-monitoring abnormalities may underlie positive symptoms of schizophrenia. Response-synchronized event-related potentials during picture-word matching yielded error- and correct-response-related negativity (ERN, CRN) and positivity (Pe, Pc) and preresponse lateralized readiness potentials (LRP) from 18 schizophrenic patients and 18 controls. Both groups responded faster to matches than nonmatches, although patients were generally slower and made more errors to nonmatches. Compared with controls, patients, particularly with paranoid subtype, had smaller ERNs and larger CRNs, which were indistinguishable. LRPs showed evidence of more response conflict before errors than before correct responses in controls but not patients. Despite ERN/CRN abnormalities, post-error slowing and Pe were normal in patients, suggesting a dissociation of ERN and error awareness. Anterior cingulate and dorsolateral prefrontal cortical dysfunction in schizophrenia are implicated.
The Claremont Graduate School This study tested the generalizability of the consistency effect to real-world settings. The consistency effect refers to the finding that items inconsistent with expectations are better recalled and recognized than items consistent with expectations. In two experiments, subjects walked into a graduate student's office or a preschool classroom. Half of the items in each setting were consistent with expectations about that setting, and half were inconsistent. A recall and a samechanged recognition memory test followed immediately or 1 day later. In both experiments, the consistency effect was affirmed; items inconsistent with expectations were significantly better recalled and recognized than items consistent with expectations. This result is discussed in terms of differences in the encoding processes that operate on inconsistent and consistent items. The present study extends the generalizability of results from picture memory studies to real-world settings.
Font-specificity in visual word-stem completion priming was examined in patients with global amnesia and Patient M.S., who had a right-occipital lobectomy. Word-stems appeared in the same or different font as study words. Amnesic patients showed normal font-specific priming (greater priming for words studied in the same than different font as test), despite impaired word-stem cued recall. Patient M.S. failed to exhibit font-specific priming, despite preserved declarative memory. Therefore, perceptual specificity in visual priming depends on visual processes mediated by the right-occipital lobe rather than medial temporal and diencephalic regions involved in declarative memory.
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