Executive function in first-episode schizophrenia: A three-year longitudinal study of an ecologically valid test
ABSTRACT Executive function impairment is a key cognitive deficit in schizophrenia. However, traditional neuropsychological tests of executive function may not be sensitive enough to capture the everyday dysexecutive problems experienced by patients. Additionally, existing literature has been inconsistent about longitudinal changes of executive functions in schizophrenia. The present study focuses on examining the longitudinal change of executive functions in schizophrenia using the Modified Six Elements Test (MSET) that was developed based on the Supervisory Attentional System model and shown to be sensitive to everyday dysexecutive problems. In the present study, MSET performance was assessed in 31 medication-naïve first-episode schizophrenic patients at four times over a period of three years, while the 31 normal controls were assessed once. Patients demonstrated impairment in MSET as compared to controls. Importantly, the MSET impairment persisted from the medication-naïve state to clinical stabilization and the three years following the first psychotic episode though patients improved in a conventional executive test (Modified Wisconsin Card Sorting Test). Performance was not related to intelligence, educational level, symptom changes, age-of-onset, or duration of untreated psychosis. Better MSET performance at medication-naïve state predicted improvement in negative and positive symptoms over the three-year period. These findings may suggest that MSET impairment is a primary deficit in schizophrenia that occurs early in the course of the illness and remains stable irrespective of clinical state for at least three years following the first episode of schizophrenia.
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ABSTRACT: Effective integration of visual information is necessary to utilize abstract thinking, but patients with schizophrenia have slow eye movement and usually explore limited visual information. This study examines the relationship between abstract thinking ability and the pattern of eye gaze in patients with schizophrenia using a novel theme identification task. Twenty patients with schizophrenia and 22 healthy controls completed the theme identification task, in which subjects selected which word, out of a set of provided words, best described the theme of a picture. Eye gaze while performing the task was recorded by the eye tracker. Patients exhibited a significantly lower correct rate for theme identification and lesser fixation and saccade counts than controls. The correct rate was significantly correlated with the fixation count in patients, but not in controls. Patients with schizophrenia showed impaired abstract thinking and decreased quality of gaze, which were positively associated with each other. Theme identification and eye gaze appear to be useful as tools for the objective measurement of abstract thinking in patients with schizophrenia.Behavioral and Brain Functions 04/2014; 10(1):13. DOI:10.1186/1744-9081-10-13 · 2.00 Impact Factor
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ABSTRACT: Background: Many studies had reported that neurocognitive impairments were evident during the active psychotic symptoms of schizophrenia but questions remain about whether these impairments were present even in absence of psychotic symptoms. Aim of the work: to assess and compare neuropsychological cognitive functioning of patients with schizophrenia in remission to their healthy counterparts. Methods: Cognitive functions (executive function, memory, attention and concentration) of a group of patients with schizophrenia in remission were compared with a control group, using SPSS. Results: Patients with schizophrenia showed impairment in attention, executive function and memory when compared to healthy control. The total length of hospitalizations in schizophrenia patients was associated with more declines in the processing speed. Conclusions: Schizophrenia patients had evident cognitive impairments even during remission. Processing speed decline was correlated with the total length of hospitalizations in schizophrenia patients. Keywords: cognitive performance, neuropsychological, remission, schizophrenia.
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ABSTRACT: The Modified Six Elements Test (MSET) assesses several executive functions. We examined whether an adapted scoring method is appropriate for discriminating between brain-injured persons with and without executive deficits. A MSET was administered to 70 participants with acquired brain injury in the chronic phase. The group was divided into individuals with and without executive impairments based on several other executive tests. The discriminative value for both the conventional raw score and the adapted scoring method was evaluated using receiver operating characteristic analyses. Both scoring methods discriminated significantly between persons with impaired and unimpaired executive functions (raw score: area under the curve, AUC = 0.703, p = .004; adapted score: AUC = 0.780, p = .000). Only the adapted scoring method proved sensitive (81%) and specific (67%) within a clinically useful range. Within this range, an acceptable cut-off score could be determined. Altogether, the proposed MSET scoring index is a potentially clinically useful contribution to the measurement of executive functions. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: email@example.com.Archives of Clinical Neuropsychology 12/2014; 30(2). DOI:10.1093/arclin/acu093 · 1.92 Impact Factor