Inefficient neural activity in patients with schizophrenia and nonpsychotic relatives of schizophrenic patients: Evidence from a working memory task
Inefficient neural activity in patients with schizophrenia and nonpsychotic relatives of schizophrenic patients: Evidence from a working memory task
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DOI：
10.1016/j.jpsychires.2009.04.004
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发表时间：
2009-10-01
影响因子：
4.8
通讯作者：
Mulert, Christoph
中科院分区：
文献类型：
--
作者：
Karch, Susanne;Leicht, Gregor;Mulert, Christoph
对精神分裂症的功能性MRI研究显示，包括前额叶皮质在内的大脑各个区域都出现了高激活和低激活。在精神分裂症患者的一级亲属中也有功能异常的报道。本研究旨在研究健康受试者、精神分裂症患者和未受影响亲属的工作记忆相关脑功能，并确定精神病理对这些过程的影响。采用参数化n-back工作记忆任务和功能MRI对61例精神分裂症患者、11例精神分裂症患者的非精神病性亲属和61名健康受试者进行了检查。结果表明，与对照组相比，精神分裂症患者的脑功能随任务难度和表现的不同而增加或减少：在作为对照条件的注意任务（0-back）中，精神分裂症患者的行为反应与健康者几乎没有差异，但精神分裂症患者的BOLD反应明显增强。随着任务难度的增加，BOLD反应的组间差异减小，而患者的行为缺陷增加。对注意独立工作记忆功能（2- vs. 0-back）的检查在患者中产生低激活，特别是在额叶，颞叶和皮层下脑区。此外，阳性症状与顶叶功能障碍有关。精神分裂症患者未受影响亲属的行为表现和神经反应介于精神分裂症患者和对照组之间，表明轻度脑功能障碍。此外，还对补偿策略进行了论证。这些发现表明，精神分裂症的遗传风险伴随着神经效率低下，这与认知缺陷有关，特别是在困难的任务中。2009爱思唯尔有限公司版权所有。
Studies of schizophrenia with functional MRI have shown hyper- and hypoactivations in various brain regions including the prefrontal cortex. Functional anomalies have also been reported in first-degree relatives of schizophrenic patients. The aim of this study was to examine working memory related brain functions in healthy subjects, schizophrenic patients and unaffected relatives and to determine the influence of psychopathology on these processes. A parametric n-back working memory task and functional MRI were used to examine 61 patients with schizophrenia, 11 nonpsychotic relatives of schizophrenic patients and a comparison group of 61 healthy subjects. The results indicated increased as well as decreased brain functions in schizophrenic patients compared to the control group depending on the task difficulty and the performance: during the attention task (0-back), which served as control condition, behavioral responses of patients and healthy subjects hardly differed but BOLD responses were considerably enhanced in schizophrenic patients. With increasing task difficulty differences between groups in BOLD responses diminished whereas behavioral deficits of patients increased. The examination of attention-independent working memory-functions (2- vs. 0-back) produced hypoactivations in patients, especially in frontal, temporal and subcortical brain regions. Furthermore, positive symptoms were associated with parietal dysfunctions. Behavioral performance and neural responses of unaffected relatives of schizophrenic patients were intermediate between schizophrenic patients and controls indicating slight brain dysfunctions. in addition, compensatory strategies were demonstrated. These findings suggest that the genetic risk for schizophrenia is accompanied by neural inefficiency which is associated with cognitive deficits, especially in difficult tasks. (C) 2009 Elsevier Ltd. All rights reserved.