A systematic fMRI investigation of the brain systems subserving different working memory components in schizophrenia
A systematic fMRI investigation of the brain systems subserving different working memory components in schizophrenia
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DOI：
10.1111/j.1460-9568.2009.06850.x
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发表时间：
2009-08-01
影响因子：
3.4
通讯作者：
Gruber, O.
中科院分区：
文献类型：
--
作者：
Henseler, I.;Falkai, P.;Gruber, O.
工作记忆障碍是精神分裂症的主要认知障碍之一，相当多的证据表明，它可以追溯到大脑的功能改变。然而，具体赤字与地区性特定功能障碍的确切分配仍然难以捉摸。本研究的目的是检测精神分裂症患者工作记忆维持相关亚过程(发音复述、非发音维持语音信息、视觉空间信息维持)的三个不同大脑系统的功能完整性。使用一种旨在选择性激活这些不同大脑系统的实验范式，我们用功能磁共振成像评估了患者和对照组的大脑激活情况。与对照组相比，患者在非发音维持语音信息的过程中，额盖皮质、顶叶内皮质和前扣带回皮质的激活减少，海马区的失活减弱。此外，我们发现前额叶激活严重依赖于患者当前的症状状态。在视觉空间维持期间，患者表现出顶上、颞叶和枕叶皮质的激活受损，同时额叶眼场和顶下皮质的激活增强。在发音排练任务中没有观察到异常激活。所有的激活差异都与任务绩效的组间差异无关。我们对工作记忆电路特定方面的功能障碍的细粒度分析为精神分裂症中支持工作记忆亚成分的大脑系统提供了不同程度的损伤证据，并扩大了对认知缺陷、大脑激活异常和精神分裂症症状之间关系的认识。
Working memory impairment is one of the cardinal cognitive disturbances in schizophrenia and considerable evidence suggests that it can be traced to functional alterations in the brain. The exact allocation of specific deficits to regional specific dysfunctions, however, remains elusive. The aim of this study was to examine the functional integrity of three distinguishable brain systems underlying maintenance-related subprocesses of working memory (articulatory rehearsal, non-articulatory maintenance of phonological information, maintenance of visuospatial information) in patients with schizophrenia. Using an experimental paradigm, which had been designed to selectively activate these different brain systems, we assessed the brain activation of patients and controls with functional magnetic resonance imaging. Compared with controls, patients showed reduced activation of the fronto-opercular, intraparietal and anterior cingulate cortex during the non-articulatory maintenance of phonological information, as well as attenuated deactivation of the hippocampus. Additionally, we found prefrontal activation to depend critically on the patients' current symptom status. During visuospatial maintenance, patients showed impaired activation of the superior parietal, temporal and occipital cortex, combined with enhanced activation of the frontal eye field and the inferior parietal cortex. No abnormal activations were observed during the articulatory rehearsal task. All activation differences were independent of group differences in task performance. Our fine-grained analysis of dysfunctions in particular aspects of working memory circuitry provides evidence for a differential impairment of the brain systems supporting working memory subcomponents in schizophrenia and extends knowledge of the relationship between cognitive deficits, brain activation abnormalities and symptoms in schizophrenia.