Working memory and DLPFC inefficiency in schizophrenia: The FBIRN study
Working memory and DLPFC inefficiency in schizophrenia: The FBIRN study
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DOI：
10.1093/schbul/sbn162
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发表时间：
2009-01-01
影响因子：
6.6
通讯作者：
Lim, K. O.
中科院分区：
文献类型：
--
作者：
Potkin, S. G.;Turner, J. A.;Lim, K. O.
背景：功能成像生物医学信息学网络是一个为多站点功能成像研究开发方法的联盟。在以往的工作记忆研究中，慢性精神分裂症患者的前额叶活动亢进或减退都已被发现。研究方法：在这项关于工作记忆的功能性磁共振成像（fMRI）研究中，从美国10所大学招募了128名慢性精神分裂症患者和128名年龄和性别匹配的对照组。受试者进行斯滕贝格项目识别范式1，2与记忆负荷的1，3，或5个项目。感兴趣的区域分析研究的平均BOLD信号变化的地图为基础的划分的背外侧前额叶皮层（DLPFC），在这两个组中，在编码和检索阶段的实验在不同的记忆负荷。结果如下：精神分裂症受试者的表现略差，但明显低于健康志愿者，随着记忆负荷的增加，准确性下降幅度更大，反应时间增加。精神分裂症组DLPFC的平均BOLD信号显著高于健康组，特别是在中等负荷条件下。二次分析匹配受试者的平均准确性，并发现精神分裂症患者相同的BOLD信号过度反应。结论：精神分裂症患者BOLD信号从最小到中等记忆负荷的变化比对照组更大。当年龄，性别，跑步，半球和性能被考虑时，这种效果仍然存在，与工作记忆期间低效的DLPFC功能一致。从一个大的多站点样本的这些发现支持的概念，而不是hyperfrontality或hypofrontality精神分裂症，而是DLPFC的效率低下，可能会表现在任何一个方向取决于任务的要求。这将研究的重点从差异的方向转向了低效的神经机制。
Background: The Functional Imaging Biomedical Informatics Network is a consortium developing methods for multisite functional imaging studies. Both prefrontal hyper- or hypoactivity in chronic schizophrenia have been found in previous studies of working memory. Methods: In this functional magnetic resonance imaging (fMRI) study of working memory, 128 subjects with chronic schizophrenia and 128 age- and gender-matched controls were recruited from 10 universities around the United States. Subjects performed the Sternberg Item Recognition Paradigm 1,2 with memory loads of 1, 3, or 5 items. A region of interest analysis examined the mean BOLD signal change in an atlas-based demarcation of the dorsolateral prefrontal cortex (DLPFC), in both groups, during both the encoding and retrieval phases of the experiment over the various memory loads. Results: Subjects with schizophrenia performed slightly but significantly worse than the healthy volunteers and showed a greater decrease in accuracy and increase in reaction time with increasing memory load. The mean BOLD signal in the DLPFC was significantly greater in the schizophrenic group than the healthy group, particularly in the intermediate load condition. A secondary analysis matched subjects for mean accuracy and found the same BOLD signal hyperresponse in schizophrenics. Conclusions: The increase in BOLD signal change from minimal to moderate memory loads was greater in the schizophrenic subjects than in controls. This effect remained when age, gender, run, hemisphere, and performance were considered, consistent with inefficient DLPFC function during working memory. These findings from a large multisite sample support the concept not of hyper- or hypofrontality in schizophrenia, but rather DLPFC inefficiency that may be manifested in either direction depending on task demands. This redirects the focus of research from direction of difference to neural mechanisms of inefficiency.