Neural correlates of visuospatial working memory in the 'at-risk mental state'
Neural correlates of visuospatial working memory in the 'at-risk mental state'
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DOI：
10.1017/s0033291710000280
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发表时间：
2010-12-01
影响因子：
6.9
通讯作者：
McGuire, P. K.
中科院分区：
文献类型：
--
作者：
Broome, M. R.;Fusar-Poli, P.;McGuire, P. K.
背景受损的空间工作记忆（SWM）是精神分裂症的一个强大特征，并与处于危险精神状态（ARMS）的人发生精神病的风险有关。我们使用功能性磁共振成像（fMRI）来检查ARMS和刚刚发展为精神分裂症的患者SWM的神经底物。fMRI被用来研究17例ARMS患者，10例首次发作的精神病患者和15名年龄匹配的健康对照组。在实验操作记忆负荷的情况下，测量被试在进行物体位置配对联想记忆任务时的血氧水平依赖性（BOLD）反应。在所有组中，记忆负荷的增加与内侧额叶和内侧后顶叶皮层的激活有关。显著的组间激活差异在跨越内侧额叶皮层和右楔前叶的一个簇中是明显的，ARMS组显示出比对照组更少的激活，但比首发精神病（FEP）患者更大的激活。这些组间差异在最高要求的任务水平上比在简单水平上更明显。在所有组中，任务表现随着条件的重复而改善。然而，在重复试验中，右侧楔前叶的反应存在显著的组间差异，对照组激活减弱，但FEP激活增加，ARMS变化不大。在SWM任务期间，内侧额叶皮层和后顶叶皮层的异常神经活动可能是精神病易感性增加的神经相关性。
Background. Impaired spatial working memory (SWM) is a robust feature of schizophrenia and has been linked to the risk of developing psychosis in people with an at-risk mental state (ARMS). We used functional magnetic resonance imaging (fMRI) to examine the neural substrate of SWM in the ARMS and in patients who had just developed schizophrenia.Method. fMRI was used to study 17 patients with an ARMS, 10 patients with a first episode of psychosis and 15 age-matched healthy comparison subjects. The blood oxygen level-dependent (BOLD) response was measured while subjects performed an object-location paired-associate memory task, with experimental manipulation of mnemonic load.Results. In all groups, increasing mnemonic load was associated with activation in the medial frontal and medial posterior parietal cortex. Significant between-group differences in activation were evident in a cluster spanning the medial frontal cortex and right precuneus, with the ARMS groups showing less activation than controls but greater activation than first-episode psychosis (FEP) patients. These group differences were more evident at the most demanding levels of the task than at the easy level. In all groups, task performance improved with repetition of the conditions. However, there was a significant group difference in the response of the right precuneus across repeated trials, with an attenuation of activation in controls but increased activation in FEP and little change in the ARMS.Conclusions. Abnormal neural activity in the medial frontal cortex and posterior parietal cortex during an SWM task may be a neural correlate of increased vulnerability to psychosis.