Event-related functional magnetic resonance imaging changes during relational retrieval in normal aging and amnestic mild cognitive impairment.
Event-related functional magnetic resonance imaging changes during relational retrieval in normal aging and amnestic mild cognitive impairment.
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DOI：
10.1017/s1355617712000689
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发表时间：
2012-09
影响因子：
2.6
通讯作者：
Welsh-Bohmer, Kathleen A.
中科院分区：
文献类型：
--
作者：
Giovanello, Kelly S.;De Brigard, Felipe;Ford, Jaclyn Hennessey;Kaufer, Daniel I.;Burke, James R.;Browndyke, Jeffrey N.;Welsh-Bohmer, Kathleen A.
在健忘性轻度认知障碍（aMCI）中观察到的最早的认知缺陷似乎集中在需要关系记忆（RM）的记忆任务上，即连接或整合不相关信息的能力。aMCI的RM损伤可能反映了内侧颞叶（MTL）和后顶叶皮层（PPC）的神经变化。我们测试了一个假设，即与认知正常（CN）对照相比，患有aMCI的个体会招募MTL和PPC以外的神经区域来支持关系记忆。为此，我们使用事件相关功能磁共振成像（fMRI），在保持刺激和编码任务不变的情况下，直接比较了aMCI组和CN组成功的关系检索的神经基础。fMRI数据显示，与aMCI组相比，CN组在关系检索过程中激活了左侧楔前叶、左侧角回、右侧扣带回后叶和右侧海马旁皮层，而aMCI组相对于CN组激活了颞上回和边缘上回。这些发现表明aMCI中关系检索功能神经结构的早期转变，并可能在未来的研究中证明有用，旨在利用功能完整的神经区域作为治疗和减缓病程的目标。
The earliest cognitive deficits observed in amnestic mild cognitive impairment (aMCI) appear to center on memory tasks that require relational memory (RM), the ability to link or integrate unrelated pieces of information. RM impairments in aMCI likely reflect neural changes in the medial temporal lobe (MTL) and posterior parietal cortex (PPC). We tested the hypothesis that individuals with aMCI, as compared to cognitively normal (CN) controls, would recruit neural regions outside of the MTL and PPC to support relational memory. To this end, we directly compared the neural underpinnings of successful relational retrieval in aMCI and CN groups, using event-related functional magnetic resonance imaging (fMRI), holding constant the stimuli and encoding task. The fMRI data showed that the CN, compared to the aMCI, group activated left precuneus, left angular gyrus, right posterior cingulate, and right parahippocampal cortex during relational retrieval, while the aMCI group, relative to the CN group, activated superior temporal gyrus and supramarginal gyrus for this comparison. Such findings indicate an early shift in the functional neural architecture of relational retrieval in aMCI, and may prove useful in future studies aimed at capitalizing on functionally intact neural regions as targets for treatment and slowing of the disease course.