The intersubject and intrasubject reproducibility of FMRI activation during three encoding tasks: implications for clinical applications
The intersubject and intrasubject reproducibility of FMRI activation during three encoding tasks: implications for clinical applications
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DOI：
10.1007/s00234-006-0083-2
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发表时间：
2006-07-01
期刊：
影响因子：
2.8
通讯作者：
Yonelinas, Andrew P.
中科院分区：
文献类型：
--
作者：
Harrington, Greg S.;Farias, Sarah Tomaszewski;Yonelinas, Andrew P.
本研究的目的是评估FMRI激活的三个记忆编码任务的主体间和主体内的可重复性，这些任务以前用于手术前的功能映射。主要感兴趣区（ROI）是内侧颞叶（MTL）。相对的roi包括额下回和梭状回，它们受敏感性引起的信号损失的影响比MTL区域小。采用三种记忆编码范式：词对编码、模式编码和场景编码对18名被试进行扫描。9名受试者接受重复扫描。通过检查在给定ROI内显示激活的受试者百分比以及个体侧性指数（LIs）偏离平均值的范围，来评估FMRI激活的受试者间可重复性。通过检查LI测试-重测相关性、两次独立成像LI之间的平均差异以及激活体积（r -体积和r -重叠）的一致性比率来评估受试者内测试-重测的可重复性。对于场景编码，MTL内激活体积和li的再现性与梭状回和额下roi的再现性一样好或更好。对于模式编码和词对编码，MTL内的激活体积和li的再现性比梭状回和额下roi差。FMRI再现性的差异似乎更多地取决于任务而不是敏感性效应。本研究的结果表明，基于fmri的评估记忆的神经基质使用场景编码任务可能是一个有用的临床工具。
The goal of the present study was to evaluate the inter- and intrasubject reproducibility of FMRI activation for three memory encoding tasks previously used in the context of presurgical functional mapping. The primary region of interest (ROI) was the medial temporal lobe (MTL). Comparative ROIs included the inferior frontal and fusiform gyri which are less affected by susceptibility-induced signal losses than the MTL regions. Eighteen subjects were scanned using three memory encoding paradigms: word-pair, pattern, and scene encoding. Nine subjects underwent repeat scanning. Intersubject reproducibility of FMRI activation was evaluated by examining the percent of subjects who showed activation within a given ROI and the range to which individual laterality indices (LIs) varied from the mean. Intrasubject test-retest reproducibility was evaluated by examining the LI test-retest correlation, the average difference between LIs from two separate imaging sessions, and concordance ratios of activation volumes (R-volume and R-overlap). For scene encoding the reproducibility of activation volume and LIs within the MTL were as good as or better than the reproducibility within the fusiform and inferior frontal ROIs. For pattern encoding and word-pair encoding, the reproducibility of activation volume and LIs within the MTL tended to be worse compared to the fusiform and inferior frontal ROIs. The differences in FMRI reproducibility appeared more dependent on the task than the susceptibility effects. The results of this study suggest that FMRI-based assessment of the neural substrates of memory using a scene encoding task may be a useful clinical tool.