Parietal activity in episodic retrieval measured by fMRI and MEG.
Parietal activity in episodic retrieval measured by fMRI and MEG.
复制标题
通过 fMRI 和 MEG 测量情景检索中的顶叶活动。
DOI：
10.1016/j.neuroimage.2010.11.078
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发表时间：
2011
期刊：
影响因子：
5.7
通讯作者：
Brewer,JamesB
中科院分区：
文献类型：
--
作者：
Seibert,TylerM;Gimbel,SarahI;HaglerJr,DonaldJ;Brewer,JamesB
要了解左侧顶叶皮质在情景提取中的功能作用，需要对记忆任务中活动的空间和时间特征进行表征。在最近的一项使用脑磁图(MEG)的研究中，我们描述了线索回忆任务中的早期顶叶反应。此响应在检索提示后100毫秒(Ms)内开始，持续时间不到400ms。在空间上，这种影响在研究中包括的所有三个解剖学定义的左侧顶叶亚区都达到了显著水平。在这里，我们提出了在相同的线索回忆范式下对血流动力学和电生理反应的多模式分析。功能磁共振成像(FMRI)被用来更准确地显示顶叶皮质反应最大的部分。然后重新分析脑磁图数据集，以显示功能磁共振确定的区域的早期脑磁图时间进程。我们发现，在顶沟内血流动力学反应最大。此外，该区域的脑磁图在提示取回后的最初300ms内显示出强烈的反应。最后，当分析早期300毫秒时间窗内左侧皮质表面的个体偶极子脑磁图活动时，重要的回忆相关活动仅限于左侧大脑半球相对较小的部分，该部分与顶内沟的功能磁共振成像识别的区域重叠。
Understanding the functional role of the left lateral parietal cortex in episodic retrieval requires characterization of both spatial and temporal features of activity during memory tasks. In a recent study using magnetoencephalography (MEG), we described an early parietal response in a cued-recall task. This response began within 100milliseconds (ms) of the retrieval cue and lasted less than 400ms. Spatially, the effect reached significance in all three anatomically defined left lateral parietal subregions included in the study. Here we present a multimodal analysis of both hemodynamic and electrophysiologic responses in the same cued-recall paradigm. Functional MRI (fMRI) was used to more precisely reveal the portion of the parietal cortex with the greatest response. The MEG data set was then reanalyzed to show the early MEG time course of the region identified by fMRI. We found that the hemodynamic response is greatest within the intraparietal sulcus. Further, the MEG pattern in this region shows a strong response during the first 300ms following the cue to retrieve. Finally, when individual-dipole MEG activity is analyzed for the left cortical surface over the early 300-millisecond time window, significant recall-related activity is limited to a relatively small portion of the left hemisphere that overlaps the region identified by fMRI in the intraparietal sulcus.