Multivoxel pattern analysis reveals increased memory targeting and reduced use of retrieved details during single-agenda source monitoring.
Multivoxel pattern analysis reveals increased memory targeting and reduced use of retrieved details during single-agenda source monitoring.
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DOI：
10.1523/jneurosci.3587-08.2009
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发表时间：
2009-01-14
期刊：
影响因子：
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通讯作者：
Norman KA
中科院分区：
文献类型：
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作者：
McDuff SG;Frankel HC;Norman KA
我们使用功能磁共振成像数据的多体素模式分析（MVPA）来深入了解受试者的提取议程如何影响源记忆判断（项目X使用源Y研究？）。在实验1中，我们使用了一个单一的议程测试，受试者判断项目是否与目标源或没有研究。在实验2中，我们使用了一个多议程测试，受试者判断项目是否使用目标源研究，使用不同的源研究，或nonstudied。为了评估单议程和多议程源监测之间的差异，我们训练了一个分类器来检测研究中的源特异性fMRI活动，然后我们将分类器应用于测试阶段的数据。我们专注于目标源和实际源不同的试验，因此我们可以使用MVPA来跟踪与目标源和实际源相关的神经活动。我们的研究结果表明，单一议程监测与增加对目标源的关注（如增加的目标源活动，相对于基线）和减少使用与实际的，非目标源的信息。在多议程实验中，高水平的实际来源活动与正确拒绝的增加有关，这表明受试者正在使用对实际来源信息的回忆来避免来源记忆错误。在单一议程实验中，存在类似水平的实际来源活动（表明回忆正在发生），但实际来源活动与行为之间的关系并不存在（表明受试者未能正确利用这些信息）。
We used multi-voxel pattern analysis (MVPA) of fMRI data to gain insight into how subjects’ retrieval agendas influence source memory judgments (was item X studied using source Y?). In Experiment 1, we used a single-agenda test where subjects judged whether items were studied with the targeted source or not. In Experiment 2, we used a multi-agenda test where subjects judged whether items were studied using the targeted source, studied using a different source, or nonstudied. To evaluate the differences between single- and multi-agenda source monitoring, we trained a classifier to detect source-specific fMRI activity at study, and then we applied the classifier to data from the test phase. We focused on trials where the targeted source and the actual source differed, so we could use MVPA to track neural activity associated with both the targeted source and the actual source. Our results indicate that single-agenda monitoring was associated with increased focus on the targeted source (as evidenced by increased targeted-source activity, relative to baseline) and reduced use of information relating to the actual, non-target source. In the multi-agenda experiment, high-levels of actual-source activity were associated with increased correct rejections, suggesting that subjects were using recollection of actual-source information to avoid source memory errors. In the single-agenda experiment, there were comparable levels of actual-source activity (suggesting that recollection was taking place), but the relationship between actual-source activity and behavior was absent (suggesting that subjects were failing to make proper use of this information).