The advantage of brief fMRI acquisition runs for multi-voxel pattern detection across runs
The advantage of brief fMRI acquisition runs for multi-voxel pattern detection across runs
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DOI：
10.1016/j.neuroimage.2012.03.076
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发表时间：
2012-07-16
期刊：
影响因子：
5.7
通讯作者：
Thompson-Schill, Sharon L.
中科院分区：
文献类型：
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作者：
Coutanche, Marc N.;Thompson-Schill, Sharon L.
功能磁共振成像(FMRI)研究被分成几个阶段(或“阶段”)，通常选择较长的时间，以最大限度地减少跨阶段的信号差异。然而，对于使用多体素模式分析(MVPA)的研究来说，采用许多较短的运行可能会提高分类器概括不相关的模式变化和检测与条件相关的活动模式的能力。我们通过扫描长时间和短时间的参与者，并使用每组运行的数据比较MVPA的表现，直接检验了这一假设。每一次运行都包括展示面孔、地点、人造物体和水果，采用模块化的1-Back设计。在具有相同数据量的跨运行分类中，与使用几个长运行相比，使用大量短运行显著提高了MVPA的性能。在所使用的分类器、特征选择程序和感兴趣区域的变化中发现了更好的分类。性能的改进也延伸到了信息大脑地图的“探照灯”程序。这些结果表明，希望最大限度地检测跨运行的微妙多体素模式的研究人员可能会考虑使用短时间的fMRI运行。(C)2012 Elsevier Inc.保留所有权利。
Functional magnetic resonance imaging (fMRI) studies are broken up into runs (or 'sessions'), frequently selected to be long to minimize across-run signal variations. For investigations that use multi-voxel pattern analysis (MVPA), however, employing many short runs might improve a classifier's ability to generalize across irrelevant pattern variations and detect condition-related activity patterns. We directly tested this hypothesis by scanning participants with both long and short runs and comparing MVPA performance using data from each set of runs. Every run included presentations of faces, places, man-made objects and fruit in a blocked 1-back design. MVPA performance significantly improved from using a large number of short runs, compared to several long runs, in across-run classifications with identical amounts of data. Superior classification was found across variations in the classifier employed, feature selection procedure and region of interest. Performance improvements also extended to an information brain mapping 'searchlight' procedure. These results suggest that investigators looking to maximize the detection of subtle multi-voxel patterns across runs might consider employing short fMRI runs. (C) 2012 Elsevier Inc. All rights reserved.