Functional magnetic resonance imaging investigation of overlapping lateral occipitotemporal activations using multi-voxel pattern analysis
Functional magnetic resonance imaging investigation of overlapping lateral occipitotemporal activations using multi-voxel pattern analysis
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DOI：
10.1523/jneurosci.3619-06.2007
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发表时间：
2007-01-03
影响因子：
5.3
通讯作者：
Peelen, Marius V.
中科院分区：
文献类型：
--
作者：
Downing, Paul E.;Wiggett, Alison J.;Peelen, Marius V.
几个功能区域被认为位于人类的外侧枕颞皮层，包括对运动有选择性的猕猴MT区的人类同源区域（hMT）、对物体形状有选择性的外侧枕叶复合体（LO）以及对身体有选择性的纹外体区（EBA）。事实上，一些功能性磁共振成像（fMRI）研究已经报道了这些区域之间存在显著的激活重叠。对这种重叠的标准解释是，激活的共同区域反映了共同神经系统的参与。或者，运动、物体形状和身体形状可能在这个大致区域内被独立处理。为了区分这些可能性，我们首先通过全脑组平均分析以及被试内感兴趣功能区域（ROI）分析，对外侧枕颞叶对运动、物体、身体和身体部位的反应进行了分析。在组分析中，这些刺激（相对于匹配的对照）所引发的激活有大量重叠。当在被试内对hMT、LO和EBA进行功能性定义时，每个半球的每个ROI（除了右半球的hMT）对运动、完整物体、身体和身体部位都表现出显著的选择性，尽管只测试了每个区域的峰值体素。相比之下，对选择性模式变化的多体素分析显示，视觉运动、物体形状和人体形状在外侧枕颞皮层引发了三种相对独立的fMRI活动模式。与其他方法相比，多体素方法能够揭示纹外皮层（进而延伸到大脑其他部位）中重叠的fMRI活动的功能意义。
Several functional areas are proposed to reside inhumanlateral occipitotemporal cortex, including the motion-selective human homolog of macaque area MT (hMT), object-form-selective lateral occipital complex (LO), and body-selective extrastriate body area (EBA). Indeed, several functional magnetic resonance imaging ( fMRI) studies have reported significant activation overlap among these regions. The standard interpretation of this overlap would be that the common areas of activation reflect engagement of common neural systems. Alternatively, motion, object form, and body form may be processed independently within this general region. To distinguish these possibilities, we first analyzed the lateral occipitotemporal responses to motion, objects, bodies, and body parts with whole-brain group-average analyses and within-subjects functional region of interest (ROI) analyses. The activations elicited by these stimuli, each relative to a matched control, overlapped substantially in the group analysis. When hMT, LO, and EBA were defined functionally within subjects, each ROI in each hemisphere (except right-hemisphere hMT) showed significant selectivity for motion, intact objects, bodies, and body parts, although only the peak voxel of each region was tested. In contrast, multi-voxel analyses of variations in selectivity patterns revealed that visual motion, object form, and the form of the human body elicited three relatively independent patterns of fMRI activity in lateral occipitotemporal cortex. Multi-voxel approaches, in contrast to other methods, can reveal the functional significance of overlapping fMRI activity in extrastriate cortex and, by extension, elsewhere in the brain.