Multiple scales of organization for object selectivity in ventral visual cortex
Multiple scales of organization for object selectivity in ventral visual cortex
复制标题
DOI：
10.1016/j.neuroimage.2011.02.079
复制
发表时间：
2011-06-01
期刊：
影响因子：
5.7
通讯作者：
Op de Beeck, Hans P.
中科院分区：
文献类型：
--
作者：
Brants, Marijke;Baeck, Annelies;Op de Beeck, Hans P.
对象知识是分层的。有几种假说认为，这种特性可能反映在腹侧视皮层的空间组织中。例如，一个类别的所有样本可能激活相同的皮层区域，但每个区域中激活峰值的位置略有不同。根据这一观点，类别选择性将在更大的空间尺度上进行组织，而不是样本选择性。从人类受试者的实验中，没有经验证据支持这种建议。在这里，我们用两种方法比较了两个数据集中类别和样本选择性的相对组织规模：（i）通过调查先前报道的fMRI数据的空间平滑对多体素选择性模式的可靠性的有益影响;（ii）通过比较这些选择性模式的空间频谱中较低和较高空间频率的相对权重。研究结果是一致的建议，选择性的刺激属性，对象之间的细微差别的基础上组织在一个更精细的规模比选择性的刺激属性，区分类别。这一发现证实了腹侧视觉通路中存在多尺度的组织。(C)2011 Elsevier Inc. All rights reserved.
Object knowledge is hierarchical. Several hypotheses have proposed that this property might be reflected in the spatial organization of ventral visual cortex. For example, all exemplars of a category might activate the same patches of cortex, but with a slightly different position of the peak of activation in each patch. According to this view, category selectivity would be organized at a larger spatial scale compared to exemplar selectivity. No empirical evidence for such proposals is available from experiments with human subjects. Here, we compare the relative scale of organization for category and exemplar selectivity in two datasets with two methods: (i) by investigating the previously reported beneficial effect of spatial smoothing of the fMRI data on the reliability of multi-voxel selectivity patterns; and (ii) by comparing the relative weight of lower and higher spatial frequencies in the spatial frequency spectrum of these selectivity patterns. The findings are consistent with the proposal that selectivity for stimulus properties that underlie finer distinctions between objects is organized at a finer scale than selectivity for stimulus properties that differentiate categories. This finding confirms the existence of multiple scales of organization in the ventral visual pathway. (C) 2011 Elsevier Inc. All rights reserved.