Differences in selectivity to natural images in early visual areas (V1-V3).
Differences in selectivity to natural images in early visual areas (V1-V3).
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DOI：
10.1038/s41598-017-02569-4
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发表时间：
2017-05-26
影响因子：
4.6
通讯作者：
Andrews TJ
中科院分区：
文献类型：
--
作者：
Coggan DD;Allen LA;Farrar ORH;Gouws AD;Morland AB;Baker DH;Andrews TJ
腹侧视觉通路的高级区域对完整的物体比杂乱的物体反应更强烈。这项研究的目的是确定这种对物体的选择性是否出现在处理的早期阶段。使用视网膜定位图为每个参与者定义视觉区域（V1-V3）。然后，参与者观看了来自不同物体类别（瓶子、椅子、脸、房子、鞋子）的完整和混乱的图像，同时使用功能磁共振成像测量神经反应。我们使用混乱图像的基本原理是，它们包含与完整对象相同的低级属性，但缺乏自然图像特征的高阶特征组合。在所有区域，打乱图像的神经反应都比完整图像高。然而，与V1和V2相比，V3中完整图像和打乱图像之间的差异较小。接下来，我们测量了对不同对象类别的完整图像和打乱图像的空间响应模式。我们发现，与类别之间的相关性相比，类别内的相关性更高，无论是完整的还是混乱的图像，都显示出不同的反应模式。与打乱图像相比，完整图像在V3中反应的空间模式更明显，但在V1或V2中则没有。这些发现证明了V3中对自然图像的选择性的出现。
High-level regions of the ventral visual pathway respond more to intact objects compared to scrambled objects. The aim of this study was to determine if this selectivity for objects emerges at an earlier stage of processing. Visual areas (V1–V3) were defined for each participant using retinotopic mapping. Participants then viewed intact and scrambled images from different object categories (bottle, chair, face, house, shoe) while neural responses were measured using fMRI. Our rationale for using scrambled images is that they contain the same low-level properties as the intact objects, but lack the higher-order combinations of features that are characteristic of natural images. Neural responses were higher for scrambled than intact images in all regions. However, the difference between intact and scrambled images was smaller in V3 compared to V1 and V2. Next, we measured the spatial patterns of response to intact and scrambled images from different object categories. We found higher within-category compared to between category correlations for both intact and scrambled images demonstrating distinct patterns of response. Spatial patterns of response were more distinct for intact compared to scrambled images in V3, but not in V1 or V2. These findings demonstrate the emergence of selectivity to natural images in V3.