Spatiotemporal characteristics of form analysis in the human visual cortex revealed by rapid event-related fMRI adaptation
Spatiotemporal characteristics of form analysis in the human visual cortex revealed by rapid event-related fMRI adaptation
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DOI：
10.1016/j.neuroimage.2005.06.017
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发表时间：
2005-11-01
期刊：
影响因子：
5.7
通讯作者：
Huberle, E
中科院分区：
文献类型：
--
作者：
Kourtzi, Z;Huberle, E
将局部元素整合为连贯的形式是理解视觉感知的核心。越来越多的证据表明，早期retinotopic和更高的枕颞区有助于整合当地的元素，以全球的形式。然而，在人类视觉皮层的形式分析的时空特性仍然在很大程度上未知。本研究的目的是调查形式分析在不同的空间（全球与本地结构）和时间（不同的刺激呈现率）尺度跨阶段的视觉分析（从VI到外侧枕叶复合体-枕叶）在人脑中。我们使用封闭的轮廓线渲染的Gabor元素和操纵的全局轮廓结构或局部Gabor元素的方向。我们的快速事件相关fMRI适应研究表明，轮廓整合和形式处理在早期视觉区是短暂的，并限制在其细胞的感受野的局部邻域内。相比之下，更高的视觉区域似乎以更持续的方式处理所感知的整体形式。最后，我们证明，这些时空性质的形式处理在视觉皮层调制的注意。对整体形式的关注维持了枕颞区的持续处理，而对局部元素的关注则增强了它们在早期视觉区的整合。这些研究结果提供了新的神经影像学证据的形式分析在不同的时空尺度在人类视觉领域和验证使用快速事件相关的功能磁共振成像适应调查处理在人类大脑的视觉分析的各个阶段。(c)2005年爱思唯尔公司All rights reserved.
The integration of local elements to coherent forms is at the core of understanding visual perception. Accumulating evidence suggests that both early retinotopic and higher occipitotemporal areas contribute to the integration of local elements to global forms. However, the spatiotemporal characteristics of form analysis in the human visual cortex remain largely unknown. The aim of this study was to investigate form analysis at different spatial (global vs. local structure) and temporal (different stimulus presentation rates) scales across stages of visual analysis (from VI to the lateral occipital complex-LOC) in the human brain. We used closed contours rendered by Gabor elements and manipulated either the global contour structure or the orientation of the local Gabor elements. Our rapid event-related fMRI adaptation studies suggest that contour integration and form processing in early visual areas is transient and limited within the local neighborhood of their cells' receptive field. In contrast, higher visual areas appear to process the perceived global form in a more sustained manner. Finally, we demonstrate that these spatiotemporal properties of form processing in the visual cortex are modulated by attention. Attention to the global form maintains sustained processing in occipitotemporal areas, whereas attention to local elements enhances their integration in early visual areas. These findings provide novel neuroimaging evidence for form analysis at different spatiotemporal scales across human visual areas and validate the use of rapid event-related fMRI adaptation for investigating processing across stages of visual analysis in the human brain. (c) 2005 Elsevier Inc. All rights reserved.