Spatial vs. object specific attention in high-order visual areas
Spatial vs. object specific attention in high-order visual areas
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DOI：
10.1016/s1053-8119(03)00092-2
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发表时间：
2003-06-01
期刊：
影响因子：
5.7
通讯作者：
Malach, R
中科院分区：
文献类型：
--
作者：
Avidan, G;Levy, I;Malach, R
近期我们报道，人类视皮层中视野离心率的地形组织延伸至高级的枕颞腹侧（VOT）皮层。在该皮层内，对面部和建筑物优先做出反应的区域具有特定的离心率偏向，这表明这种类别 - 离心率关联可能反映了识别过程的不同需求。然而，尚不清楚高级枕颞皮层内的这种中心/周边分化在多大程度上取决于即时的、每时每刻的任务需求。先前的注意力研究要么局限于探索视野地形（空间注意力），要么局限于物体身份（基于物体的注意力）。在此，我们在同一研究中结合了对这两种不同注意力机制的研究。我们发现枕颞皮层中注意力调节的主要来源是基于物体的注意力。将注意力转移到不同的物体类别（建筑物、面部和箭头）极大地调节了与物体相关的激活。即使当注意力集中在不同的空间位置时，枕颞物体区域中对每个物体类别的差异激活仍然存在，尽管程度有所降低。在更靠背侧的枕叶外侧区域观察到了轻微的与离心率相关的注意力分化，但在VOT皮层中未观察到。这些结果反驳了VOT皮层中离心率分化的来源仅仅是由于空间注意力机制的每时每刻的变化这一可能性，并支持了在该区域发现的具有离心率偏向的图谱是由于长期过程中建立的内在形状选择性这一观点。（C）2003年爱思唯尔科学（美国）。保留所有权利。
Recently we reported that the topographic organization of visual field eccentricity in human visual cortex extends into high-order, ventral occipitotemporal (VOT) cortex. Within this cortex, regions that respond preferentially to faces and buildings have specific eccentricity biases, suggesting that this category-eccentricity association may reflect differential needs of recognition processes. However, it is still not clear to what extent this center/periphery differentiation within high-order occipitotemporal cortex depends on immediate, moment-to-moment, task demands. Previous attention studies were confined either to exploring the visual field topography (spatial attention) or to object identity (object-based attention). Here, we combined the investigation of these two different attentional mechanisms in the same study. We found that the main source of attentional modulation in occipitotemporal cortex was object-based attention. Shifting attention to different object categories (buildings, faces, and arrows) substantially modulated the object-related activations. The differential activation to each object category in occipitotemporal object areas was maintained, albeit at a reduced level, even when attention was focused on different spatial locations. A slight eccentricity-related attentional differentiation was observed in the more dorsal lateral occipital region, but not in the VOT cortex. These results argue against the possibility that the source of the eccentricity differentiation in VOT cortex is due solely, to moment-to-moment shifts in spatial attention mechanism and supports the notion that the eccentricity-biased maps found in this region are due to built-in shape selectivity established over long-term processes. (C) 2003 Elsevier Science (USA). All rights reserved.