Department of Psychology, Michigan State University, East Lansing, MI 48824, USA; Cognitive Science Program, Michigan State University, East Lansing, MI 48824, USA.
Department of Psychology, Michigan State University, East Lansing, MI 48824, USA; Cognitive Science Program, Michigan State University, East Lansing, MI 48824, USA; Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA.
Neuropsychologia. 2012 Oct;50(12):2916-2925. doi: 10.1016/j.neuropsychologia.2012.08.022. Epub 2012 Sep 4.
Humans can attend to different objects independent of their spatial locations. While selecting an object has been shown to modulate object processing in high-level visual areas in occipitotemporal cortex, where/how behavioral importance (i.e., priority) for objects is represented is unknown. Here we examined the patterns of distributed neural activity during an object-based selection task. We measured brain activity with functional magnetic resonance imaging (fMRI), while participants viewed two superimposed, dynamic objects (left- and right-pointing triangles) and were cued to attend to one of the triangle objects. Enhanced fMRI response was observed for the attention conditions compared to a neutral condition, but no significant difference was found in overall response amplitude between two attention conditions. By using multi-voxel pattern classification (MVPC), however, we were able to distinguish the neural patterns associated with attention to different objects in early visual cortex (V1 to hMT+) and lateral occipital complex (LOC). Furthermore, distinct multi-voxel patterns were also observed in frontal and parietal areas. Our results demonstrate that object-based attention has a wide-spread modulation effect along the visual hierarchy and suggest that object-specific priority information is represented by patterned neural activity in the dorsal frontoparietal network.
人类可以独立于物体的空间位置关注不同的物体。虽然选择一个物体已经被证明可以调节枕颞叶皮质中高级视觉区域的物体处理，但物体的行为重要性（即优先级）是如何在何处表示的尚不清楚。在这里，我们检查了基于对象的选择任务期间分布式神经活动的模式。我们使用功能磁共振成像 (fMRI) 测量大脑活动，同时参与者观看两个叠加的动态物体（向左和向右的三角形），并被提示关注其中一个三角形物体。与中性条件相比，注意条件下观察到增强的 fMRI 反应，但在两个注意条件之间，总体反应幅度没有发现显著差异。然而，通过使用多体素模式分类 (MVPC)，我们能够区分与早期视觉皮层 (V1 到 hMT+) 和外侧枕叶复合体 (LOC) 中不同物体的注意力相关的神经模式。此外，在前额和顶叶区域也观察到了不同的多体素模式。我们的结果表明，基于对象的注意力在视觉层次结构中具有广泛的调制效应，并表明特定于对象的优先级信息由背侧额顶网络中的模式化神经活动表示。
