Time matters: Feature-specific prioritization follows feature integration in visual object processing
Time matters: Feature-specific prioritization follows feature integration in visual object processing
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DOI：
10.1016/j.neuroimage.2019.04.023
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发表时间：
2019-08-01
期刊：
影响因子：
5.7
通讯作者：
Mueller, Matthias M.
中科院分区：
文献类型：
--
作者：
Brummerloh, Berit;Mueller, Matthias M.
物体代表视觉注意力的基本选择单位。然而，与综合竞争解释不同的是，我们最近的研究表明，组成特征的注意促进不会自动在一个物体内传播，而是取决于每个特征的特定任务相关性。在这里，我们采用了一种新颖的实验设计，允许同时电生理测量在试探性和块状线索注意力转移过程中一个物体(正方形)内两个不同特征(旋转和颜色)的注意力分配。这是可能的，通过呈现一个正方形，分别唤起它的旋转和颜色变化的两个不同的稳态视觉诱发电位(SSVEP)。鉴于SSVEP的持续振荡性质，我们能够研究当受试者注意到这两个特征中的一个时，与注意整个物体时相比，人类大脑皮层早期视觉皮质中神经活动的时间进程。这种方法使我们能够揭示一个物体内基于特征的注意机制，以及它们与基于对象的机制的交互作用。行为学和电生理学结果都表明，这是一个两阶段的过程，包括组成对象特征的早期瞬时整合，随后是伴随着要注意的特征的放大的特征选择的持续机制，然后是时间上的对要忽略的特征的抑制。
Objects represent a fundamental selection unit of visual attention. However, at odds with the integrated competition account, our recent study demonstrated that attentional facilitation of constituent features does not spread automatically within an object, but instead depends on the specific task relevance of each feature. Here, we employed a novel experimental design, allowing simultaneous electrophysiological measurements of the allocation of attention to two distinct features (rotation and color) within one object (a square) during both trial-wise and block-wise cued shifts of attention. This was possible through the presentation of a square that evokes two distinct steady-state visual evoked potentials (SSVEPs) for its rotation and its color changes, respectively. Given the continuous oscillatory nature of SSVEPs, we were able to investigate the time course of neural activity in the early visual cortex of the human brain when subjects attended to one of the two features, compared to when the whole object was attended. This approach enabled us to uncover feature-based mechanisms of attention within one object, as well as their interaction with object-based mechanisms. Both behavioral and electrophysiological results indicate a biphasic process composed of an early transient integration of the constituent object features, followed by sustained mechanisms of feature selection with amplification of the to-be-attended feature, followed temporally by suppression of the to-be-ignored feature.