Attentional Selection of Feature Conjunctions Is Accomplished by Parallel and Independent Selection of Single Features
Attentional Selection of Feature Conjunctions Is Accomplished by Parallel and Independent Selection of Single Features
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DOI：
10.1523/jneurosci.5268-14.2015
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发表时间：
2015-07-08
影响因子：
5.3
通讯作者：
Hillyard, Steven A.
中科院分区：
文献类型：
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作者：
Andersen, Soren K.;Mueller, Matthias M.;Hillyard, Steven A.
研究基于特征的注意的实验通常考察了基于单一特征(例如，红色)进行选择的情况。然而，在更复杂的情况下，相关刺激可能不是通过单一的定义属性而是通过特定的特征组合来与其他刺激区分开来的。在这里，我们考察了由颜色和方向的连接定义的刺激的持续注意选择。人类观察者注意到每四个同时呈现的随机移动的水平或垂直红色或蓝色条的叠加场中的一个，以检测短暂的连贯运动间隔。通过记录每个闪烁刺激区域诱发的稳态视觉诱发电位(SSVEP)来评估早期视皮层的选择性刺激处理。我们直接对比了单个特征和特征连词的注意选择，发现在仅基于单个特征(颜色或方向)选择的条件下，SSVEP的幅度准确地预测了当注意到这两个特征的连词时SSVEP的注意增强的幅度。此外，在所有情况下，由有意识刺激引起的SSVEP幅度的增加伴随着由无人注意的刺激引起的SSVEP幅度的同等降低。我们的结论是，在早期视觉皮层中，特征-联合刺激的注意选择是通过其组成特征维度的平行和独立易化来完成的。
Experiments that study feature-based attention have often examined situations in which selection is based on a single feature (e. g., the color red). However, in more complex situations relevant stimuli may not be set apart from other stimuli by a single defining property but by a specific combination of features. Here, we examined sustained attentional selection of stimuli defined by conjunctions of color and orientation. Humanobservers attended to one out of four concurrently presented superimposed fields of randomly moving horizontal or vertical bars of red or blue color to detect brief intervals of coherent motion. Selective stimulus processing in early visual cortex was assessed by recordings of steady-state visual evoked potentials (SSVEPs) elicited by each of the flickering fields of stimuli. We directly contrasted attentional selection of single features and feature conjunctions and found that SSVEP amplitudes on conditions in which selection was based on a single feature only (color or orientation) exactly predicted the magnitude of attentional enhancement of SSVEPs when attending to a conjunction of both features. Furthermore, enhanced SSVEP amplitudes elicited by attended stimuli were accompanied by equivalent reductions of SSVEP amplitudes elicited by unattended stimuli in all cases. We conclude that attentional selection of a feature-conjunction stimulus is accomplished by the parallel and independent facilitation of its constituent feature dimensions in early visual cortex.