Feature-Selective Attentional Modulations in Human Frontoparietal Cortex
Feature-Selective Attentional Modulations in Human Frontoparietal Cortex
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DOI：
10.1523/jneurosci.3935-15.2016
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发表时间：
2016-08-03
影响因子：
5.3
通讯作者：
Awh, Edward
中科院分区：
文献类型：
--
作者：
Ester, Edward F.;Sutterer, David W.;Awh, Edward
对视觉选择的控制长期以来一直被认为是“来源”和“地点”之间的二分法，其中来自额顶叶皮层区域的自上而下的反馈信号调节或偏向后部视觉区域的感觉处理。这种区别部分是由于观察到额顶叶皮层区域编码任务水平变量（例如，什么刺激是当前相关的或什么运动输出是适当的），而后部感觉区域编码连续或模拟特征表示。在这里，我们提出的证据，挑战这种区别。我们使用功能磁共振成像，一个巡回探照灯分析，和一个倒置的编码模型来检查表示的基本特征属性（方向）在整个人类皮层片，而参与者出席的方向或亮度的周边光栅。方位选择性表征存在于大量的视觉、顶叶和前额叶皮层区域，包括内侧枕叶皮层、外侧顶叶皮层和上级中央前沟（被认为包含猕猴额叶眼区的人类同源物）。此外，在许多，但不是所有的这些地区的代表性更强，当参与者被指示出席方向相对于亮度。总的来说，这些研究结果挑战模型，证明简单的特征值是由整个视觉处理层次的皮层区域编码的，并且在许多这些领域的代表性调制的基础上，代表性的属性的注意力控制的来源和站点之间的严格隔离。
Control over visual selection has long been framed in terms of a dichotomy between "source" and "site," where top-down feedback signals originating in frontoparietal cortical areas modulate or bias sensory processing in posterior visual areas. This distinction is motivated in part by observations that frontoparietal cortical areas encode task-level variables (e.g., what stimulus is currently relevant or what motor outputs are appropriate), while posterior sensory areas encode continuous or analog feature representations. Here, we present evidence that challenges this distinction. We used fMRI, a roving searchlight analysis, and an inverted encoding model to examine representations of an elementary feature property (orientation) across the entire human cortical sheet while participants attended either the orientation or luminance of a peripheral grating. Orientation-selective representations were present in a multitude of visual, parietal, and prefrontal cortical areas, including portions of the medial occipital cortex, the lateral parietal cortex, and the superior precentral sulcus (thought to contain the human homolog of the macaque frontal eye fields). Additionally, representations in many-but not all-of these regions were stronger when participants were instructed to attend orientation relative to luminance. Collectively, these findings challenge models that posit a strict segregation between sources and sites of attentional control on the basis of representational properties by demonstrating that simple feature values are encoded by cortical regions throughout the visual processing hierarchy, and that representations in many of these areas are modulated by attention.