Single-Unit Activity during Natural Vision: Diversity, Consistency, and Spatial Sensitivity among AF Face Patch Neurons
Single-Unit Activity during Natural Vision: Diversity, Consistency, and Spatial Sensitivity among AF Face Patch Neurons
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DOI：
10.1523/jneurosci.3825-14.2015
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发表时间：
2015-04-08
影响因子：
5.3
通讯作者：
Leopold, David A.
中科院分区：
文献类型：
--
作者：
McMahon, David B. T.;Russ, Brian E.;Leopold, David A.
猕猴大脑STS内的几个视觉区域对人脸和其他生物刺激反应强烈。确定控制该区域神经反应的原理已被证明具有挑战性，部分原因是动态生物刺激固有的复杂刺激域无法被容易参数化的刺激集捕获。在这里，我们研究了当猕猴自由观看富含自然社交内容的复杂视频时，STS前眼底（AF）一个fmri定义的面部贴片的神经反应。纵向单单元记录允许每个神经元对重复视频演示的反应累积。我们发现单个神经元，虽然它们的反应模式不同，但始终如一地受到视频内容的决定性驱动。我们使用主成分分析来计算一个特征神经元家族，它总结了前两个成分中共享种群活动的24%。我们发现AF活动最突出的组成部分反映了可见身体区域和场景布局之间的相互作用。脸部特写引起最强的神经反应，而远处的脸部或臀部特写引起较弱或抑制反应。在伽马波段局部场电位中也观察到对表面接近的敏感性。这种对空间尺度的类别选择敏感性，以及已知的该区域与涉及视觉空间分析的区域的解剖投影交换，表明AF面部贴片可能专门用于与社交场景布局有关的面部感知方面。
Several visual areas within the STS of the macaque brain respond strongly to faces and other biological stimuli. Determining the principles that govern neural responses in this region has proven challenging, due in part to the inherently complex stimulus domain of dynamic biological stimuli that are not captured by an easily parameterized stimulus set. Here we investigated neural responses in one fMRI-defined face patch in the anterior fundus (AF) of the STS while macaques freely view complex videos rich with natural social content. Longitudinal single-unit recordings allowed for the accumulation of each neuron's responses to repeated video presentations across sessions. We found that individual neurons, while diverse in their response patterns, were consistently and deterministically driven by the video content. We used principal component analysis to compute a family of eigenneurons, which summarized 24% of the shared population activity in the first two components. We found that the most prominent component of AF activity reflected an interaction between visible body region and scene layout. Close-up shots of faces elicited the strongest neural responses, whereas far away shots of faces or close-up shots of hindquarters elicited weak or inhibitory responses. Sensitivity to the apparent proximity of faces was also observed in gamma band local field potential. This category-selective sensitivity to spatial scale, together with the known exchange of anatomical projections of this area with regions involved in visuospatial analysis, suggests that the AF face patch may be specialized in aspects of face perception that pertain to the layout of a social scene.