University of Applied Sciences Western Switzerland (HES-SO Valais).
University Hospital Centre and University of Lausanne.
J Cogn Neurosci. 2019 Mar;31(3):412-430. doi: 10.1162/jocn_a_01360. Epub 2018 Dec 4.
In real-world environments, information is typically multisensory, and objects are a primary unit of information processing. Object recognition and action necessitate attentional selection of task-relevant from among task-irrelevant objects. However, the brain and cognitive mechanisms governing these processes remain not well understood. Here, we demonstrate that attentional selection of visual objects is controlled by integrated top-down audiovisual object representations ("attentional templates") while revealing a new brain mechanism through which they can operate. In multistimulus (visual) arrays, attentional selection of objects in humans and animal models is traditionally quantified via "the N2pc component": spatially selective enhancements of neural processing of objects within ventral visual cortices at approximately 150-300 msec poststimulus. In our adaptation of Folk et al.'s [Folk, C. L., Remington, R. W., & Johnston, J. C. Involuntary covert orienting is contingent on attentional control settings. Journal of Experimental Psychology: Human Perception and Performance, 18, 1030-1044, 1992] spatial cueing paradigm, visual cues elicited weaker behavioral attention capture and an attenuated N2pc during audiovisual versus visual search. To provide direct evidence for the brain, and so, cognitive, mechanisms underlying top-down control in multisensory search, we analyzed global features of the electrical field at the scalp across our N2pcs. In the N2pc time window (170-270 msec), color cues elicited brain responses differing in strength and their topography. This latter finding is indicative of changes in active brain sources. Thus, in multisensory environments, attentional selection is controlled via integrated top-down object representations, and so not only by separate sensory-specific top-down feature templates (as suggested by traditional N2pc analyses). We discuss how the electrical neuroimaging approach can aid research on top-down attentional control in naturalistic, multisensory settings and on other neurocognitive functions in the growing area of real-world neuroscience.
在真实环境中，信息通常是多感官的，而物体是信息处理的主要单位。物体识别和行动需要注意力从无关任务的物体中选择与任务相关的物体。然而，大脑和认知机制仍然没有很好地理解这些过程。在这里，我们证明视觉物体的注意力选择是由集成的自上而下的视听物体表示（“注意力模板”）控制的，同时揭示了一种新的大脑机制，通过该机制可以操作它们。在多刺激（视觉）阵列中，人类和动物模型中物体的注意力选择传统上通过“N2pc 成分”来量化：在刺激后大约 150-300 毫秒，腹侧视觉皮层中物体的神经处理的空间选择性增强。在我们对 Folk 等人的 [Folk, C. L., Remington, R. W., & Johnston, J. C. 无意识的隐蔽定向是由注意控制设置决定的。实验心理学杂志：人类感知与表现，18, 1030-1044, 1992] 空间提示范式的改编中，与视觉搜索相比，视觉提示在视听搜索中引起较弱的行为注意力捕获和减弱的 N2pc。为了提供大脑和认知机制的直接证据，因此，在多感官搜索中的自上而下控制，我们分析了头皮上的电场的全局特征，跨越了我们的 N2pc。在 N2pc 时间窗口（170-270 毫秒）中，颜色提示引起了强度和拓扑不同的大脑反应。这后一个发现表明主动大脑源发生了变化。因此，在多感官环境中，注意力选择是通过集成的自上而下的物体表示来控制的，而不仅仅是通过传统 N2pc 分析所建议的单独的感觉特定的自上而下的特征模板。我们讨论了电神经影像学方法如何有助于在自然的、多感官的环境中进行自上而下的注意力控制研究，以及在日益增长的现实世界神经科学领域中的其他神经认知功能研究。
