每周论坛之十五（总第287期）：陈骐（华南师范大学），2021年12月27日下午

每周论坛之十五（总第287期）

报告人：陈骐 教授

报告人单位： 华南师范大学心理学院

题目：Attentional templates as the neural interface between top-down attention and bottom-up sensory inputs

时间：2021年12月27日（周一，14:20-17:30）

地点：中山大学东校园心理学系（南学院楼C座）305

报告摘要：

Top-down attention prioritizes the selection of goal-related sensory evidence, and is well manifested as increased pre-stimulus baseline activity. Attentional templates carry concrete internal sensory representations of the attended objects/features, and have been found during the pre-stimulus period as well. It remains poorly understood, however, whether the top-down attention signal and the attentional template are the same or temporally dissociable neural processes. To answer this question in the present electroencephalogram (EEG) study on human subjects, we manipulated sustained top-down attention, emphasizing either perceptual grouping or segregation,  in the bistable Ternus display. A striking pattern of temporal dissociation was revealed between the top-down attentional signal and the attentional template. The top-down attentional signals gated the temporal window of perceptual grouping by regulating the pre-stimulus alpha frequency according to the current task demands. However, via time-resolved decoding analysis, we found that the pre-stimulus attentional signals did not carry representational information of the preferred percepts. Rather, the temporal generalization analysis revealed that concrete attentional templates of the preferred percepts were formulated only when the top-down attentional signal met the very first (and even still ambiguous) sign of bottom-up sensory inputs. Taken together, the present study provides novel evidence on how sustained top-down attention achieves its facilitatory role. Although the pre-stimulus attentional signal voluntarily gates attentional preferences, it does not carry representational information of the preferred percepts. Rather, concrete attentional templates are induced only upon the first interfacing between top-down attention and bottom-up sensory inputs, to eventually bias subjective perception towards the preferred percepts.

报告人简介：

陈骐，华南师范大学心理学院，二级教授、博士生导师。主要利用心理物理法、虚拟现实、眼动、功能磁共振成像、脑电和立体定向脑电等技术研究人类空间注意和跨通道选择性注意的认知神经机制。在PLOS Biology, Journal of Neuroscience, Cerebral Cortex等神经科学领域高水平期刊上发表SCI论文40余篇，主持多项国家级和省部级项目，曾获得全国百篇优博。