Audio-visual synchrony and spatial attention enhance processing of dynamic visual stimulation independently and in parallel: A frequency-tagging study
Audio-visual synchrony and spatial attention enhance processing of dynamic visual stimulation independently and in parallel: A frequency-tagging study
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DOI：
10.1016/j.neuroimage.2017.08.022
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发表时间：
2017-11-01
期刊：
影响因子：
5.7
通讯作者：
Mueller, Matthias M.
中科院分区：
文献类型：
--
作者：
Covic, Amra;Keitel, Christian;Mueller, Matthias M.
神经对视觉刺激的处理可以通过注意其位置或通过共同出现的听觉音调来促进。使用频率标记，我们调查是否促进空间注意和视听同步依赖于类似的神经过程。参与者注意到两个闪烁的Gabor补丁（14.17和17 Hz）位于相对的较低的视野之一。伽柏斑块进一步以不同的速率（3.14和3.63 Hz）“脉冲”（即显示平滑的空间频率变化）。以其中一个视觉刺激的脉冲速率对听觉刺激进行频率调制，建立了视听同步。闪烁和脉冲刺激引起刺激锁定的节律性电生理脑反应，允许跟踪神经处理的同时提出的伽柏补丁。这些稳态反应（SSR）在频谱域中进行量化，以检查视觉刺激处理的条件下，同步与异步的音调呈现，当相应的刺激位置被出席与无人值守。引人注目的是，脉冲和闪烁驱动的SSR的独特模式的影响表明，空间注意力和视听同步促进早期视觉处理并行，并通过不同的皮层过程。我们发现注意力效应类似于经典的自上而下的增益效应，促进了闪烁和脉冲驱动的SSR。视听同步，反过来，只放大同步产生的刺激方面（即脉冲驱动的SSR）可能突出的作用，时间共同发生的景象和声音在自下而上的多感官整合。
The neural processing of a visual stimulus can be facilitated by attending to its position or by a co-occurring auditory tone. Using frequency-tagging, we investigated whether facilitation by spatial attention and audiovisual synchrony rely on similar neural processes. Participants attended to one of two flickering Gabor patches (14.17 and 17 Hz) located in opposite lower visual fields. Gabor patches further "pulsed" (i.e. showed smooth spatial frequency variations) at distinct rates (3.14 and 3.63 Hz). Frequency-modulating an auditory stimulus at the pulse-rate of one of the visual stimuli established audio-visual synchrony. Flicker and pulsed stimulation elicited stimulus-locked rhythmic electrophysiological brain responses that allowed tracking the neural processing of simultaneously presented Gabor patches. These steady-state responses (SSRs) were quantified in the spectral domain to examine visual stimulus processing under conditions of synchronous vs. asynchronous tone presentation and when respective stimulus positions were attended vs. unattended. Strikingly, unique patterns of effects on pulse-and flicker driven SSRs indicated that spatial attention and audiovisual synchrony facilitated early visual processing in parallel and via different cortical processes. We found attention effects to resemble the classical top-down gain effect facilitating both, flicker and pulse-driven SSRs. Audio-visual synchrony, in turn, only amplified synchrony-producing stimulus aspects (i.e. pulse-driven SSRs) possibly highlighting the role of temporally co-occurring sights and sounds in bottom-up multisensory integration.