On the Variability of the McGurk Effect: Audiovisual Integration Depends on Prestimulus Brain States
On the Variability of the McGurk Effect: Audiovisual Integration Depends on Prestimulus Brain States
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DOI：
10.1093/cercor/bhr125
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发表时间：
2012-01-01
期刊：
影响因子：
3.7
通讯作者：
Weisz, Nathan
中科院分区：
文献类型：
--
作者：
Keil, Julian;Mueller, Nadia;Weisz, Nathan
麦格克效应证明了视觉线索对听觉知觉的影响。来自两种感觉模式的不匹配信息可以融合成既不匹配听觉刺激也不匹配视觉刺激的新感知。据报道，这种错觉出现在60%-80%的试验中。我们感兴趣的是正在进行的大脑振荡--以波动的局部兴奋性和区域间同步为指标--对即将到来的对相同刺激的感知的影响。在感知麦格克效应之前，顶叶、额叶和颞叶区域会出现高β活动。左侧颞上回(LSTG)有明显的β活动，被认为是多模式整合的部位。在错觉试验中，这个区域在功能上(去)连接到分布的额区和颞区。当LSTG更强烈地耦合到额顶区域时，融合多感觉信息的倾向被增强。幻觉伴随着刺激后楔脑、楔前叶和左额上回的Theta带活动的减少。左侧颞中回的事件相关活动在幻觉过程中明显。因此，McGurk效应依赖于波动的大脑状态，这表明左侧ST在刺激前阶段的功能连接对视听感知至关重要。
The McGurk effect demonstrates the influence of visual cues on auditory perception. Mismatching information from both sensory modalities can fuse to a novel percept that matches neither the auditory nor the visual stimulus. This illusion is reported in 60-80% of trials. We were interested in the impact of ongoing brain oscillations-indexed by fluctuating local excitability and interareal synchronization-on upcoming perception of identical stimuli. The perception of the McGurk effect is preceded by high beta activity in parietal, frontal, and temporal areas. Beta activity is pronounced in the left superior temporal gyrus (lSTG), which is considered as a site of multimodal integration. This area is functionally (de)coupled to distributed frontal and temporal regions in illusion trials. The disposition to fuse multisensory information is enhanced as the lSTG is more strongly coupled to frontoparietal regions. Illusory perception is accompanied by a decrease in poststimulus theta-band activity in the cuneus, precuneus, and left superior frontal gyrus. Event-related activity in the left middle temporal gyrus is pronounced during illusory perception. Thus, the McGurk effect depends on fluctuating brain states suggesting that functional connectedness of left STS at a prestimulus stage is crucial for an audiovisual percept.