来自各种感觉方式的语音信息的处理对于人类交流至关重要。左后上颞回(pSTG)和运动皮层都重要参与多感官言语感知。然而,初级感觉区与pSTG和运动皮层的动态整合仍不清楚.这里,我们实施了经典McGurk效应范式的行为实验,并从63名正常成年人的同步视听音节感知中获取了任务功能磁共振成像(fMRI)数据.我们进行了动态因果模型(DCM)分析,以探索左pSTG之间的跨模态相互作用,左中前回(PrG),左颞上回(mSTG),左梭状回(FuG)。贝叶斯模型选择有利于一个获胜的模型,其中包括对PrG的连接调制(mSTG→PrG,FuG→PrG),从PrG(PrG→mSTG,PrG→FuG),和pSTG(mSTG→pSTG,FuG→pSTG)。此外,上述连接的耦合强度与行为McGurk易感性相关。此外,在强McGurk感知者和弱McGurk感知者之间,这些连接的耦合强度存在显着差异。强烈的感知者调节较少抑制视觉影响,允许较少的兴奋性听觉信息流入PrG,但在pSTG中集成了更多的视听信息。一起来看,我们的发现表明,在视听语音过程中,PrG和pSTG与初级皮层动态地相互作用,并支持运动皮层在调节听觉和视觉模态之间的增益和显着性方面发挥特定的功能作用。
■在线版本包含补充材料,可在10.1007/s11571-023-09945-z获得。
The processing of speech information from various sensory modalities is crucial for human communication. Both left posterior superior temporal gyrus (pSTG) and motor cortex importantly involve in the multisensory speech perception. However, the dynamic integration of primary sensory regions to pSTG and the motor cortex remain unclear. Here, we implemented a behavioral experiment of classical McGurk effect paradigm and acquired the task functional magnetic resonance imaging (fMRI) data during synchronized audiovisual syllabic perception from 63 normal adults. We conducted dynamic causal modeling (DCM) analysis to explore the cross-modal interactions among the left pSTG, left precentral gyrus (PrG), left middle superior temporal gyrus (mSTG), and left fusiform gyrus (FuG). Bayesian model selection favored a winning model that included modulations of connections to PrG (mSTG → PrG, FuG → PrG), from PrG (PrG → mSTG, PrG → FuG), and to pSTG (mSTG → pSTG, FuG → pSTG). Moreover, the coupling strength of the above connections correlated with behavioral McGurk susceptibility. In addition, significant differences were found in the coupling strength of these connections between strong and weak McGurk perceivers. Strong perceivers modulated less inhibitory visual influence, allowed less excitatory auditory information flowing into PrG, but integrated more audiovisual information in pSTG. Taken together, our findings show that the PrG and pSTG interact dynamically with primary cortices during audiovisual speech, and support the motor cortex plays a specifically functional role in modulating the gain and salience between auditory and visual modalities.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s11571-023-09945-z.