注意调节听感觉门控的神经机制以及双语经验的影响

Prepulse inhibition (PPI) is considered as a measurement of sensory gating, reflecting the function of early auditory sensory information selection. Although the main neural correlates of PPI lie in the brainstem, previous researches have found that PPI could be top-down modulated by attention. However, different forms of attention, such as feature-based attention and spatial attention, have not been investigated together in the specific modulation of PPI. Moreover, the neural mechanism of attentional modulation of PPI in humans has been focused on the cortical level, while the subcortical mechanism has remained unclear. Also, bilingual experience could enhance the attention and inhibition function, but the effect of bilingual experience on sensory gating remains unclear. The present project aims to use behavioral testing, electroencephalogram recording and functional magnetic resonance imaging, in order to investigate the various levels of neural representations of attentional modulation of PPI in the auditory system and the effect of bilingual experience. The project will 1) establish the behavioral paradigm of feature-based attentional and spatially attentional modulation of PPI, and examine the temporal dynamic processing differences between feature-based attentional modulation and spatially attentional modulation of PPI; 2) using brainstem frequency following responses (FFRs) to examine the subcortical neural mechanism of two types of attentional modulation of PPI, focusing on the envelope and fine structure processing differences of prepulse stimuli in the two types of attentional PPI modulation; 3) the key brain areas and neural networks involved in feature-based attentional modulation and spatially attentional modulation of PPI; 4) the effect of bilingual experience on PPI and attentional modulation of PPI, as well as the underlying cortical and subcortical mechanism. This project will not only improve our understanding of the neural mechanism underlying attentional modulation of sensory gating, but also shed light on the application of psychiatric disorders and artificial intelligence.

前脉冲抑制（PPI）是听感觉门控的测量模型，反映了听觉系统对早期感觉信息的选择性加工能力。尽管PPI的主要神经环路位于脑干，PPI仍可以被注意自上而下调节。然而，已有研究并未区分不同注意（特征注意和空间注意）对PPI的特异性调节，并且神经机制研究集中于听皮层区域，皮层下机制的探讨仍缺乏。此外，双语经验可以增强注意和抑制功能，但对感觉门控功能的影响仍不清楚。本项目将在以往研究和本人前期成果基础上，采用行为测量、脑电和脑成像技术，揭示两种注意调节PPI的神经活动在听觉系统中的层次性表达及双语的影响。研究包括1）建立特征注意和空间注意调节PPI的统一行为模型，考察两种注意调节PPI的时间动态性；2）两种注意调节PPI的脑干分离机制，即前脉冲刺激包络和精细结构成分加工在注意调节PPI中的作用差异；3）两种注意调节PPI的关键脑区和脑网络差异；4）双语经验对PPI及注意调节PPI的影响及神经机制。本项目不仅可以推动对高层注意调节底层感觉门控神经机制的理解，研究结果也将在精神医学和人工智能方面有实际应用价值。

前脉冲抑制（PPI）是公认的听感觉门控的测量模型，反映了听觉系统的早期信息选择功能。尽管PPI的主要神经环路位于脑干，研究发现PPI可以被注意自上而下调节。本项目采用行为测量、脑电测量等技术，主要考察了注意调节PPI的行为和神经机制，第一，项目团队系统梳理了注意调节PPI的研究文献，并引入听觉加工的双通路模型，构建出了多种注意调节PPI的分析框架；第二，建立了注意调节PPI的行为模型，包括（1）新的特征注意调节PPI的行为模型，发现150ms窄带噪声可以作为前脉冲刺激，构建新的不同频率特征前脉冲刺激对PPI的调节模型；（2）不相关片段（BIC）作为前脉冲刺激引起的PPI行为模型，发现BIC可以作为前脉冲刺激引起PPI，并且受到双耳延迟的调节作用；第三，考察了注意调节PPI的神经相关物，发现不同注意调节PPI存在皮层水平（N1/P2）的分离；第四，考察了音乐训练对PPI的影响，音乐训练可以提高被试的双耳加工能力。综合来看，课题组已基本完成本项目研究计划，揭示了人类被试中注意调节PPI的行为和神经机制，为听觉双耳信息加工和听觉注意的研究提供了独特的视角。