Top-down control during selective listening in cocktail party situations

在日常生活中，听者经常面临由多个独立音流组成的复杂听觉环境。有选择地听其中一个流，同时不被竞争的听觉刺激分散注意力，这对我们的听觉系统来说是一个终极挑战。先前的研究已经令人信服地证明，信息的注意过滤发生在听觉系统中不同层次的感觉处理中，导致听觉皮层对参与流的表征增加和对无关信息的抑制。自愿控制注意力集中和有选择地听任何感兴趣的声源的能力与大脑额叶和顶叶区域网络中的神经活动有关。然而，在选择性倾听过程中，这两种加工水平是如何相互作用的尚不完全清楚。因此，在加拿大蒙特利尔Robert Zatorre博士的实验室进行研究期间，我将研究选择性听力过程中，听觉皮层中信息的注意门控与额顶叶注意网络施加的自上而下目标导向控制之间的关系。脑磁图（MEG）将用于测量正常听众和一组训练有素的专业音乐家在选择性聆听任务期间的皮质活动。这些数据将在群体层面上进行分析，并使用基于表现的主体间方法来识别那些大脑区域和功能连接，这些区域和功能连接对于在具有挑战性的情况下成功地进行选择性倾听至关重要。第二步，将使用高分辨率结构磁共振成像（MRI）和扩散张量成像（DTI）研究卓越选择性听力能力的结构标记。

In daily life, listeners are often confronted with complex auditory environments consisting of multiple independent sound streams. Selectively listening to one of these streams, while not being distracted by the competing auditory stimulation, represents an ultimate challenge for our auditory system. Previous work has compellingly demonstrated that attentional filtering of information occurs at different levels of sensory processing within the auditory system, leading to both an increased auditory cortex representation of the attended stream and a suppression of irrelevant information. The ability to voluntarily control the focus of attention and to listen selectively to any sound source of interest has been linked to neural activity in a network of frontal and parietal brain regions. How these two processing levels interact during selective listening is however not fully understood. During my proposed research stay in the lab of Dr. Robert Zatorre in Montreal, Canada, I will therefore investigate the relationship between attentional gating of information in auditory cortex and goal-directed top-down control exerted by the fronto-parietal attention network during selective listening. Magnetoencephalography (MEG) will be used to measure cortical activity during a selective listening task in normal listeners as well as in a group of highly trained professional musicians. The data will be analyzed both on group-level and using performance-based between-subject approaches to identify those brain regions and functional connections essential for successful selective listening in challenging situations. In a second step, structural markers of superior selective listening abilities will be investigated using high resolution structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI).