Cortical dynamics of orientation and switching of non-spatial auditory attention

描述(由申请人提供)：在许多情况下，关注感兴趣的声音来源的能力对于口头交流是至关重要的。当多个说话者同时发言时，能够引导和重新定向注意力对于提取相关信息是必要的。然而，涉及引导听觉注意的神经处理还没有完全被理解。此外，确定自上而下的注意力控制如何与声源的自下而上的可区分性相互作用，为理解听力障碍如何影响有效的认知控制提供了关键的第一步；理解这个问题可以为助听器和人工耳蜗器改进编码算法的设计提供信息。以往在听觉和视觉方面的神经成像研究都表明，几种大脑皮层结构参与了利用空间信息进行的自愿注意转换，但使用非空间信息进行注意转换的机制和动力学尚不清楚。我们将在人类进行心理声学任务的行为和神经成像研究中，研究基于非空间刺激特征的听觉注意的定向和转换。为了捕捉皮质动力学，我们将使用多模式成像方法，结合磁学和脑电(M-EEG)提供的时间分辨率，同时使用解剖磁共振成像(MRI)扫描共同约束皮质激活的定位。我们的第一个目标是进行一系列心理物理实验，旨在考察基于非空间刺激特征的注意力切换的成本，作为竞争声音的外围可分割性的函数。我们的第二个目标是使用神经成像技术来研究基于非空间特征的注意切换的大脑皮层动力学。通过结合心理物理学和神经成像，我们将确定与听觉注意的定向和转换有关的皮质网络的时间动力学。这项研究将使我们能够更好地了解听觉系统如何使我们在具有挑战性的声学环境中进行有效的沟通。

DESCRIPTION (provided by applicant): The ability to pay attention to sound sources of interest is critical for verbal communication in many situations. When multiple talkers are speaking simultaneously, being able to direct and redirect attention is necessary to extract relevant information. However, the neural processing involved in directing auditory attention is not fully understood. Moreover, establishing how top-down control of attention interacts with the bottom-up differentiability of sound sources provides a critical first step in understanding how hearing deficits can impact effective cognitive control; understanding this issue could inform the design of improved coding algorithms for hearing aids and cochlear implants. Previous neuroimaging studies in both audition and vision have implicated the involvement of several cortical structures in the voluntary switching of attention using spatial information, but the mechanisms and dynamics of switching attention using non-spatial information are unknown. We will study orientation and switching of auditory attention based on non-spatial stimulus features in behavioral and neuroimaging studies of human subjects performing psychoacoustical tasks. To capture cortical dynamics, we will employ a multimodal imaging approach, combining the temporal resolution provided by magneto- and electro-encephalography (M-EEG) while co-constraining the localization of cortical activation using anatomical magnetic resonance imaging (MRI) scans. Our first aim is to perform a set of psychophysical experiments designed to examine the cost of switching attention based on non-spatial stimulus features as a function of the peripheral separability of competing sounds. Our second aim is to use neuroimaging techniques to examine the cortical dynamics of switching attention based on non-spatial features. By combining psychophysics and neuroimaging, we will determine the temporal dynamics of the cortical network involved in orientation and switching of auditory attention. This research will allow us to better understand how the auditory system enables us to communicate effectively in challenging acoustic environments.