Catagorizing Parallel Human Auditory Pathways by Spatiotemporally Focused TMS

描述（由申请人提供）：人脑能够以惊人的速度和轻松地解读复杂的声音环境。虽然在过去的几十年里，我们对声音处理的神经元基础的理解有了很大的进步，但人脑皮层听觉通路的平行功能组织仍然是难以捉摸的。本提案旨在开发、测试和完善一种新的实验方法，通过检查声音信息的空间（“在哪里”）和身份（“什么”）双重路径的理论模型，来绘制平行听觉路径。我们的新方法结合了先进的时空脑成像技术和人类听觉通路单个区域短暂非侵入性失活（即“短暂损伤”）期间的行为测量。我们将利用解剖和功能MRI， EEG和脑磁图（MEG）来确定在声音识别（“什么”）和定位（“在哪里”）任务中大脑活动的位置和时间过程。经颅磁刺激（TMS）将被用来调节在任务执行过程中被激活的听觉皮层的单个区域。这将使我们能够研究在假定的平行听觉通路中，时空集中的短暂失活是否会导致行为效应的双重分离。我们将同时测量脑电图和经颅磁刺激，以研究听觉皮层不同区域的短暂失活对听觉诱发反应的调节。拟议的研究将使用先进的神经成像方法来研究人类大脑如何处理听觉信息。时空聚焦TMS方法将解剖和时间聚焦的干扰脉冲非侵入性和完全安全地应用于人脑。基于fMRI/MEG/EEG相结合的方法，从时空脑成像影像中获取干扰的解剖灶和时间灶。这种多模式方法使我们能够测试皮层听觉通路不同病灶的短暂失活的特定行为影响，为验证动物模型、人体病变研究和神经影像学研究提出的理论提供了一种独特的方法。我们的研究将有助于我们更好地理解人脑中处理声音信息的神经通路和电路。虽然我们目前的重点是基础研究，但对听觉感知神经元基础的更深入了解可能最终有利于听力障碍和学习障碍的研究，以及助听器和假肢的开发。

DESCRIPTION (provided by applicant): The human brain interprets complex acoustic environments with astounding speed and ease. Although our understanding on the neuronal basis of sound processing has greatly advanced during the past decades, the parallel functional organization of cortical auditory pathways of the human brain is still elusive. This proposal aims to develop, test, and refine a new experimental approach for mapping parallel auditory pathways, by examining a theoretical model of dual pathways for spatial ("where") vs. identity ("what") of sound information. Our novel approach combines advanced spatiotemporal brain imaging techniques and behavioral measurements during transient non-invasive deactivation (i.e., "transient lesions") of individual regions of human auditory pathway. We will utilize anatomical and functional MRI, EEG, and magnetoencephalography (MEG) to identify the locations and time courses of brain activity during sound identification ("what") and localization ("where") tasks. Transcranial magnetic stimulation (TMS) will be utilized to modulate individual regions of auditory cortex that are activated during task performance. This will allow us to investigate whether spatiotemporally focused transient deactivations in the putative parallel auditory pathways result in a double dissociation of behavioral effects. We will measure EEG simultaneously with TMS, to investigate modulation of auditory evoked responses by transient deactivation of different auditory cortex areas. The proposed studies will use advanced neuroimaging methods to study how the human brain processes auditory information. The spatiotemporally focused TMS approach applies anatomically and temporally focused interference pulses non-invasively and completely safely into the human brain. The anatomical and temporal foci of interference will be obtained from spatiotemporal brain imaging movies, based on combined fMRI/MEG/EEG. This multimodal approach allows us to test the specific behavioral effects of transient deactivation in the different foci of cortical auditory pathway, providing a unique way to verify theories suggested by animal models, human lesion studies, and neuroimaging research. Our research will lead to a better understanding of the neuronal pathways and circuits involved in the processing of sound information in the human brain. Although our current focus is in basic research, greater understanding of the neuronal basis of auditory perception may ultimately benefit investigation of hearing impairments and learning disabilities, as well as development of hearing aids and prosthetics. PUBLIC HEALTH RELEVANCE: We use advanced brain imaging and behavioral methods for mapping of parallel cortical auditory pathways in humans, by specifically testing a hypothesis of distinct "what" and "where" streams. This research may also advance investigation of various disorders with auditory abnormalities.