Catagorizing Parallel Human Auditory Pathways by Spatiotemporally Focused TMS

描述(申请人提供)：人脑以惊人的速度和轻松地解释复杂的声学环境。尽管在过去的几十年里，我们对声音处理的神经元基础的了解已经有了很大的进步，但人类大脑皮质听觉通路的平行功能组织仍然是难以捉摸的。这项建议旨在开发、测试和改进一种新的绘制平行听觉路径的实验方法，通过检查声音信息的空间(“哪里”)与身份(“什么”)的双路径理论模型。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个别区域的暂时性非侵入性失活(即“暂时性损害”)期间的行为测量。我们将利用解剖和功能MRI、EEG和脑磁图(MEG)来确定声音识别(“What”)和定位(“Where”)任务中大脑活动的位置和时间进程。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质的个别区域。这将使我们能够研究假设的平行听觉通路中时空聚焦的瞬时失活是否会导致行为效应的双重分离。我们将同时测量EEG和TMS，以研究不同听觉皮质区域的瞬时失活对听觉诱发反应的调制。这项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方法将解剖学上和时间上聚焦的干扰脉冲无创且完全安全地应用到人脑中。基于fMRI/MEG/EEG的组合，将从时空脑成像电影中获得解剖和时间干扰焦点。这种多模式方法使我们能够在皮质听觉通路的不同焦点测试瞬时失活的特定行为效应，提供了一种独特的方法来验证动物模型、人类损伤研究和神经成像研究提出的理论。我们的研究将有助于更好地理解人类大脑中参与声音信息处理的神经通路和电路。虽然我们目前的重点是基础研究，但更多地了解听觉感知的神经元基础最终可能有助于听力障碍和学习障碍的调查，以及助听器和假体的开发。 与公共健康相关：我们使用先进的大脑成像和行为方法来绘制人类平行的皮质听觉路径图，具体测试一个关于不同的“什么”和“哪里”流的假说。这项研究还可能推进对各种伴有听觉异常的疾病的研究。

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.