Hemispheric asymmetry in auditory processing - spectral and temporal modulations

描述（由申请人提供）：语言处理仍然是半球不对称的最突出的例子之一。虽然许多研究都集中在阐明功能的差异，确切的潜在机制的偏侧性仍然未知。语言功能在左半球而不是右半球的病变中受到严重破坏，而右半球的损伤损害了韵律的处理。在人类和动物模型中的许多研究都显示了类似的功能不对称性，然而，语言中大脑半球侧化的确切神经机制仍然未知。已经提出了几个假设来解释功能不对称性，包括不同的半球的时间和光谱分辨率的能力，信息整合的时间尺度的差异，以及全球与本地处理的刺激。本研究的目的是 提出并检验一个统一的假设，即左半球处理大范围的时间调制和有限范围的频谱调制，而右半球处理大范围的频谱调制和有限范围的时间调制。使用新的刺激过滤技术，我们建议改变语音刺激的频谱调制和时间调制轴，并直接测试我们的假设，使用脑磁图（MEG）和皮层脑电图（ECoG）。具体而言，我们将解决：1）左右半球对频谱和时间调制的敏感性; 2）听觉皮层的任务相关调制; 3）高阶听觉皮层场中的频谱-时间听觉感受野。!

DESCRIPTION (provided by applicant): Language processing remains one of the most striking examples of hemispheric asymmetry. While much research has focused on elucidating the functional differences, the exact underlying mechanisms of the laterality remain unknown. Language function is severely disrupted in left but not right hemisphere lesions while damage to the right hemisphere impairs the processing of prosody. Many studies in both humans and animal models have exhibited similar functional asymmetries, nevertheless, the exact neuronal mechanisms underlying hemispheric lateralization in language remain unknown. Several hypotheses have been proposed explaining the functional asymmetries, including a differing hemispheric capacity for temporal and spectral resolution, a difference in the temporal scale of information integration as well as global vs. local processing of stimuli. The aim of this study is to propose and test a unifying hypothesis whereby the left hemisphere processes a wide range of temporal modulations and a limited range of spectral modulations and the right hemisphere processes a wide range of spectral modulations and a limited range of temporal modulations. Using novel stimuli filtering techniques, we propose altering speech stimuli on a spectral modulation and temporal modulation axis and directly test our hypothesis using Magnetoencephalography (MEG) and Electrocorticography (ECoG). Specifically, we will address: 1) Left and right hemisphere sensitivity to spectral and temporal modulations; 2) Task-related modulations of auditory cortex; 3) Spectrotemporal auditory receptive fields in higher order auditory cortical fields. !