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最显著的例子之一。虽然许多研究都集中在阐明功能差异上，但侧边性的确切潜在机制仍然未知。语言功能严重受损的是左半球，而不是右半球，而右半球损伤则会影响韵律的处理。许多人类和动物模型的研究都显示出类似的功能不对称，然而，语言半球偏侧的确切神经元机制仍然未知。已经提出了几种解释功能不对称的假设，包括不同的半球时间和光谱分辨率的能力，信息整合的时间尺度的差异，以及刺激的整体与局部处理的差异。本研究的目的是

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. !