Simultaneous EEG and MEG recordings reveal vocal pitch elicited cortical gamma oscillations in young and older adults
Simultaneous EEG and MEG recordings reveal vocal pitch elicited cortical gamma oscillations in young and older adults
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DOI：
10.1016/j.neuroimage.2019.116253
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发表时间：
2020-01-01
期刊：
影响因子：
5.7
通讯作者：
Alain, Claude
中科院分区：
文献类型：
--
作者：
Ross, Bernhard;Tremblay, Kelly L.;Alain, Claude
起源于听性脑干的频率跟随反应代表了语音的音高轮廓，可以用头皮电极记录。脑磁图研究还显示，在元音刺激的基频（f（0））的高伽马振荡的皮质的贡献。因此，研究频率跟随反应的皮层成分可以提供关于音高信息在皮层水平上如何编码的见解。比较衰老如何影响不同的反应可能有助于揭示老年言语理解缺陷背后的神经机制。我们同时记录了EEG和MEG对音节/ba/的反应。MEG波束形成器分析将源定位在双侧听觉皮层和中脑中。时频分析表明，在106 Hz和138 Hz之间的皮层活动的音高轮廓的忠实代表。交叉相关显示的潜伏期为20毫秒。此外，刺激发作引起皮层40赫兹的反应。40 Hz和f（0）反应幅度在老年人中增加，并且在右半球更大。年龄效应和f（0）反应的偏侧性仅在MEG中明显，表明这两种效应都是皮质反应的特征。在比较了EEG和MEG中的f（0）和N1反应之后，我们估计大约三分之一的头皮记录的f（0）反应可能起源于皮层。我们将皮质f（0）反应的重要性归因于皮质神经元的精确计时，皮质神经元充当音高的时间敏感代码。
The frequency-following response with origin in the auditory brainstem represents the pitch contour of voice and can be recorded with electrodes from the scalp. MEG studies also revealed a cortical contribution to the high gamma oscillations at the fundamental frequency (f(0)) of a vowel stimulus. Therefore, studying the cortical component of the frequency-following response could provide insights into how pitch information is encoded at the cortical level. Comparing how aging affects the different responses may help to uncover the neural mechanisms underlying speech understanding deficits in older age. We simultaneously recorded EEG and MEG responses to the syllable /ba/. MEG beamformer analysis localized sources in bilateral auditory cortices and the midbrain. Time-frequency analysis showed a faithful representation of the pitch contour between 106 Hz and 138 Hz in the cortical activity. A cross-correlation revealed a latency of 20 ms. Furthermore, stimulus onsets elicited cortical 40-Hz responses. Both the 40-Hz and the f(0) response amplitudes increased in older age and were larger in the right hemisphere. The effects of aging and laterality of the f(0) response were evident in the MEG only, suggesting that both effects were characteristics of the cortical response. After comparing f(0) and N1 responses in EEG and MEG, we estimated that approximately one-third of the scalp-recorded f(0) response could be cortical in origin. We attributed the significance of the cortical f(0) response to the precise timing of cortical neurons that serve as a time-sensitive code for pitch.