Aging Affects Neural Synchronization to Speech-Related Acoustic Modulations.
Aging Affects Neural Synchronization to Speech-Related Acoustic Modulations.
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DOI：
10.3389/fnagi.2016.00133
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发表时间：
2016
影响因子：
4.8
通讯作者：
van Wieringen A
中科院分区：
文献类型：
--
作者：
Goossens T;Vercammen C;Wouters J;van Wieringen A
随着人们年龄的增长，言语感知问题变得非常普遍，尤其是在嘈杂的环境中。除了外围听力和认知之外，时间处理在语音感知中也起着关键作用。语音特征的时间处理是由中枢听觉系统中神经振荡的同步活动介导的。先前的研究表明，同步神经活动的程度和半球偏侧化都与言语感知表现有关。基于这些结果，我们假设老年人言语感知受损可能部分源于神经同步的偏差。在这项研究中，在年轻、中年和老年人中记录了反映 theta、beta、低和高 gamma 振荡（分别为 4、20、40 和 80 Hz ASSR）同步活动的听觉稳态反应。由于所有参与者都有正常的听力阈值，并且接受了（轻度）认知障碍筛查，因此三个年龄组之间同步神经活动的差异可能归因于年龄。我们的数据得出了关于衰老听觉系统中的 θ 和高伽马振荡的新发现。在年龄较大时，θ 振荡的同步活动增加，而高伽马同步活动减少。与年轻人在处理高伽玛范围调制时表现出右半球优势相比，老年人表现出对称的处理模式。这些与年龄相关的神经同步变化很可能是老年人言语感知问题的根源。
As people age, speech perception problems become highly prevalent, especially in noisy situations. In addition to peripheral hearing and cognition, temporal processing plays a key role in speech perception. Temporal processing of speech features is mediated by synchronized activity of neural oscillations in the central auditory system. Previous studies indicate that both the degree and hemispheric lateralization of synchronized neural activity relate to speech perception performance. Based on these results, we hypothesize that impaired speech perception in older persons may, in part, originate from deviances in neural synchronization. In this study, auditory steady-state responses that reflect synchronized activity of theta, beta, low and high gamma oscillations (i.e., 4, 20, 40, and 80 Hz ASSR, respectively) were recorded in young, middle-aged, and older persons. As all participants had normal audiometric thresholds and were screened for (mild) cognitive impairment, differences in synchronized neural activity across the three age groups were likely to be attributed to age. Our data yield novel findings regarding theta and high gamma oscillations in the aging auditory system. At an older age, synchronized activity of theta oscillations is increased, whereas high gamma synchronization is decreased. In contrast to young persons who exhibit a right hemispheric dominance for processing of high gamma range modulations, older adults show a symmetrical processing pattern. These age-related changes in neural synchronization may very well underlie the speech perception problems in aging persons.