University of Zurich, Division of Neuropsychology,Psychological Institute, Binzmühlestrasse 14, 8050, Zurich, Switzerland; University Research Priority Program "Dynamics of Healthy Aging", University of Zurich, Switzerland.
University of Zurich, Division of Neuropsychology,Psychological Institute, Binzmühlestrasse 14, 8050, Zurich, Switzerland; University Research Priority Program "Dynamics of Healthy Aging", University of Zurich, Switzerland.
Neuroimage. 2019 Apr 1;189:886-895. doi: 10.1016/j.neuroimage.2019.01.050. Epub 2019 Jan 24.
This study combines event-related sparse-temporal acquisition fMRI with structural MRI to investigate older participants (n = 26, mean age = 70.64) with age-typical peripheral hearing. While participants were presented with locally time-reversed sentences of varying temporal integrity, they performed an auditory pattern-matching task. The major aim of the study was to find out whether functional lateralization for speech perception according to the 'Asymmetric Sampling in Time' (AST) hypothesis shows a similar pattern in elderly individuals as has been previously observed in younger adults. Our findings indicate that, unlike results previously obtained from younger adults, older individuals did not demonstrate the same pattern of rightward lateralization in response to suprasegmental speech cues in the three auditory regions of interest (ROI), namely Heschl's gyrus (HG), planum temporale (PT) and posterior lateral superior temporal gyrus (pSTG). A frequentist statistical approach did not yield evidence for functional lateralization in the aging brain, and this was corroborated by Bayesian evidence which supported the absence of lateralization in older adults in response to the suprasegmental manipulation. However, a relationship between structural measurements and functional responses demonstrated that individuals with thicker right PT showed less variance in lateralization. Hence, this study extends the division of labour between the left and the right auditory cortex during the processing of continuous spoken language as proposed by the 'AST'-hypothesis in younger adults to a lifespan context.
本研究结合事件相关稀疏时间获取 fMRI 与结构 MRI，来调查具有典型年龄相关性外周听力的老年参与者（n=26，平均年龄=70.64）。当参与者接受不同时间完整性的局部时间反转句子时，他们执行了听觉模式匹配任务。该研究的主要目的是确定根据“时间非对称采样”（AST）假设的言语感知功能侧化是否与以前在年轻成年人中观察到的模式相似。我们的研究结果表明，与年轻成年人的先前结果不同，老年人在三个听觉感兴趣区域（HG、PT 和后外侧上颞回（pSTG））中，对于超音段言语线索没有表现出与右侧化相同的模式。频率统计方法没有为衰老大脑中的功能侧化提供证据，贝叶斯证据也支持了老年人对超音段操作没有侧化的支持。然而，结构测量值与功能反应之间的关系表明，右侧 PT 较厚的个体在侧化方面的变化较小。因此，本研究将“AST”假说在年轻成年人中提出的连续语言处理过程中左、右听觉皮层之间的分工扩展到整个生命周期的背景。
