Increased activity in frontal motor cortex compensates impaired speech perception in older adults.
Increased activity in frontal motor cortex compensates impaired speech perception in older adults.
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DOI：
10.1038/ncomms12241
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发表时间：
2016-08-02
影响因子：
16.6
通讯作者：
Alain C
中科院分区：
文献类型：
--
作者：
Du Y;Buchsbaum BR;Grady CL;Alain C
在嘈杂的环境中理解语言是具有挑战性的，尤其是对老年人来说。尽管有证据表明老年人越来越多地使用前额叶皮层来抵消减少的外围和中央听觉处理，但这种补偿的大脑机制仍然难以捉摸。在这里，我们展示了相对于年轻人，老年人在不同信噪比的音节识别任务中表现出更高的额叶言语运动区域的激活。这种活动的增加与老年人言语辨别能力的提高有关。多体素模式分类表明，尽管整体音素去分化，老年人在额部发音区表现出比听觉区更大的音素表征特异性。此外，额叶活动较强的老年人在额叶和听觉区域具有更高的音素特异性。因此，保留的音素特异性和言语运动区域活动的上调为老年人在不利的听力条件下解码贫困的言语表征提供了一种补偿手段。老年人在嘈杂的环境中理解语言有困难，众所周知，他们的大脑通过参与前额叶区域来补偿听觉皮层中减少的感觉处理。在这里，作者发现音素特异性和言语运动区域活动的增加为老年人解码不良言语提供了一种补偿手段。
Understanding speech in noisy environments is challenging, especially for seniors. Although evidence suggests that older adults increasingly recruit prefrontal cortices to offset reduced periphery and central auditory processing, the brain mechanisms underlying such compensation remain elusive. Here we show that relative to young adults, older adults show higher activation of frontal speech motor areas as measured by functional MRI during a syllable identification task at varying signal-to-noise ratios. This increased activity correlates with improved speech discrimination performance in older adults. Multivoxel pattern classification reveals that despite an overall phoneme dedifferentiation, older adults show greater specificity of phoneme representations in frontal articulatory regions than auditory regions. Moreover, older adults with stronger frontal activity have higher phoneme specificity in frontal and auditory regions. Thus, preserved phoneme specificity and upregulation of activity in speech motor regions provide a means of compensation in older adults for decoding impoverished speech representations in adverse listening conditions. Seniors have difficulties understanding speech in noisy environments and it is known that their brains compensate reduced sensory processing in auditory cortex by engaging prefrontal areas. Here the authors find that phoneme specificity and increased activity in speech motor regions provide a means of compensation for decoding impoverished speech in older adults.