Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom; School of Sports Sciences and Human Movement, CIAMS, Université Paris-Sud, Université Paris-Saclay, Orsay, France; UFR Collegium Sciences et Techniques, CIAMS, Université d'Orléans, Orléans, France.
Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom; School of Psychology, University of Nottingham, Nottingham, UK.
Neurobiol Aging. 2018 Dec;72:89-97. doi: 10.1016/j.neurobiolaging.2018.07.013. Epub 2018 Jul 29.
Older adults often experience difficulties in understanding speech, partly because of age-related hearing loss (HL). In young adults, activity of the left articulatory motor cortex is enhanced and it interacts with the auditory cortex via the left-hemispheric dorsal stream during speech processing. Little is known about the effect of aging and age-related HL on this auditory-motor interaction and speech processing in the articulatory motor cortex. It has been proposed that upregulation of the motor system during speech processing could compensate for HL and auditory processing deficits in older adults. Alternatively, age-related auditory deficits could reduce and distort the input from the auditory cortex to the articulatory motor cortex, suppressing recruitment of the motor system during listening to speech. The aim of the present study was to investigate the effects of aging and age-related HL on the excitability of the tongue motor cortex during listening to spoken sentences using transcranial magnetic stimulation and electromyography. Our results show that the excitability of the tongue motor cortex was facilitated during listening to speech in young and older adults with normal hearing. This facilitation was significantly reduced in older adults with HL. These findings suggest a decline of auditory-motor processing of speech in adults with age-related HL.
老年人在理解言语时常常会遇到困难，部分原因是与年龄相关的听力损失（HL）。在年轻人中，在言语处理过程中，左发音运动皮层的活动增强，并通过左半球的背侧流与听觉皮层相互作用。对于衰老和与年龄相关的 HL 对发音运动皮层中的这种听觉-运动相互作用和言语处理的影响知之甚少。有人提出，在言语处理过程中运动系统的上调可以补偿老年人的 HL 和听觉处理缺陷。或者，与年龄相关的听觉缺陷可能会减少并扭曲来自听觉皮层到发音运动皮层的输入，从而抑制在听言语时运动系统的募集。本研究旨在使用经颅磁刺激和肌电图研究衰老和与年龄相关的 HL 对听句子时舌运动皮层兴奋性的影响。我们的结果表明，在听力正常的年轻人和老年人中，听言语时舌运动皮层的兴奋性增强。在有 HL 的老年人中，这种增强显著降低。这些发现表明，与年龄相关的 HL 的成年人的言语听觉-运动处理能力下降。
