基于功能性近红外光谱成像技术研究增龄对听觉皮层言语感知功能的影响

The function of auditory cortex in the elderly using functional near-infrared spectroscopy technology

目的:利用功能性近红外光谱成像技术(functional near-infrared spectroscopy,fNIRS)研究年龄老化对言语感知过程中大脑皮层神经成像特征的影响。方法:2021年3—6月招募听力正常成人34名,其中青年组17名[男6名,女11名,年龄(32.1±5.0)岁(20~39岁)],老年组17名[男6名,女11名,年龄(63.2±2.8)岁(60~70岁)]。测试材料为汉语普通话噪声下言语测试句表,采用任务态block实验设计,以左右颞叶、Broca区、Wernicke区、运动皮层为感兴趣区,运用客观脑成像fNIRS技术并结合主观心理物理学测试方法,分析老年人及青年人在不同聆听条件(安静、信噪比为10 dB、5 dB、0 dB、-5 dB)下,与听觉言语感知功能相关的大脑皮层激活区域及激活程度。采用SPSS 23软件进行统计学分析。结果:老年组在各个任务条件下的激活区域及激活程度均较青年组减小;青年组整体激活通道数明显多于老年组,且左半球激活通道多于右半球,而老年组左右半球激活通道数差异不大;大脑左半球受年龄因素影响显著的通道较右半球多。青年组在信噪比为0 dB时的激活程度显著高于其他信噪比条件( P<0.05),而老年组在5种条件下的激活程度差异无统计学意义( P值均>0.05);青年组各条件下的言语识别得分均高于老年组,两组得分在信噪比为5 dB时差异开始有统计学意义( P<0.05);青年组在信噪比为0 dB时的言语识别正确率下降明显,而老年组在信噪比为5 dB时开始出现明显下降。 结论:年龄老化导致嘈杂环境下言语感知能力以及大脑皮层的活跃程度逐渐发生退化,言语优势半球(左半球)受年龄老化影响显著,老年人在不同言语清晰度任务下的整体激活区域及激活程度均较青年人减小。

Objective Functional near-infrared spectroscopy(fNIRS)was used to study the effect of aging on the neuroimaging characteristics of cerebral cortex in the process of speech perception.Method Thirty-four adults with normal hearing were recruited from March 2021 to June 2021,including 17 in the young group,with 6 males,11 females,age(32.1±5.0)years,age range 20-39 years.and 17 in the elderly group,with 6 males,11 females,age(63.2±2.8)years,age range 60-70 years.The test material was the sentence table of the Mandarin Hearing Test in Noise(MHINT).The task state block experiment design was adopted,and the temporal lobe,Broca's area,Wernicke's area,motor cortex were used as regions of interest.Objective brain imaging technology(fNIRS)combined with subjective psychophysical testing method was used to analyze the activation area and degree of cerebral cortex related to auditory speech perception in the elderly and young people under different listening conditions(quiet,signal-to-noise ratio of 10 dB,5 dB,0 dB,-5 dB).SPSS 23 software was used for statistical analysis.Result The activation area and degree of activation in the elderly group were lower than those in the young group under each task condition;The number of activation channels in the young group were significantly more than those in the old group,and the number of activation channels in the left hemisphere were more than those in the right hemisphere,but there was no difference in the number of activation channels.There were more channels affected by age in the left hemisphere than in the right hemisphere.The activation degree of the young group when the signal-to-noise ratio was 0 dB was significantly higher than that of other signal-to-noise ratio conditions(P<0.05),but there was no significant difference in the old group under the five conditions(P>0.05).The speech recognition score of the young group was higher than that of the old group under all conditions.When the quiet and signal-to-noise ratio was 10 dB,the correct score of the two groups was equal or close to 100%.With the gradual decrease of signal-to-noise ratio,there was a significant difference between the two groups when the signal-to-noise ratio was 5 dB.The speech recognition accuracy of the young group decreased significantly when the signal-to-noise ratio was 0 dB,while that of the old group decreased significantly when the signal-to-noise ratio was 5 dB.Conclusions With the increase of age,the speech perception in noisy environment and the activity of cerebral cortex gradually deteriorate,and the speech dominance hemisphere(left hemisphere)will be significantly affected by aging.The overall activation area and activation degree of the elderly under different speech tasks are lower than those of the young.