Geal-Dor Miriam, Goldstein Abraham, Kamenir Yury, Babkoff Harvey
Faculty of Life Science, Bar Ilan University, Ramat Gan, Israel.
Clin Neurophysiol. 2006 Sep;117(9):1974-89. doi: 10.1016/j.clinph.2006.05.024. Epub 2006 Jul 20.
To investigate age-related changes in speech perception by measuring event-related potentials (ERPs) elicited by auditory stimuli varying in their linguistic characteristics from pure tones to words.
ERPs were recorded from 64 subjects in three age groups (young, middle age and elderly) to auditory target stimuli, using an oddball paradigm. Three different tasks and stimuli were used: tonal, phonological and semantic.
N100 latency to tonal targets was significantly shorter than to both types of speech targets. P300 latency to tonal targets was significantly shorter than to phonological targets, which in turn was shorter than to semantic targets. P300 amplitude recorded to the speech targets was significantly larger over the left hemisphere than over the right hemisphere in the young subjects. However, the reverse pattern of asymmetry, favoring the right hemisphere was found in the elderly subjects. The pattern of the hemispheric distribution for the middle aged was somewhere in between the young and elderly.
The data indicate possible progressive changes in left-right asymmetry in language processing with aging.
Findings may indicate an increased use of compensatory mechanisms for speech processing, or alternatively, an increased use of different generators as individuals age.
通过测量由从纯音到单词等语言特征各异的听觉刺激所诱发的事件相关电位（ERP），来研究语音感知中与年龄相关的变化。
采用奇偶数范式，记录了三个年龄组（青年、中年和老年）的64名受试者对听觉目标刺激的ERP。使用了三种不同的任务和刺激：音调、音系和语义。
对音调目标的N100潜伏期显著短于对两种语音目标的潜伏期。对音调目标的P300潜伏期显著短于对音系目标的潜伏期，而对音系目标的潜伏期又短于对语义目标的潜伏期。在青年受试者中，记录到的语音目标的P300波幅在左半球显著大于右半球。然而，在老年受试者中发现了相反的不对称模式，即右半球更占优势。中年人的半球分布模式介于青年和老年之间。
数据表明，随着年龄增长，语言处理中左右不对称可能会逐渐发生变化。
研究结果可能表明，随着个体年龄增长，语音处理中补偿机制的使用增加，或者不同发生器的使用增加。
