Ostroff Jodi M, McDonald Kelly L, Schneider Bruce A, Alain Claude
Rotman Research Institute, Baycrest Centre for Geriatric Care, 3560 Bathurst Street, M6A 2E1 ON, Toronto, Canada.
Hear Res. 2003 Jul;181(1-2):1-7. doi: 10.1016/s0378-5955(03)00113-8.
Age-related declines in coding the fine temporal structure of acoustic signals is proposed to play a critical role in the speech perception difficulties commonly observed in older individuals. This hypothesis was tested by measuring auditory evoked potentials elicited by sounds of various durations in young, middle-aged and older adults. All stimuli generated N1 and P2 waves that peaked at about 104 and 200 ms post-stimulus onset. The N1 amplitude increased linearly with increases in the tonal duration in young, middle-aged, and older adults. The P2 amplitude also increased linearly with signal duration, but only in young and middle-aged adults. The results demonstrate that the N1 and P2 waves can resolve duration differences as short as 2-4 ms and that normal aging decreases the temporal resolving power for processing small differences in sound duration.
与年龄相关的对声学信号精细时间结构编码能力的下降，被认为在老年人中常见的言语感知困难中起关键作用。通过测量年轻、中年和老年成年人对不同持续时间声音诱发的听觉诱发电位来检验这一假设。所有刺激均产生N1波和P2波，分别在刺激开始后约104毫秒和200毫秒达到峰值。年轻、中年和老年成年人的N1波幅随音调持续时间的增加呈线性增加。P2波幅也随信号持续时间呈线性增加，但仅在年轻和中年成年人中如此。结果表明，N1波和P2波能够分辨短至2-4毫秒的持续时间差异，并且正常衰老会降低处理声音持续时间微小差异的时间分辨能力。
