Department of Psychology & Brain and Mind Institute, The University of Western Ontario, London, ON, Canada; Rotman Research Institute, Baycrest, North York, ON, Canada; Department of Psychology, University of Toronto, Toronto, ON, Canada.
Brain Networks Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
Neurobiol Aging. 2022 Jan;109:1-10. doi: 10.1016/j.neurobiolaging.2021.09.011. Epub 2021 Sep 17.
Sensitivity to repetitions in sound amplitude and frequency is crucial for sound perception. As with other aspects of sound processing, sensitivity to such patterns may change with age, and may help explain some age-related changes in hearing such as segregating speech from background sound. We recorded magnetoencephalography to characterize differences in the processing of sound patterns between younger and older adults. We presented tone sequences that either contained a pattern (made of a repeated set of tones) or did not contain a pattern. We show that auditory cortex in older, compared to younger, adults is hyperresponsive to sound onsets, but that sustained neural activity in auditory cortex, indexing the processing of a sound pattern, is reduced. Hence, the sensitivity of neural populations in auditory cortex fundamentally differs between younger and older individuals, overresponding to sound onsets, while underresponding to patterns in sounds. This may help to explain some age-related changes in hearing such as increased sensitivity to distracting sounds and difficulties tracking speech in the presence of other sound.
对声音幅度和频率重复的敏感性对于声音感知至关重要。与声音处理的其他方面一样，对这种模式的敏感性可能会随年龄而变化，并且可能有助于解释听力的一些与年龄相关的变化，例如将语音与背景声音区分开来。我们记录了脑磁图，以描述年轻人和老年人在声音模式处理方面的差异。我们呈现了包含模式（由重复的一组音调组成）或不包含模式的音调序列。我们表明，与年轻人相比，老年人的听觉皮层对声音起始更为敏感，但听觉皮层中持续的神经活动（表示声音模式的处理）减少了。因此，听觉皮层中神经群体的敏感性在年轻人和老年人之间存在根本差异，对声音起始反应过度，而对声音中的模式反应不足。这有助于解释听力的一些与年龄相关的变化，例如对分散注意力的声音的敏感性增加以及在存在其他声音的情况下跟踪语音的困难。
