Department of Pharmacology, Nippon Medical School, 1-1-5, Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan.
Neurosci Res. 2010 May;67(1):65-71. doi: 10.1016/j.neures.2010.02.006. Epub 2010 Feb 17.
Comprehending conversation in a crowd requires appropriate orienting and sustainment of auditory attention to and discrimination of the target speaker. While a multitude of cognitive functions such as voice perception and language processing work in concert to subserve this ability, it is still unclear which cognitive components critically determine successful discrimination of speech sounds under constantly changing auditory conditions. To investigate this, we present a functional magnetic resonance imaging (fMRI) study of changes in cerebral activities associated with varying challenge levels of speech discrimination. Subjects participated in a diotic listening paradigm that presented them with two news stories read simultaneously but independently by a target speaker and a distracting speaker of incongruent or congruent sex. We found that the voice of distracter of congruent rather than incongruent sex made the listening more challenging, resulting in enhanced activities mainly in the left temporal and frontal gyri. Further, the activities at the left inferior, left anterior superior and right superior loci in the temporal gyrus were shown to be significantly correlated with accuracy of the discrimination performance. The present results suggest that the subregions of bilateral temporal gyri play a key role in the successful discrimination of speech under constantly changing auditory conditions as encountered in daily life.
理解人群中的对话需要适当的定向和持续的听觉注意力，并对目标说话者进行辨别。虽然许多认知功能（如语音感知和语言处理）协同工作以支持这种能力，但仍不清楚哪些认知成分对于在不断变化的听觉条件下成功辨别语音至关重要。为了研究这一点，我们进行了一项功能性磁共振成像（fMRI）研究，以研究与语音辨别不同难度水平相关的大脑活动变化。受试者参与了双声道听力范式，该范式向他们呈现了两个同时由目标说话者和分心说话者以不相关或相关性别独立阅读的新闻故事。我们发现，与不相关性别相比，分心说话者的声音会使听力更具挑战性，从而导致主要在左侧颞叶和额叶回增强的活动。此外，颞叶回的左侧下、左侧上前和右侧上三个位置的活动与辨别性能的准确性显著相关。这些结果表明，双侧颞叶回的亚区在日常生活中遇到的不断变化的听觉条件下成功辨别语音方面起着关键作用。
