Human auditory cortical processing of changes in interaural correlation
Human auditory cortical processing of changes in interaural correlation
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DOI：
10.1523/jneurosci.1266-05.2005
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发表时间：
2005-09-14
影响因子：
5.3
通讯作者：
Simon, JZ
中科院分区：
文献类型：
--
作者：
Chait, M;Poeppel, D;Simon, JZ
对两耳声波波形相似性的敏感性，特别是对相似性变化的敏感性，对于听觉场景分析和从背景中提取对象至关重要。在这里，我们使用脑磁图的高时间分辨率来研究耳间相关性（耳间相似性的度量）变化的皮质处理动态，并将其与行为进行比较。刺激是耳间相关或不相关的宽带噪声，紧接着是具有中等程度耳间相关性的相同噪声。从行为上来说，听众对耳间相关性变化的敏感度是不对称的。与不相关噪声的转换相比，听众能够更快更好地检测相关噪声的转换。皮质对相关性变化的反应的特征是从变化后大约 50 毫秒开始的激活序列。这种反应的强度与行为表现平行：听觉皮层机制对不相关噪声的转变的敏感度远低于相关噪声的敏感度。在每种情况下，灵敏度随着耳间相关性差异的增加而增加。大脑对不相关噪声转变的反应滞后于相关噪声约 80 毫秒，这可能是观察到的行为反应时间差异的神经相关性。重要的是，我们证明了神经处理的位置和时间过程的差异：相关噪声的转换由不同的神经群体处理，并且比不相关噪声的转换速度更快。
Sensitivity to the similarity of the acoustic waveforms at the two ears, and specifically to changes in similarity, is crucial to auditory scene analysis and extraction of objects from background. Here, we use the high temporal resolution of magnetoencephalography to investigate the dynamics of cortical processing of changes in interaural correlation, a measure of interaural similarity, and compare them with behavior. Stimuli are interaurally correlated or uncorrelated wideband noise, immediately followed by the same noise with intermediate degrees of interaural correlation. Behaviorally, listeners' sensitivity to changes in interaural correlation is asymmetrical. Listeners are faster and better at detecting transitions from correlated noise than transitions from uncorrelated noise. The cortical response to the change in correlation is characterized by an activation sequence starting from similar to 50 ms after change. The strength of this response parallels behavioral performance: auditory cortical mechanisms are much less sensitive to transitions from uncorrelated noise than from correlated noise. In each case, sensitivity increases with interaural correlation difference. Brain responses to transitions from uncorrelated noise lag those from correlated noise by similar to 80 ms, which may be the neural correlate of the observed behavioral response time differences. Importantly, we demonstrate differences in location and time course of neural processing: transitions from correlated noise are processed by a distinct neural population, and with greater speed, than transitions from uncorrelated noise.