Recovery and refractoriness of auditory evoked fields after gaps in click trains
Recovery and refractoriness of auditory evoked fields after gaps in click trains
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DOI：
10.1111/j.1460-9568.2004.03767.x
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发表时间：
2004-12-01
影响因子：
3.4
通讯作者：
Rupp, A
中科院分区：
文献类型：
--
作者：
Gutschalk, A;Patterson, RD;Rupp, A
当在列车上以类似于5赫兹以上的频率呈现咔哒声时，它们会在人类听觉皮质中唤起一个可由脑磁图记录的持续磁场。在这项研究中，我们评估了当点击序列被无声间隙打断时，这种持续的场是如何继续的。刺激是点击间隔为12或24毫秒的点击序列，分别产生83.3或41.7赫兹的音调。短声串持续时间为996毫秒，间隔为12、24、48、96或192毫秒，开始于刺激后504毫秒。具有短间隙的短声串的持续场与连续声串所诱发的场相似。减去由504毫秒的单独点击序列所引起的响应，使得能够估计在间隔之后的持续场。比较发现，在短声后150~350ms这段时间内，短声后的持续场幅大于短声起始时的持续场幅，且差异随空隙持续时间的延长而减小。相反，瞬时P1m对于长达48ms的间隔是不稳定的，但对于192ms的间隔几乎恢复了它的初始幅度。我们讨论这些结果可能如何与感知相关，即，如果中断的咔哒声序列被感知为具有瞬时间隙的一个连续声音，或者被感知为两个连续事件。
When clicks are presented in a train at a rate above similar to5 Hz, they evoke a sustained field in human auditory cortex that can be recorded by magnetoencephalography. In this study we evaluated how this sustained field continues when a click train is interrupted by a silent gap. The stimuli were click trains with interclick intervals of either 12 or 24 ms, which produce pitches of 83.3 or 41.7 Hz, respectively. The click trains were 996 ms in duration with a gap of 12, 24, 48, 96, or 192 ms beginning 504 ms post-stimulus onset. The sustained field for click trains with short gaps was similar to the one evoked by a continuous click train. Subtraction of the response evoked by a solitary click train of 504 ms enabled estimation of the sustained field in the interval after the gap. The comparison revealed that the sustained field amplitude after the gap was larger than that at the onset of the initial click train in the interval from 150 to 350 ms after onset, and the difference decreased with gap duration. In contrast, the transient P1m was refractory for gaps up to 48 ms, but had nearly recovered its initial amplitude for gaps of 192 ms. We discuss how these results might relate to the perception, i.e. if an interrupted click train is perceived as one continuous sound with a transient gap or as two successive events.