Role of pattern, regularity, and silent intervals in auditory stream segregation based on inter-aural time differences
Role of pattern, regularity, and silent intervals in auditory stream segregation based on inter-aural time differences
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DOI：
10.1007/s00221-012-3333-z
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发表时间：
2013-02-01
影响因子：
2
通讯作者：
Gutschalk, Alexander
中科院分区：
文献类型：
--
作者：
Carl, David;Gutschalk, Alexander
由停顿隔开的声调三元组(ABA_)是一种常用的声调重复模式，用于研究听流分离。这样的三胞胎在融合时会产生奔腾的节奏，但在分离时会产生同步的节奏。其他缺乏停顿的模式可能会产生不太明显的节奏差异，但会产生更强的串流。在这里，我们评估了这种差异是否容易用停顿的存在来解释，并潜在地与顺应性的减少有关，或者是否存在语调模式本身的贡献。脑磁图显示重复的ABA型和ABA型序列。通过耳间时差差值(Delta ITD)将A和B音区分开。结果表明，ABAA的流出越强，听觉皮层P(1)m的适应释放越明显。我们进一步比较了有和没有停顿的模式的行为流传输反应，并改变了停顿的位置和模式的规律性。结果显示，停顿的存在是主要影响因素，而声调模式或模式规律性的影响不显著。这些结果证明存在一种早期的、原始的流媒体机制，该机制不需要对听觉流媒体的预测编码模型所建议的后期阶段的音调模式进行分析。更简单的群体分离模型更好地解释了这一结果，并强调了先前观察到的神经适应对心流知觉的作用。
Tone triplets separated by a pause (ABA_) are a popular tone-repetition pattern to study auditory stream segregation. Such triplets produce a galloping rhythm when integrated, but isochronous rhythms when segregated. Other patterns lacking a pause may produce less-prominent rhythmic differences but stronger streaming. Here, we evaluated whether this difference is readily explained by the presence of the pause and potentially associated with the reduction of adaptation, or whether there is contribution of tone pattern per se. Sequences with repetitive ABA_ and ABAA patterns were presented in magnetoencephalography. A and B tones were separated by differences in inter-aural time differences (Delta ITD). Results showed that the stronger streaming of ABAA was associated with a more prominent release from the adaptation of the P(1)m in auditory cortex. We further compared behavioral streaming responses for patterns with and without pauses, and varied the position of the pause and pattern regularity. Results showed a major effect of the pauses' presence, but no prominent effects of tone pattern or pattern regularity. These results make a case for the existence of an early, primitive streaming mechanism that does not require an analysis of the tone pattern at later stages suggested by predictive-coding models of auditory streaming. The results are better explained by the simpler population-separation model and stress the previously observed role of neural adaptation for streaming perception.