ABSTRACT

Speech perception involves segmenting a continuous stream of speech into its word components. This can be challenging in the case of homophonous utterances only differing in non-contrastive subphonemic features. Yet, the speech perception system seems able to discriminate subphonemic deviation in homophonous utterances, since it has been shown to elicit a mismatch response (MMN). Here, we focused on the oscillatory correlates, namely phase resetting and power, of non-contrastive subphonemic deviation processing in language. An oddball task that considered natural intraspeaker variability was used.

Subphonemic deviance elicited intertrial phase coherence (ITC) differences in the theta band at Fz during the time window of the MMN. No differences in power were found. This suggests that the processing of subphonemic deviation in speech signals, reflected by the MMN, might rely on mechanisms of phase resetting. ITC might facilitate the synchronous firing of functional networks involved in the processing of subphonemic deviance.

摘要

语音感知涉及将连续的语音流分割成其单词成分。对于仅在非对比次音位特征上有所不同的同音话语，这可能具有挑战性。然而，语音感知系统似乎能够区分同音话语中的亚音位偏差，因为它已被证明会引发不匹配响应 (MMN)。在这里，我们专注于语言中非对比次音位偏差处理的振荡相关性，即相位重置和功率。使用了考虑自然说话者内部可变性的古怪任务。

在 MMN 的时间窗口期间，亚音位偏差在 Fz 处的 theta 频带中引起了中间相位相干性 (ITC) 差异。没有发现功率差异。这表明，由 MMN 反映的语音信号中亚音位偏差的处理可能依赖于相位重置机制。ITC 可能会促进参与处理亚音位偏差的功能网络的同步触发。