Laboratoire de Sciences Phonétiques, Département de Linguistique et de Traduction, Université de Montréal, Montréal, QC, Canada.
Laboratoire de Recherche en Neurosciences et Électrophysiologie Cognitive, Hôpital Rivière-des-Prairies, Montréal, QC, Canada.
PLoS One. 2021 Apr 16;16(4):e0250214. doi: 10.1371/journal.pone.0250214. eCollection 2021.
Research has repeatedly shown that familiar and unfamiliar voices elicit different neural responses. But it has also been suggested that different neural correlates associate with the feeling of having heard a voice and knowing who the voice represents. The terminology used to designate these varying responses remains vague, creating a degree of confusion in the literature. Additionally, terms serving to designate tasks of voice discrimination, voice recognition, and speaker identification are often inconsistent creating further ambiguities. The present study used event-related potentials (ERPs) to clarify the difference between responses to 1) unknown voices, 2) trained-to-familiar voices as speech stimuli are repeatedly presented, and 3) intimately familiar voices. In an experiment, 13 participants listened to repeated utterances recorded from 12 speakers. Only one of the 12 voices was intimately familiar to a participant, whereas the remaining 11 voices were unfamiliar. The frequency of presentation of these 11 unfamiliar voices varied with only one being frequently presented (the trained-to-familiar voice). ERP analyses revealed different responses for intimately familiar and unfamiliar voices in two distinct time windows (P2 between 200-250 ms and a late positive component, LPC, between 450-850 ms post-onset) with late responses occurring only for intimately familiar voices. The LPC present sustained shifts, and short-time ERP components appear to reflect an early recognition stage. The trained voice equally elicited distinct responses, compared to rarely heard voices, but these occurred in a third time window (N250 between 300-350 ms post-onset). Overall, the timing of responses suggests that the processing of intimately familiar voices operates in two distinct steps of voice recognition, marked by a P2 on right centro-frontal sites, and speaker identification marked by an LPC component. The recognition of frequently heard voices entails an independent recognition process marked by a differential N250. Based on the present results and previous observations, it is proposed that there is a need to distinguish between processes of voice "recognition" and "identification". The present study also specifies test conditions serving to reveal this distinction in neural responses, one of which bears on the length of speech stimuli given the late responses associated with voice identification.
研究反复表明，熟悉和不熟悉的声音会引起不同的神经反应。但也有人认为，不同的神经关联与听到声音的感觉以及知道声音代表谁有关。用于指定这些不同反应的术语仍然模糊不清，这在文献中造成了一定程度的混淆。此外，用于指定语音辨别、语音识别和说话人识别任务的术语往往不一致，从而造成了更多的歧义。本研究使用事件相关电位（ERP）来澄清对以下三种情况的反应差异：1）未知声音，2）经过训练的熟悉声音，因为语音刺激会反复呈现，以及 3）非常熟悉的声音。在一项实验中，13 名参与者听取了来自 12 名说话者的重复话语。只有 12 个声音中的一个与参与者非常熟悉，而其余 11 个声音则不熟悉。这些不熟悉的声音的呈现频率各不相同，其中只有一个声音经常呈现（即经过训练的熟悉声音）。ERP 分析显示，在两个不同的时间窗口内，非常熟悉的声音和不熟悉的声音有不同的反应（P2 在 200-250ms 之间，而晚期正成分 LPC 在起始后 450-850ms 之间），只有非常熟悉的声音才有晚期反应。LPC 呈现持续的变化，而短时间的 ERP 成分似乎反映了早期的识别阶段。与很少听到的声音相比，经过训练的声音同样引起了明显的反应，但这些反应发生在第三个时间窗口（N250 在起始后 300-350ms 之间）。总体而言，反应的时间表明，非常熟悉的声音的处理需要经过两个不同的语音识别步骤，在右中央额区有一个 P2，在说话人识别时有一个 LPC 成分。经常听到的声音的识别需要一个独立的识别过程，这一过程由一个有差别的 N250 来标记。基于目前的结果和以前的观察，有必要区分语音“识别”和“识别”的过程。本研究还提出了需要区分语音“识别”和“识别”的过程。本研究还提出了需要区分语音“识别”和“识别”的过程。本研究还指定了用于揭示神经反应中这种区别的测试条件，其中一个条件与与语音识别相关的晚期反应有关，即语音刺激的长度。
