Department of Psychology, Tufts University, Medford, MA, USA.
Department of Computer Science, Tufts University, Medford, MA, USA.
Sci Rep. 2023 Mar 1;13(1):3458. doi: 10.1038/s41598-023-30435-z.
A key mechanism in the comprehension of conversation is the ability for listeners to recognize who is speaking and when a speaker switch occurs. Some authors suggest that speaker change detection is accomplished through bottom-up mechanisms in which listeners draw on changes in the acoustic features of the auditory signal. Other accounts propose that speaker change detection involves drawing on top-down linguistic representations to identify who is speaking. The present study investigates these hypotheses experimentally by manipulating the pragmatic coherence of conversational utterances. In experiment 1, participants listened to pairs of utterances and had to indicate whether they heard the same or different speakers. Even though all utterances were spoken by the same speaker, our results show that when two segments of conversation are spoken by the same speaker but make sense for different speakers to say, listeners report hearing different speakers. In experiment 2 we removed pragmatic information from the same stimuli by scrambling word order while leaving acoustic information intact. In contrast to experiment 1, results from the second experiment indicate no difference between our experimental conditions. We interpret these results as a top-down effect of pragmatic expectations: knowledge of conversational structure at least partially determines a listener's perception of speaker changes in conversation.
在对话理解中，一个关键机制是听者识别说话人身份以及说话人何时发生转换的能力。一些作者认为，说话人转换检测是通过听者利用听觉信号的声学特征变化的自下而上的机制来完成的。其他的解释则提出，说话人转换检测涉及到利用自上而下的语言表示来识别说话人。本研究通过操纵会话话语的语用连贯来实验性地研究这些假设。在实验 1 中，参与者听了成对的话语，然后必须指出他们听到的是同一个还是不同的说话人。尽管所有的话语都是同一个说话人说的，但我们的结果表明，当两段对话由同一个说话人说，但听起来像是不同的说话人说的，听者会报告听到不同的说话人。在实验 2 中，我们通过打乱语序来从相同的刺激中去除语用信息，而保持声学信息不变。与实验 1 相反，第二个实验的结果表明，我们的实验条件之间没有差异。我们将这些结果解释为语用期望的自上而下效应：对话结构的知识至少部分决定了听者在对话中对说话人变化的感知。
