Ishida Osamu, Iimura Daichi, Miyamoto Shoko
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan.
Saitama Municipal Nakamoto Elementary School, Saitama, Japan.
Front Hum Neurosci. 2020 Feb 26;14:51. doi: 10.3389/fnhum.2020.00051. eCollection 2020.
Delayed auditory feedback (DAF) leads to nonfluent speech where the voice of a speaker is heard after a delay. Previous studies suggested the involvement of attention to auditory feedback in speech disfluency. To date, there are no studies that have revealed the relationship between attention and nonfluent speech by controlling the attention allocated to the delayed own voice. This study examined these issues under three conditions: a single task where the subject was asked to read aloud under DAF (single DAF task), a dual task where the subject was asked to read aloud while reacting to a pure tone (auditory DAF task), and a dual task where the subject was asked to read aloud while reacting to the vibration of their finger (tactile DAF task). The subjects also performed the single and dual tasks (auditory/tactile) under nonaltered auditory feedback where no delayed voices were involved. Results showed that the nonfluency rate under the auditory DAF task was significantly greater than that under the single DAF task. In contrast, the nonfluency rate under the tactile DAF task was significantly lower compared with that of the single DAF task. Speech became nonfluent when attention was captured by the same modality stimulus, i.e., auditory tone. In contrast, speech became fluent when attention was allocated to the stimulus that is irreverent to auditory modality, i.e., tactile vibration. This indicates that nonfluent speech under DAF is involved in attention capture owing to the delayed own voice.
延迟听觉反馈（DAF）会导致言语不流畅，即说话者的声音在延迟后被听到。先前的研究表明，对听觉反馈的注意力参与了言语不流畅。迄今为止，尚无研究通过控制分配给延迟的自身声音的注意力来揭示注意力与言语不流畅之间的关系。本研究在三种条件下考察了这些问题：一种单一任务，要求受试者在DAF下大声朗读（单一DAF任务）；一种双重任务，要求受试者在对纯音做出反应的同时大声朗读（听觉DAF任务）；以及一种双重任务，要求受试者在对手指振动做出反应的同时大声朗读（触觉DAF任务）。受试者还在未改变的听觉反馈（不涉及延迟声音）下执行单一和双重任务（听觉/触觉）。结果表明，听觉DAF任务下的不流畅率显著高于单一DAF任务下的不流畅率。相比之下，触觉DAF任务下的不流畅率与单一DAF任务相比显著更低。当注意力被相同模态的刺激（即听觉音调）捕获时，言语变得不流畅。相反，当注意力分配到与听觉模态无关的刺激（即触觉振动）时，言语变得流畅。这表明DAF下的言语不流畅与由于延迟的自身声音导致的注意力捕获有关。
