Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland; Advanced Magnetic Imaging Centre, Aalto University School of Science, Espoo, Finland.
Turku Brain and Mind Center, Department of Clinical Medicine, University of Turku, Turku, Finland.
Neuropsychologia. 2019 Feb 18;124:322-336. doi: 10.1016/j.neuropsychologia.2018.11.006. Epub 2018 Nov 13.
A number of previous studies have implicated regions in posterior auditory cortex (AC) in auditory-motor integration during speech production. Other studies, in turn, have shown that activation in AC and adjacent regions in the inferior parietal lobule (IPL) is strongly modulated during active listening and depends on task requirements. The present fMRI study investigated whether auditory-motor effects interact with those related to active listening tasks in AC and IPL. In separate task blocks, our subjects performed either auditory discrimination or 2-back memory tasks on phonemic or nonphonemic vowels. They responded to targets by either overtly repeating the last vowel of a target pair, overtly producing a given response vowel, or by pressing a response button. We hypothesized that the requirements for auditory-motor integration, and the associated activation, would be stronger during repetition than production responses and during repetition of nonphonemic than phonemic vowels. We also hypothesized that if auditory-motor effects are independent of task-dependent modulations, then the auditory-motor effects should not differ during discrimination and 2-back tasks. We found that activation in AC and IPL was significantly modulated by task (discrimination vs. 2-back), vocal-response type (repetition vs. production), and motor-response type (vocal vs. button). Motor-response and task effects interacted in IPL but not in AC. Overall, the results support the view that regions in posterior AC are important in auditory-motor integration. However, the present study shows that activation in wide AC and IPL regions is modulated by the motor requirements of active listening tasks in a more general manner. Further, the results suggest that activation modulations in AC associated with attention-engaging listening tasks and those associated with auditory-motor performance are mediated by independent mechanisms.
先前的一些研究表明，在言语产生过程中，后听觉皮层（AC）的区域与听觉-运动整合有关。其他研究则表明，在积极聆听过程中，AC 和下顶叶（IPL）的相邻区域的激活受到强烈的调节，并且取决于任务的要求。本 fMRI 研究探讨了听觉-运动效应是否与 AC 和 IPL 中与积极聆听任务相关的效应相互作用。在单独的任务块中，我们的被试分别对语音或非语音元音进行听觉辨别或 2 回记忆任务。他们通过以下方式对目标做出反应：通过明显地重复目标对的最后一个元音、明显地产生给定的响应元音，或者通过按下响应按钮。我们假设，在重复比产生反应时，以及在重复非语音元音比语音元音时，听觉-运动整合的要求和相关的激活会更强。我们还假设，如果听觉-运动效应独立于任务相关的调节，那么在辨别和 2 回任务期间，听觉-运动效应不应不同。我们发现，AC 和 IPL 的激活受到任务（辨别与 2 回）、发声反应类型（重复与产生）和运动反应类型（发声与按钮）的显著调节。运动反应和任务效应在 IPL 中相互作用，但在 AC 中没有。总的来说，这些结果支持了这样一种观点，即后 AC 中的区域在听觉-运动整合中很重要。然而，本研究表明，广泛的 AC 和 IPL 区域的激活受到积极聆听任务的运动要求的更一般的调节。此外，结果表明，与注意力吸引的聆听任务相关的 AC 激活调节以及与听觉-运动表现相关的激活调节是由独立的机制介导的。
