Curriculum Studies Department, College of Education, University of Hawai`i at Mānoa, Honolulu, HI, USA.
Centre for Computer Research in Music and Acoustics, Department of Music, Stanford University, Stanford, CA, USA; Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
Neuropsychologia. 2019 Jun;129:223-235. doi: 10.1016/j.neuropsychologia.2019.03.022. Epub 2019 Apr 3.
Music and language processing share and sometimes compete for brain resources. An extreme case of such shared processing occurs in improvised rap music, in which performers, or 'lyricists', combine rhyming, rhythmic, and semantic structures of language with musical rhythm, harmony, and phrasing to create integrally meaningful musical expressions. We used event-related potentials (ERPs) to investigate how auditory rhyme sequence processing differed between expert lyricists and non-lyricists. Participants listened to rhythmically presented pseudo-word triplets each of which terminated in a full-rhyme (e.g., STEEK, PREEK; FLEEK), half-rhyme (e.g., STEEK, PREEK; FREET), or non-rhyme (e.g., STEEK, PREEK; YAME), then judged each sequence in its aesthetic (Do you 'like' the rhyme?) or technical (Is the rhyme 'perfect'?) aspect. Phonological N450 showed rhyming effects between conditions (i.e., non vs. full; half vs. full; non vs. half) similarly across groups in parietal electrodes. However, concurrent activity in frontocentral electrodes showed left-laterality in non-lyricists, but not lyricists. Furthermore, non-lyricists' responses to the three conditions were distinct in morphology and amplitude at left-hemisphere electrodes with no condition difference at right-hemisphere electrodes, while lyricists' responses to half-rhymes they deemed unsatisfactory were similar to full-rhyme at left-hemisphere electrodes, and similar to non-rhyme at right-hemisphere electrodes. The CNV response observed while waiting for the second and third pseudo-word in the sequence was more enhanced to aesthetic rhyme judgments tasks than to technical rhyme judgment tasks in non-lyricists, suggesting their investment of greater effort for aesthetic rhyme judgments. No task effects were observed in lyricists, suggesting that aesthetic and technical rhyme judgments may engage the same processes for experts. Overall, our findings suggest that extensive practice of improvised lyricism may uniquely encourage the neuroplasticity of integrated linguistic and musical feature processing in the brain.
音乐和语言处理共享资源，有时也相互竞争。在即兴说唱音乐中，表演者（即“说唱歌手”）将语言的押韵、节奏和语义结构与音乐的节奏、和声和乐句结合起来，创造出具有整体意义的音乐表达，这是一种极端的共享处理情况。我们使用事件相关电位（ERP）来研究听觉押韵序列处理在专家说唱歌手和非说唱歌手之间的差异。参与者听节奏呈现的伪词三胞胎，每个三胞胎都以全押韵（例如，STEEK、PREEK；FLEEK）、半押韵（例如，STEEK、PREEK；FREET）或非押韵（例如，STEEK、PREEK；YAME）结尾，然后判断每个序列在美学（你喜欢这个押韵吗？）或技术（这个押韵完美吗？）方面。在顶叶电极中，N450 显示出在条件之间的押韵效应（即非押韵与全押韵；半押韵与全押韵；非押韵与半押韵），在两个群体中相似。然而，在前额中央电极中的并发活动在非说唱歌手中有左偏侧性，但在说唱歌手中没有。此外，非说唱歌手对这三种条件的反应在左侧半球电极的形态和幅度上存在差异，而在右侧半球电极上没有条件差异，而说唱歌手对他们认为不满意的半押韵的反应与左侧半球电极上的全押韵相似，与右侧半球电极上的非押韵相似。在等待序列中的第二个和第三个伪词时观察到的 CNV 反应在非说唱歌手的美学押韵判断任务中比在技术押韵判断任务中增强更多，这表明他们在美学押韵判断中投入了更多的努力。在说唱歌手中没有观察到任务效应，这表明美学和技术押韵判断可能对专家来说使用相同的过程。总的来说，我们的发现表明，即兴说唱的广泛实践可能会独特地鼓励大脑中语言和音乐特征综合处理的神经可塑性。
