Center for Brain & Cognition, Universitat Pompeu Fabra, Barcelona, Catalunya, Spain.
Department of Psychology, Harvard University, Cambridge, Massachusetts, United States of America.
PLoS One. 2021 Dec 1;16(12):e0260728. doi: 10.1371/journal.pone.0260728. eCollection 2021.
In western music, harmonic expectations can be fulfilled or broken by unexpected chords. Musical irregularities in the absence of auditory deviance elicit well-studied neural responses (e.g. ERAN, P3, N5). These responses are sensitive to schematic expectations (induced by syntactic rules of chord succession) and veridical expectations about predictability (induced by experimental regularities). However, the cognitive and sensory contributions to these responses and their plasticity as a result of musical training remains under debate. In the present study, we explored whether the neural processing of pure acoustic violations is affected by schematic and veridical expectations. Moreover, we investigated whether these two factors interact with long-term musical training. In Experiment 1, we registered the ERPs elicited by dissonant clusters placed either at the middle or the ending position of chord cadences. In Experiment 2, we presented to the listeners with a high proportion of cadences ending in a dissonant chord. In both experiments, we compared the ERPs of musicians and non-musicians. Dissonant clusters elicited distinctive neural responses (an early negativity, the P3 and the N5). While the EN was not affected by syntactic rules, the P3a and P3b were larger for dissonant closures than for middle dissonant chords. Interestingly, these components were larger in musicians than in non-musicians, while the N5 was the opposite. Finally, the predictability of dissonant closures in our experiment did not modulate any of the ERPs. Our study suggests that, at early time windows, dissonance is processed based on acoustic deviance independently of syntactic rules. However, at longer latencies, listeners may be able to engage integration mechanisms and further processes of attentional and structural analysis dependent on musical hierarchies, which are enhanced in musicians.
在西方音乐中，和声的预期可以通过意想不到的和弦来实现或打破。在没有听觉偏差的情况下，音乐的不规则性会引起经过充分研究的神经反应（例如 ERAN、P3、N5）。这些反应对图式预期（由和弦接续的句法规则引起）和关于可预测性的真实预期（由实验规则引起）敏感。然而，这些反应的认知和感官贡献及其由于音乐训练而产生的可塑性仍然存在争议。在本研究中，我们探讨了纯声学违规的神经处理是否受图式和真实预期的影响。此外，我们还研究了这两个因素是否与长期的音乐训练相互作用。在实验 1 中，我们记录了在和弦进行的中间或结尾位置放置不和谐音簇时产生的 ERPs。在实验 2 中，我们向听众呈现了高比例以不和谐和弦结尾的终止式。在这两个实验中，我们比较了音乐家和非音乐家的 ERPs。不和谐音簇引起了独特的神经反应（早期负性、P3 和 N5）。虽然 EN 不受句法规则的影响，但 P3a 和 P3b 对于不和谐终止式比中间不和谐和弦更大。有趣的是，这些成分在音乐家中比在非音乐家中更大，而 N5 则相反。最后，我们实验中不和谐终止式的可预测性没有调制任何 ERPs。我们的研究表明，在早期时间窗口中，不和谐音是基于声学偏差进行处理的，而与句法规则无关。然而，在较长的潜伏期内，听众可能能够参与基于音乐层次结构的整合机制和进一步的注意力和结构分析过程，这些过程在音乐家中得到增强。
