Center of Functionally Integrative Neuroscience, University of Aarhus, Danish Neuroscience Center, Aarhus University Hospital, Nørrebrogade 44 Building 10G-5, 8000 Aarhus, Denmark.
Brain Res. 2011 May 10;1389:103-14. doi: 10.1016/j.brainres.2011.02.089. Epub 2011 Mar 5.
The human brain is constantly predicting the auditory environment by representing sequential similarities and extracting temporal regularities. It has been proposed that simple auditory regularities are extracted at lower stations of the auditory cortex and more complex ones at other brain regions, such as the prefrontal cortex. Deviations from auditory regularities elicit a family of early negative electric potentials distributed over the frontal regions of the scalp. In this study, we wished to disentangle the brain processes associated with sequential vs. hierarchical auditory regularities in a musical context by studying the event-related potentials (ERPs), the behavioral responses to violations of these regularities, and the localization of the underlying ERP generators using two different source analysis algorithms. To this aim, participants listened to musical cadences constituted by seven chords, each containing either harmonically congruous chords, harmonically incongruous chords, or harmonically congruous but mistuned chords. EEG was recorded and multiple source analysis was performed. Incongruous chords violating the rules of harmony elicited a bilateral ERAN, whereas mistuned chords within chord sequences elicited a right-lateralized MMN. We found that the dominant cortical sources for the ERAN were localized around Broca's area and its right homolog, whereas the MMN generators were localized around the primary auditory cortex. These findings suggest a predominant role of the auditory cortices in detecting sequential scale regularities and the posterior prefrontal cortex in parsing hierarchical regularities in music.
人类大脑通过表示序列相似性和提取时间规律来不断预测听觉环境。有人提出，简单的听觉规律在听觉皮层的较低部位被提取，而更复杂的规律则在大脑的其他区域，如前额叶皮层被提取。听觉规律的偏差会引起一系列早期负电潜力，分布在头皮的额区。在这项研究中，我们希望通过研究事件相关电位（ERP）、对这些规律违反的行为反应以及使用两种不同的源分析算法对潜在 ERP 发生器的定位，来区分与音乐背景下序列和层次听觉规律相关的大脑过程。为此，参与者听由七个和弦组成的音乐终止式，每个和弦都包含和声一致的和弦、和声不一致的和弦或和声一致但音准不对的和弦。记录 EEG 并进行多次源分析。违反和声规则的不和谐和弦会引起双侧 ERAN，而和弦序列中的音准不对的和弦会引起右侧 MMN。我们发现，ERAN 的主要皮质源位于布罗卡区及其右侧同源区，而 MMN 的发生器位于初级听觉皮层周围。这些发现表明，听觉皮层在检测序列音阶规律方面起着主导作用，而后前额叶皮层在解析音乐中的层次规律方面起着主导作用。
