UCL Ear Institute, University College London, London WC1X 8EE, UK.
Otto Hahn Research Group Neural Bases of Intonation in Speech and Music, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 04103, Germany.
Cereb Cortex. 2022 Sep 4;32(18):3878-3895. doi: 10.1093/cercor/bhab454.
Complex sequential behaviors, such as speaking or playing music, entail flexible rule-based chaining of single acts. However, it remains unclear how the brain translates abstract structural rules into movements. We combined music production with multimodal neuroimaging to dissociate high-level structural and low-level motor planning. Pianists played novel musical chord sequences on a muted MR-compatible piano by imitating a model hand on screen. Chord sequences were manipulated in terms of musical harmony and context length to assess structural planning, and in terms of fingers used for playing to assess motor planning. A model of probabilistic sequence processing confirmed temporally extended dependencies between chords, as opposed to local dependencies between movements. Violations of structural plans activated the left inferior frontal and middle temporal gyrus, and the fractional anisotropy of the ventral pathway connecting these two regions positively predicted behavioral measures of structural planning. A bilateral frontoparietal network was instead activated by violations of motor plans. Both structural and motor networks converged in lateral prefrontal cortex, with anterior regions contributing to musical structure building, and posterior areas to movement planning. These results establish a promising approach to study sequence production at different levels of action representation.
复杂的序列行为，如说话或演奏音乐，需要灵活的基于规则的单一行为的链接。然而，大脑如何将抽象的结构规则转化为运动仍然不清楚。我们将音乐制作与多模态神经影像学相结合，以区分高级结构和低级运动规划。钢琴家通过在屏幕上模仿模型手，在静音的磁共振兼容钢琴上演奏新的音乐和弦序列。和弦序列在音乐和声和上下文长度方面进行了操作，以评估结构规划，在演奏手指方面进行了操作，以评估运动规划。概率序列处理模型证实了和弦之间的时间扩展依赖关系，而不是运动之间的局部依赖关系。结构计划的违反激活了左侧额下回和中颞叶回，并且连接这两个区域的腹侧通路的各向异性分数与结构规划的行为测量呈正相关。相反，违反运动计划会激活双侧额顶叶网络。结构和运动网络都汇聚在外侧前额叶皮层中，前部区域有助于音乐结构的构建，后部区域有助于运动规划。这些结果为研究不同水平的动作表示的序列产生提供了一种很有前途的方法。
