Brain mechanisms of auditory-motor integration and learning

视觉-运动整合的大脑网络得到了很好的研究，产生了视觉行动的背侧流模型，在该模型中，来自视觉区域的信息在顶叶皮质中转换，并被馈送到运动前区域以计划运动反应。研究人员现在正在探索将听觉感知和运动反应联系起来的神经机制，特别是音乐和语言。有人认为，背流中的特定通路将听觉信息和运动计划联系在一起，承担着说话或演奏乐器所需的前馈和反馈控制。*我们已经证明，即使对于没有接受过训练的人来说，运动区域-包括运动前皮质(PMC)和基底节(BG)-在听音乐时也是活跃的。我们还知道，简单地听一听与运动顺序一致的旋律就可以促进学习。这些发现表明，听觉系统和运动系统之间存在内在的相互作用。此外，我们已经证明，在学习新旋律时，用于计算视觉-运动转换的顶区是参与的。最后，有证据表明，BG的不同区域对于音乐节奏的预测和愉悦是重要的。*这项拟议研究的目标是在学习背景下测试听觉、运动和纹状体区域及其相互作用对听觉-运动整合的贡献。*目标1：将使用功能磁共振成像和经颅磁共振仪评估听觉和运动区域对纯听觉训练的运动学习的贡献。我们假设，旋律学习将导致一致的运动序列的增强表现，以及听觉、PMC和顶区活动的更大耦合。TMS将测试PMC在获得听觉-运动联系方面的作用，这些联系被认为是从听觉学习转移到运动学习的基础。*目标2：功能磁共振将用于调查熟练和新手音乐家如何使用听觉和运动信息来学习新旋律。我们假设，当音乐家学习时，他们首先利用PMC和小脑前馈机制来提高准确性，然后利用基于听觉和顶叶的反馈机制来微调演奏。相比之下，新学习者更依赖于运动信息和反馈控制。*目标3：行为学和功能磁共振实验将测试PMC和特定的BG在音乐节奏背景下的时间预测和奖励加工中的作用。我们假设PMC对于提取时间规律性是重要的，一旦识别出规律性模式，壳核就参与预测。此外，我们假设腹侧纹状体的背侧部分与音乐节拍的愉悦和奖励有关。*这项工作将产生关于声音和运动整合背后的大脑机制的重要新信息，并将对基于视觉的听觉-运动整合的背流理论进行关键测试。

The brain networks for visual-motor integration are well studied, producing the dorsal stream model of vision for action in which information from visual areas is transformed in parietal cortex, and fed to premotor regions to plan a motor response. Researchers are now exploring the neural mechanisms linking auditory perception and motor response, particularly for music and speech. It is proposed that specific pathways in the dorsal stream link auditory information and motor plans, underwriting the feed-forward and feedback control required for speaking or playing an instrument. ***   We have shown that even for people with no training, motor regions - including the premotor cortex (PMC) and basal ganglia (BG) - are active when listening to music. We also know that simply listening to melodies that are congruent with a motor sequence can facilitate learning. These findings suggest that there are intrinsic interactions between the auditory and motor systems. Further, we have shown that parietal regions known to compute visual-motor transformations are engaged when learning new melodies. Finally, there is evidence that different regions of the BG are important for prediction and pleasure for musical rhythm. ***The goal of the proposed research is to test the contributions of auditory, motor and striatal regions - and their interactions - to auditory-motor integration in the context of learning.*** ***Aim 1: fMRI and TMS will be used to assess the contributions of auditory and motor regions to motor learning with purely auditory training. We hypothesize that melody learning will lead to enhanced performance of a congruent motor sequence and greater coupling of activity in auditory, PMC and parietal regions. TMS will test the role of PMC in acquiring the auditory-motor associations thought to underlie transfer from auditory to motor learning. ***Aim 2: fMRI will be used to investigate how skilled and novice musicians use auditory and motor information to learn new melodies. We hypothesize that when musicians learn they first engage PMC and cerebellar feed-forward mechanisms to improve accuracy, and later engage auditory and parietal based feedback mechanisms to fine-tune performance. In contrast, new learners rely more on motor information and feedback control.***Aim 3: Behavioral and fMRI experiments will test the role of the PMC and specific BG in temporal prediction and reward processing in the context of musical rhythm. We hypothesize that PMC is important for extracting temporal regularity and that the putamen is engaged in prediction once a regular pattern is identified. Further, we hypothesize that the dorsal part of the ventral striatum is involved in pleasure and reward for musical beat. ***This work will generate important new information about the brain mechanisms underlying the integration of sound and movement, and will provide a critical test of dorsal stream theories of auditory-motor integration based on vision.*** ***********