Mechanisms of experience-induced plasticity in the speech system in the adult human brain

成人大脑言语系统中经验诱发的可塑性机制

• 批准号: RGPIN-2019-06534
• 负责人: Tremblay, Pascale
• 金额: $ 2.4万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=684825
• 关键词: Mechanisms; experience; induced; plasticity; speech

The healthy adult brain retains a remarkable capacity to modify its structure and organization across the entire lifespan, following the acquisition of new skills, such as learning to speak a new language. This phenomenon is known as experience-dependent brain plasticity. Prior studies have suggested that repeated vocal activities, such as acting and television and radio broadcasting, can modify the neural organization of the brain systems that supports speech production. This results in enhanced vocal performance such as a better control of one's voice and more precise articulation. However, the neural mechanisms involved in the development of vocal expertise are still poorly understood. The objective of this program is to better understand the neurobiological correlates of non-musical vocal expertise (e.g. in television and radio broadcasters, actors and interpreters) in healthy young and older adults. This objective will be addressed via a series of studies using various methods including brain stimulation, magnetic resonance imaging (MRI) and measurements of biological compounds that have been associated with plasticity, such as glutamate and BDNF. In the first experiment, we will study the brain of healthy young and older adults with different levels of vocal expertise and compare it to the brain of healthy young and older adults with no vocal expertise, using molecular and MRI techniques. In subsequent studies, we will stimulate different parts of the brains of young and older non-experts to examine the effect that stimulation has on vocal control and brain chemistry. Because brain stimulation technologies are not yet optimized for the study of vocal expertise, we will test different protocols for inducing plasticity in the speech system and identify the one that produces the most significant changes in younger and older adults, which is important because the capacity for plasticity is known to decline with age. Using the knowledge generated in these studies, we will conduct a vocal training study combining molecular, MRI and brain stimulation methods to study plasticity induced by vocal experience. We will recruit three groups of healthy adults with no vocal expertise and train them for 4 weeks, twice a week, using a combination of vocal control, speech rate and articulation exercises. One of the groups will receive only the training. The other group will receive only brain stimulation. The third group will receive both. It is expected that the group receiving both will show the most evidence of vocal learning, behaviourally (better vocal performance) and in the brain, measured with molecular and MRI techniques. This research program will advance current knowledge of experience-induced plasticity mechanisms in the healthy aging human brain. This knowledge will contribute to the development of brain-enhancing technologies, cognitive training and cognitive stimulation applications, which are being developed and patented across the world.

在获得新技能（例如学习说新语言）之后，健康的成年大脑保留了在整个生命周期中修改其结构和组织的显着能力。这种现象被称为经验依赖性的大脑可塑性。先前的研究表明，反复的声乐活动，例如表演，电视和无线电广播，可以改变支持语音生产的大脑系统的神经组织。这会提高声音表现，例如更好地控制自己的声音和更精确的发音。但是，涉及声音专业知识发展的神经机制仍然很少了解。该计划的目的是更好地了解健康的年轻和老年人中非音乐发声专业知识的神经生物学相关性（例如，电视和无线电广播，演员和口译员）。该目标将通过一系列研究来解决各种方法，包括大脑刺激，磁共振成像（MRI）以及与可塑性相关的生物化合物（例如谷氨酸和BDNF）的测量。在第一个实验中，我们将研究具有不同人声专业知识的健康和老年人的大脑，并使用分子和MRI技术将其与没有人声专业知识的健康的年轻和老年人的大脑进行比较。在随后的研究中，我们将刺激年轻和年长的非专家大脑的不同部分，以检查刺激对声带控制和脑化学的影响。由于脑刺激技术尚未针对人声专业知识的研究进行优化，因此我们将测试不同方案以诱导语音系统的可塑性，并确定在年轻和老年人中产生最重大变化的方案，这很重要，因为已知可塑性的能力随着年龄的增长而下降。使用这些研究中产生的知识，我们将进行一项声音训练研究，结合了分子，MRI和脑刺激方法，以研究由人声体验引起的可塑性。我们将使用声音控制，语音率和发音练习的组合，招募三组健康的成年人，没有人声专业知识，并每周两次训练他们4周，两次。其中一个小组将仅接受培训。另一组只会接受大脑刺激。第三组将两者都接受。预计接受两者的群体将表现出最大的声音学习证据，行为（更好的人声表现）以及以分子和MRI技术来衡量的大脑。该研究计划将提高对健康衰老的人脑的经验诱导的可塑性机制的了解。这些知识将有助于开发脑增强技术，认知训练和认知刺激应用，这些应用已在世界范围内开发和专利。