Optimizing speech motor learning with neuromodulation: Behavioral outcomes and neural mechanisms

项目概要/摘要 中风是美国残疾的主要原因，经常导致语言障碍， 在专业、社会和家庭环境中的参与设置了障碍。虽然可以促进复苏， 在言语运动学习治疗中，残余残疾仍然是一个突出的问题。长期目标是 研究是通过结合以下方法来提高后天性言语障碍患者的干预效果： 理论指导的行为干预与有针对性的神经调节。其主要目标是 的建议是验证左腹前运动和运动皮层在言语运动学习中的作用， 建立经颅直流电刺激（tDCS）可以通过以下方式增强语言运动学习治疗 强化皮层语言网络。这项建议的中心假设是， 慢性中风可以通过刺激病灶周围的左腹侧运动前区和运动皮质来改善， 促进他们在语言运动学习治疗期间的参与，并加强皮层语言 网络通过联想学习。中心假设将通过追求三个具体目标来检验：1） 建立tDCS促进的言语运动学习的神经区域; 2）确定 主动tDCS与个体化电极放置可以增强言语运动学习干预 相对于具有言语失用症的受损说话者中的假tDCS;以及3）确定功能性tDCS， 与基于言语运动学习的干预相关的连接变化， 言语失用症的说话能力受损者。在第一个目标下，拟议的研究将系统地验证 左腹侧前运动和运动皮层在tDCS促进的言语运动学习中的作用 控制：电极极性、电极位置和有源电流的存在。对于第二个目标，单一- 受试者干预实验将用于评估tDCS增强失用症治疗的程度 结果，使用个性化的电流建模目标左腹前运动和运动皮质。第三 目的决定了目的2中的治疗条件可以改变功能连接的程度 通过静息态功能性神经成像测量。该研究是创新的，在申请人的 意见，因为它结合了基于实践的语音治疗与有针对性的tDCS，以加强赫布 可塑性，并衡量这种方法改变语音中功能连接的程度 网络这一研究对于建立言语运动的联合效能具有重要意义 学习治疗和tDCS在AOS，一个欠研究的条件。了解治疗的相互作用 神经调节将建立优化慢性中风恢复的能力，直接应用于 提高言语技能，提高沟通能力和生活质量。

PROJECT SUMMARY/ABSTRACT Stroke is a leading cause of disability in the United States, frequently leading to speech impairment that creates barriers to participation in professional, social, and family settings. While recovery can be promoted with speech motor learning treatment, residual disability remains a prominent issue. The long-term goal of this research is to enhance intervention outcomes for individuals with acquired speech impairment by combining theoretically-guided behavioral intervention with targeted neuromodulation. The main objectives of this proposal are to verify the role of left ventral premotor and motor cortices in speech motor learning and to establish that transcranial direct current stimulation (tDCS) can enhance speech motor learning treatment by strengthening the cortical speech network. The central hypothesis of this proposal is that speech recovery in chronic stroke can be improved by stimulating perilesional left ventral premotor and motor cortices, thereby promoting their engagement during speech motor learning treatment and strengthening the cortical speech network through associative learning. The central hypothesis will be tested by pursuing three specific aims: 1) Establish the neural regions that underlie tDCS-facilitated speech motor learning; 2) Determine the extent to which active tDCS with individualized electrode placement can enhance speech motor learning intervention relative to sham tDCS in impaired speakers with apraxia of speech; and 3) Determine the functional connectivity changes associated with speech motor learning-based intervention with active vs. sham tDCS in impaired speakers with apraxia of speech. Under the first aim, the proposed research will systematically verify the role of left ventral premotor and motor cortices in tDCS-facilitated speech motor learning using three controls: electrode polarity, electrode position, and presence of active current. For the second aim, single- subject intervention experiments will be used to evaluate the extent to which tDCS enhances apraxia treatment outcomes, using individualized current modeling to target left ventral premotor and motor cortices. The third aim determines the extent to which the treatment conditions in Aim 2 can change functional connectivity measured with resting-state functional neuroimaging. The proposed research is innovative, in the applicant's opinion, because it combines practice-based speech treatment with targeted tDCS to intensify Hebbian plasticity and measures the extent to which this approach changes functional connectivity in the speech network. This research will be significant because it will establish the combined effectiveness of speech motor learning treatment and tDCS in AOS, an understudied condition. Understanding the interaction of treatment and neuromodulation will build capacity to optimize chronic stroke recovery, with direct application to enhancing speech skills to improve communication ability and quality of life.