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，经常导致言语障碍 对参与职业、社会和家庭环境造成障碍。虽然可以促进康复 在言语运动学习治疗中，残余残疾仍然是一个突出问题。本次活动的长远目标 研究旨在通过结合以下方法来增强对获得性言语障碍患者的干预结果 理论指导的有针对性的神经调节行为干预。本次活动的主要目标 建议验证左腹侧前运动皮质和运动皮质在言语运动学习中的作用，并 确定经颅直流电刺激 (tDCS) 可以通过以下方式增强言语运动学习治疗 加强皮质言语网络。该提案的中心假设是言语恢复 通过刺激病灶周围的左腹侧前运动皮质和运动皮质可以改善慢性中风，从而 促进他们在言语运动学习治疗期间的参与并加强皮质言语 通过联想学习建立网络。将通过追求三个具体目标来检验中心假设：1） 建立 tDCS 促进的言语运动学习背后的神经区域； 2) 确定程度 主动 tDCS 与个性化电极放置可以增强言语运动学习干预 相对于患有言语失用的受损说话者的假 tDCS； 3）确定功能 与基于言语运动学习的干预（主动与假 tDCS）相关的连接变化 说话者有言语失用症。在第一个目标下，拟议的研究将系统地验证 左腹侧运动前皮层和运动皮层在 tDCS 促进的言语运动学习中的作用，使用三种 控制：电极极性、电极位置和有功电流的存在。对于第二个目标，单 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，使用个体化电流模型来针对左腹侧运动前皮层和运动皮层。第三个 目标确定目标 2 中的治疗条件可以改变功能连接的程度 通过静息态功能神经影像进行测量。拟议的研究具有创新性，在申请人看来 意见，因为它将基于实践的言语治疗与有针对性的 tDCS 结合起来，以强化 Hebbian 可塑性并衡量这种方法改变语音功能连接的程度 网络。这项研究意义重大，因为它将建立言语运动的综合有效性 学习 AOS 的治疗和经颅直流电刺激 (tDCS)，这是一种尚未得到充分研究的疾病。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，并直接应用于 增强言语技巧，以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.