Speech Neuroscience Lab, Department of Communication Sciences and Disorders, Arnold School of Public Health, University of South Carolina, Columbia, SC, United States.
Cortex. 2023 Sep;166:258-274. doi: 10.1016/j.cortex.2023.05.015. Epub 2023 Jun 20.
The oscillatory brain activities reflect neuro-computational processes that are critical for speech production and sensorimotor control. In the present study, we used neural oscillations in left-hemisphere stroke survivors with aphasia as a model to investigate network-level functional connectivity deficits associated with disrupted speech auditory feedback control. Electroencephalography signals were recorded from 40 post-stroke aphasia and 39 neurologically intact control participants while they performed speech vowel production and listening tasks under pitch-shifted altered auditory feedback (AAF) conditions. Using weighted phase-lag index, we calculated broadband (1-70 Hz) functional neural connectivity between electrode pairs covering the frontal, pre- and post-central, and parietal regions. Results revealed reduced fronto-central delta and theta band and centro-parietal low-beta band connectivity in left-hemisphere electrodes associated with diminished speech AAF compensation responses in post-stroke aphasia compared with controls. Lesion-mapping analysis demonstrated that stroke-induced damage to multi-modal brain networks within the inferior frontal gyrus, Rolandic operculum, inferior parietal lobule, angular gyrus, and supramarginal gyrus predicted the reduced functional neural connectivity within the delta and low-beta bands during both tasks in aphasia. These results provide evidence that disrupted neural connectivity due to left-hemisphere brain damage can result in network-wide dysfunctions associated with impaired sensorimotor integration mechanisms for speech auditory feedback control.
脑振荡活动反映了神经计算过程，这些过程对言语产生和感觉运动控制至关重要。在本研究中，我们使用左侧半球中风后失语症患者的神经振荡作为模型，研究与言语听觉反馈控制受损相关的网络级功能连接缺陷。我们记录了 40 名中风后失语症患者和 39 名神经学正常的对照组参与者的脑电图信号，他们在音高移位改变听觉反馈 (AAF) 条件下执行言语元音产生和听力任务。使用加权相位滞后指数，我们计算了覆盖额、额中和顶、顶区域的电极对之间的宽带（1-70 Hz）功能神经连接。结果表明，与对照组相比，左侧电极的额-中央 delta 和 theta 波段以及中央-顶低 beta 波段的连接减少，与中风后失语症患者的言语 AAF 补偿反应减弱有关。病变映射分析表明，额叶下回、岛盖部、下顶叶、角回和缘上回等多模态脑网络的中风诱导损伤，预测了失语症患者在两项任务中 delta 和低 beta 波段的功能神经连接减少。这些结果提供了证据，表明由于左半球脑损伤导致的神经连接中断会导致与言语听觉反馈控制受损的感觉运动整合机制相关的全网络功能障碍。
