Department of Rehabilitation and Movement Sciences, University of Medicine and Dentistry of New Jersey, Newark, NJ 07107, USA.
IEEE Trans Neural Syst Rehabil Eng. 2013 Mar;21(2):198-207. doi: 10.1109/TNSRE.2013.2238250. Epub 2013 Jan 9.
We investigated neural effects of visuomotor discordances during visually-guided finger movements. A functional magnetic resonance imaging (fMRI)-compatible data glove was used to actuate (in real-time) virtual hand models shown on a display in first person perspective. In Experiment 1, we manipulated virtual hand motion to simulate either hypometric or unintentional (actuation of a mismatched finger) feedback of sequential finger flexion in healthy subjects. Analysis of finger motion revealed no significant differences in movement behavior across conditions, suggesting that between-condition differences in brain activity could only be attributed to varying modes of visual feedback rather than motor output. Hypometric feedback and mismatched finger feedback (relative to veridical) were associated with distinct activation. Hypometric feedback was associated with activation in the contralateral motor cortex. Mismatched feedback was associated with activation in bilateral ventral premotor, left dorsal premotor, and left occipitotemporal cortex. The time it took the subject to evaluate visuomotor discordance was positively correlated with activation in bilateral supplementary motor area, bilateral insula, right postcentral gyrus, bilateral dorsal premotor areas, and bilateral posterior parietal lobe. In Experiment 2, we investigated the effects of hypo- and hypermetric visual feedback in three stroke subjects. We observed increased activation of ipsilesional motor cortex in both hypometric and hypermetric feedback conditions. Our data indicate that manipulation of visual feedback of one's own hand movement may be used to facilitate activity in select brain networks. We suggest that these effects can be exploited in neurorehabilition to enhance the processes of brain reorganization after injury and, specifically, might be useful in aiding recovery of hand function in patients during virtual reality-based training.
我们研究了在视觉引导手指运动期间视动不一致的神经效应。使用功能磁共振成像 (fMRI) 兼容的数据手套实时驱动显示在第一人称视角下的虚拟手模型。在实验 1 中，我们操纵虚拟手运动，模拟健康受试者中连续手指弯曲的欠距或非故意（驱动不匹配的手指）反馈。手指运动分析显示，在不同条件下的运动行为没有明显差异，这表明大脑活动中的条件差异只能归因于不同的视觉反馈模式，而不是运动输出。欠距反馈和不匹配手指反馈（相对于真实反馈）与不同的激活相关。欠距反馈与对侧运动皮层的激活相关。不匹配反馈与双侧腹侧运动前区、左侧背侧运动前区和左侧枕颞叶皮层的激活相关。受试者评估视动不一致所需的时间与双侧辅助运动区、双侧岛叶、右侧中央后回、双侧背侧运动前区和双侧顶叶后区的激活呈正相关。在实验 2 中，我们在三名中风患者中研究了欠距和超距视觉反馈的影响。我们观察到在欠距和超距反馈条件下同侧运动皮层的激活增加。我们的数据表明，对手的自身手部运动的视觉反馈的操纵可用于促进特定脑网络的活动。我们认为，这些效应可在神经康复中加以利用，以增强损伤后的大脑重组过程，特别是在虚拟现实训练中对手部功能恢复可能有用。
