增强反向抑制的视觉训练在脑卒中后偏盲视觉功能恢复中的作用和神经电生理机制

视野缺损（即偏盲）常见于脑卒中所致的单侧初级视皮层损伤。新近研究发现，视觉训练是治疗偏盲的理想方法。本课题组首次提出"增强反向抑制"的新型视觉训练疗法。与增强损伤侧视皮层兴奋性的传统疗法相比，我们推测新型疗法将增强损伤侧对完整侧的抑制作用，有助于皮层间抑制性回路的建立，显著提高偏盲的疗效。在前期的一系列神经电生理研究中，我们发现正常成人的视觉训练同时伴随高级注意相关皮层活动的减弱和低级视皮层活动的增强。我们推测偏盲的视觉训练也涉及高级皮层和低级视皮层的拮抗作用，而增强反向抑制的视觉训练正是通过强化这种拮抗作用，促进了偏盲视觉功能的恢复。为了证实上述假说，我们将结合心理物理学手段和神经电生理技术，从行为-脑活动两个层面，观察新型和传统视觉训练的疗效差异，及其高级皮层和低级视皮层活动变化模式的异同。本课题将从新的视角阐明脑卒中后偏盲视觉功能恢复的脑机制，并为优化偏盲的临床治疗提供新思路。

Visual field loss (i.e., hemianopia) is common after stroke, which was due to damaged unilateral primary visual cortex. Recent research revealed that visual training is a potential treatment for hemianopia. We propose a novel visual training paradigm aimed to enhance intracortical inhibitions, which is expected to be superior to traditional visual restoration training methods. In our previous electrophysiological studies, we found that visual training in normal adults led to reduced activities in higher cortices, in parallel with enhanced activities in lower visual cortical regions. Such opponent process may be involved in visual restoration training of hemianopia. We speculated that our new training regime may promote rehabilitation of hemianopia through strengthening the opponent process between higher cortical areas and visual cortices. In present research, using combined psychophysical and electrophysiological techniques, we investigate the differences between new and traditional training methods, not only at behavioral restoration effects, but also at brain activity change patterns of higher and lower cortical areas. Our research will clarify the neural mechanisms underlying restoration of poststroke hemianopia by visual training from a new perspective, and provide a new direction to improve treatment efficacy.