Chan Kevin C, Murphy Matthew C, Bang Ji Won, Sims Jeffrey, Kashkoush Jasmine, Nau Amy C
Annu Int Conf IEEE Eng Med Biol Soc. 2018 Jul;2018:5519-5522. doi: 10.1109/EMBC.2018.8513622.
Visual cortex functionality in the blind has been shown to shift away from sensory networks toward task-positive networks that are involved in top-down modulation. However, how such modulation is shaped by experience and reflected behaviorally remains unclear. This study evaluates the visual cortex activity and functional connectivity among congenitally blind, acquired blind, and sighted subjects using blood-oxygenation-level-dependent functional MRI during sensory substitution tasks and at rest. We found that primary visual cortex activity due to active interpretation not only depends on the blindness duration, but also negatively associates with behavioral reaction time. In addition, alterations in visual and task-positive functional connectivity progress over the duration of blindness. In summary, this work suggests that functional plasticity in the primary visual cortex can be reshaped in the blind over time, even in the adult stage. Furthermore, the degree of top-down activity in the primary visual cortex may reflect the speed of performance during sensory substitution.
研究表明，盲人视觉皮层的功能已从感觉网络转向参与自上而下调制的任务积极网络。然而，这种调制如何由经验塑造并在行为上得到反映仍不清楚。本研究在感觉替代任务期间及静息状态下，使用血氧水平依赖性功能磁共振成像评估先天性盲人、后天性盲人及视力正常受试者的视觉皮层活动和功能连接。我们发现，主动解释引起的初级视觉皮层活动不仅取决于失明持续时间，还与行为反应时间呈负相关。此外，视觉和任务积极功能连接的改变会随着失明时间的延长而进展。总之，这项研究表明，即使在成年阶段，初级视觉皮层的功能可塑性也可随时间在盲人中重塑。此外，初级视觉皮层自上而下活动的程度可能反映感觉替代过程中的表现速度。
