Plasticity in the Structure of Visual Space.
Plasticity in the Structure of Visual Space.
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DOI：
10.1523/eneuro.0080-17.2017
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发表时间：
2017-05
期刊：
影响因子：
3.4
通讯作者：
Tononi G
中科院分区：
文献类型：
--
作者：
Song C;Haun AM;Tononi G
视觉空间包含了所有的视觉经验，但什么决定了视觉空间的地形结构仍然不清楚。在这里，我们测试一个新的理论框架，提出内在的横向连接在视觉皮层的视觉空间结构的机制。该框架表明，视觉皮层神经元之间的横向连接的强度塑造了视野中位置之间的空间相关性的体验。因此，横向连接强度的增加将导致感知相关性的增加和感知距离的收缩。为了通过人类心理物理学实验来测试这个框架，我们使用了赫布训练协议，在该协议中，两点刺激在视野中的不同位置同步闪现，以加强视觉皮层中两组不同神经元之间的横向连接。训练后，参与者在感知距离上经历了收缩。有趣的是，知觉收缩不仅发生在通过改变的连接直接连接的两个训练位置之间，而且发生在通过改变的连接间接连接的外部未训练位置之间。此外，如果两个训练位置太近或太远，超过横向连接的范围，训练效果会大大降低。这些研究结果表明，局部变化的横向连接的强度是足以改变视觉空间的地形结构。
Visual space embodies all visual experiences, yet what determines the topographical structure of visual space remains unclear. Here we test a novel theoretical framework that proposes intrinsic lateral connections in the visual cortex as the mechanism underlying the structure of visual space. The framework suggests that the strength of lateral connections between neurons in the visual cortex shapes the experience of spatial relatedness between locations in the visual field. As such, an increase in lateral connection strength shall lead to an increase in perceived relatedness and a contraction in perceived distance. To test this framework through human psychophysics experiments, we used a Hebbian training protocol in which two-point stimuli were flashed in synchrony at separate locations in the visual field, to strengthen the lateral connections between two separate groups of neurons in the visual cortex. After training, participants experienced a contraction in perceived distance. Intriguingly, the perceptual contraction occurred not only between the two training locations that were linked directly by the changed connections, but also between the outward untrained locations that were linked indirectly through the changed connections. Moreover, the effect of training greatly decreased if the two training locations were too close together or too far apart and went beyond the extent of lateral connections. These findings suggest that a local change in the strength of lateral connections is sufficient to alter the topographical structure of visual space.