A theoretical analysis of the influence of fixational instability on the development of thalamocortical connectivity.
A theoretical analysis of the influence of fixational instability on the development of thalamocortical connectivity.
复制标题
固定不稳定性对丘脑皮质连接发展影响的理论分析。
DOI：
10.1162/089976606775623270
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Rucci,Michele
中科院分区：
文献类型：
--
作者：
Casile,Antonino;Rucci,Michele
在自然观看条件下，视觉固定的生理不稳定性使刺激在视网膜上的投射保持恒定的运动。睁眼后，长期暴露于不断移动的视网膜图像可能会影响细胞反应特征的依赖于经验的细化。先前的建模研究结果表明，固定不稳定性对 V1 简单细胞感受野的 Hebbian 成熟有贡献（Rucci、Edelman 和 Wray，2000；Rucci 和 Casile，2004）。这封信探讨了这种贡献的起源。使用外侧膝状核单位和 V1 简单细胞的拟线性模型，我们推导出睁眼前后丘脑皮质活动二阶统计的解析表达式。我们表明，在存在自然刺激的情况下，注视不稳定性会在视网膜输入中引入空间不相关的信号，这会强烈影响模型中相关活动的结构。该输入信号产生类似于睁眼前的丘脑皮质活动状态，并且与皮质感受野的赫布成熟相一致。
Under natural viewing conditions, the physiological instability of visual fixation keeps the projection of the stimulus on the retina in constant motion. After eye opening, chronic exposure to a constantly moving retinal image might influence the experience-dependent refinement of cell response characteristics. The results of previous modeling studies have suggested a contribution of fixational instability to the Hebbian maturation of the receptive fields of V1 simple cells (Rucci, Edelman, & Wray, 2000; Rucci & Casile, 2004). This letter examines the origins of such a contribution. Using quasilinear models of lateral geniculate nucleus units and V1 simple cells, we derive analytical expressions for the second- order statistics of thalamocortical activity before and after eye opening. We show that in the presence of natural stimulation, fixational instability introduces a spatially uncorrelated signal in the retinal input, which strongly influences the structure of correlated activity in the model. This input signal produces a regime of thalamocortical activity similar to that present before eye opening and compatible with the Hebbian maturation of cortical receptive fields.