Contrast response in a comprehensive network model of macaque V1
Contrast response in a comprehensive network model of macaque V1
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DOI：
10.1167/jov.20.4.16
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发表时间：
2020-04-01
影响因子：
1.8
通讯作者：
Young, Lai-Sang
中科院分区：
文献类型：
--
作者：
Chariker, Logan;Shapley, Robert;Young, Lai-Sang
对对比度的反应是猕猴初级视觉皮层 V1 最重要的功能之一，但迄今为止还没有足够的理论来解释它。为了填补我们对皮质功能理解的这一空白，我们构建并分析了猕猴 V1 的输入层 4C alpha 的新的大规模生物约束模型。我们将新型号称为CSY2。我们用对比度、方向和空间频率各不相同的三参数视觉刺激系列来挑战 CSY2。 CSY2准确地模拟了实验数据并做出了许多新的预测。它解释了 1) 放电率与对比度函数的形状，2) 方向和空间频率调谐与对比度的关系，以及 3) 皮质活动图的近似对比度不变性。后期分析表明，成功模拟对比反应所需的机制包括强烈的周期性兴奋和抑制，以找到整个皮质表面的动态平衡、L6 和 L4 之间的动态反馈以及抑制性突触抑制等突触动力学。
The response to contrast is one of the most important functions of the macaque primary visual cortex, V1, but up to now there has not been an adequate theory for it. To fill this gap in our understanding of cortical function, we built and analyzed a new large-scale, biologically constrained model of the input layer, 4C alpha, of macaque V1. We called the new model CSY2. We challenged CSY2 with a three-parameter family of visual stimuli that varied in contrast, orientation, and spatial frequency. CSY2 accurately simulated experimental data and made many new predictions. It accounted for 1) the shapes of firing-rate-versus-contrast functions, 2) orientation and spatial frequency tuning versus contrast, and 3) the approximate contrast-invariance of cortical activity maps. Post-analysis revealed that the mechanisms that were needed to produce the successful simulations of contrast response included strong recurrent excitation and inhibition that find dynamic equilibria across the cortical surface, dynamic feedback between L6 and L4, and synaptic dynamics like inhibitory synaptic depression.