Neural network model of on-off units in the fly visual system: simulations of dynamic behavior.
Neural network model of on-off units in the fly visual system: simulations of dynamic behavior.
复制标题
飞行视觉系统中开关单元的神经网络模型：动态行为的模拟。
DOI：
10.1007/s004220050444
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Ogmen,H
中科院分区：
文献类型：
--
作者：
Sarikaya,M;Wang,W;Ogmen,H
我们分析了一个神经网络模型的动态特性的开关尖峰神经元记录在第一视交叉的苍蝇视觉系统。该模型由两条平行的通路和三个连续的加工阶段组成。第一阶段模拟光感受器。在第二阶段，信号被分离成开启和关闭通路。这些途径被提出来对应于两个群体的无长突细胞。在第三阶段，开和关通路汇聚成开-关神经元。此外，根据该模型，开关神经元通过递归连接相互作用。该阶段被认为对应于L4层神经元。为了响应亮度的增量和减量，该模型表现出三分量响应，并为每个分量建议路径。当被一系列脉冲刺激时，该模型表现出对高于约5 Hz的频率的快速适应。此外，对开脉冲和关脉冲的适应独立地发生。当刺激频率降低时，该单元从其适应状态迅速恢复。时间调制传递函数在7 Hz附近具有其峰值。相位特性示出了对于低时间频率的相位超前变为对于高频率的相位滞后。这些模型的预测与Jansonius和货车Hateren（1991）的数据进行了比较。
We analyze the dynamic properties of a neural network model for on-off spiking neurons recorded in the first optic chiasm of the fly visual system. The model consists of two parallel pathways and three sequential processing stages. The first stage models photoreceptors. At the second stage, the signal is segregated into on- and off-pathways. These pathways are proposed to correspond to two populations of amacrine cells. At the third stage, the on- and off-pathways converge to on-off neurons. Furthermore, according to the model, on-off neurons interact via recurrent connections. This stage is proposed to correspond to lamina L4 neurons. In response to luminance increments and decrements, the model exhibits a three-component response and suggests pathways for each of the components. When stimulated by a train of pulses, the model exhibits fast adaptation for frequencies higher than about 5 Hz. Furthermore, adaptation to on- and off-pulses occurs independently. When the frequency of stimulation is reduced, the unit recovers rapidly from its adapted state. The temporal modulation transfer function has its peak around 7 Hz. The phase characteristics show a phase lead for low temporal frequencies changing to a phase lag for high frequencies. These model predictions are compared with data from Jansonius and van Hateren (1991).