视网膜神经节细胞感受野的一种新模型 I.含大周边的感受野模型

A NEW COMPUTATIONAL MODEL OF RETINAL GANGLION CELLRECEPTIVE FIELDS I.A MODEL OF GANGLION CELL RECEPTIVE FIELDS WITHEXTENDED DISINHIBITORY AREA

感受野是视觉系统信息处理的基本结构和功能单元。X、Y细胞是两类主要的视网膜神经节细胞。生理实验发现,在经典感受野之外还存在一个大范围的大周边去抑制区。文中采用周边去抑制区对经典外周的去抑制非线性作用方式 ,建立一个二维的与实验结果联系紧密的X、Y细胞统一的复合感受野模型。该模型不仅能模拟X细胞的null -test反应和Y细胞的on -off反应 ,还模拟了Y细胞在低空频刺激时的倍频反应、圆面积反应曲线、感受野空间频率调谐曲线。文中用空间滤波器的观点解释了X、Y细胞空间滤波特性的不同 ,同时指出大周边去抑制区的存在 ,在有效抑制感受野低频反应上起着重要作用。

Receptive field (RF) is the basic structural and functional unit for signal processing in visual system. X cell and Y cell are two main kinds of retinal ganglion cell. It was shown that there is a large disinhibitory area outside the classical receptive field. Inspired by the unified X and Y cell model proposed by P. Gaudiano, we build a two dimensional model with nonlinear interaction between the large disinhibitory area and the inhibitory surround. We simulated the null-test response of the X cell and the on-off response of the Y cell, spot area response curves and spatial frequency tuning curves of the X and Y cells. Then we used filter theory to explain the difference between X and Y cell's spatial property and discussed effect of the large disinhibitory area on the spatial property of classical receptive field.