Srinivasan M V, Jin Z F, Stange G, Ibbotson M R
Centre for Visual Sciences, Research School of Biological Sciences, Australian National University, Canberra.
Biol Cybern. 1993;68(3):199-207. doi: 10.1007/BF00224852.
A technique is described and tested for mapping the sensitivities and preferred directions of motion at different locations within the receptive fields of direction-selective motion-detecting visual neurons. The procedure is to record the responses to a number of visual stimuli, each stimulus presentation consisting of a set of short, randomly-oriented, moving bars arranged in a square grid. Each bar moves perpendicularly to its long axis. The vector describing the sensitivity and preferred direction of motion at each grid location is obtained as a sum of the unit vectors defining the directions of motion of the bars in each of the stimuli at that location, weighted by the strengths of the corresponding responses. The resulting vector field specifies the optimum flow field for the neuron. The advantage of this technique over the conventional approach of probing the receptive field sequentially at each grid location is that the parallel nature of the stimulus is sensitive to nonlinear interactions (such as shunting inhibition for mutual facilitation) between different regions of the visual field. The technique is used to determine accurately the motion receptive fields of direction-selective motion detecting neurons in the optic lobes of insects. It is potentially applicable to motion-sensitive neurons with highly structured receptive fields, such as those in the optic tectum of the pigeon or in area MST of the monkey.
本文描述并测试了一种技术，用于绘制方向选择性运动检测视觉神经元感受野内不同位置的敏感度和运动偏好方向。具体步骤是记录对多种视觉刺激的反应，每次刺激呈现由一组短的、随机定向的、以正方形网格排列的移动条组成。每个条沿其长轴垂直移动。通过将定义该位置每个刺激中条的运动方向的单位向量求和，并根据相应反应的强度加权，可得到描述每个网格位置运动敏感度和偏好方向的向量。由此产生的向量场确定了神经元的最佳流场。与在每个网格位置依次探测感受野的传统方法相比，该技术的优势在于刺激的并行性质对视野不同区域之间的非线性相互作用（如相互促进的分流抑制）敏感。该技术用于准确确定昆虫视叶中方向选择性运动检测神经元的运动感受野。它有可能应用于具有高度结构化感受野的运动敏感神经元，如鸽子视顶盖或猴子MST区中的神经元。
