Development of a highly controllable visual stimulus generator for multidimentional analysis of visual processing

在视觉系统研究中，准确确定平行通道的时空特性是非常重要的。理想情况下，视觉刺激设备应该以可重复和高度可控的方式呈现广泛的视觉刺激，以便测试尽可能多的控制视觉通道响应的重要视觉参数。在这项研究中，我们开发了一种多功能视觉刺激发生器，它结合了现有技术的大多数优点。图像由任意方向和大小的图案组成。每个图像的大小、位置、方向、强度和颜色都可以很容易地调整，并且图像可以以所需的速度和距离向任何方向移动。此外，刺激运动和持续时间是由函数发生器和计算机外部控制的。由于图像参数是外部可控的，该设备在工作站(SPARK STATION；SUN MicroSystems)的辅助下用于通道时空特性的定量参数测量。该计算机程序已被开发用于执行视觉性能的多维分析，作为视觉图像配置、位置、运动、强度或其他参数的函数。利用该设备，我们对视觉错觉进行了心理物理测量，包括主观轮廓和明显的运动知觉，并在这些心理物理发现与最近的解剖和生理发现之间提供了一些概念性的联系。

The accurate determination of the spatio-temporal properties of parallel channels is of central importance in the study of visual system. Ideally a visual stimulation device should present in a repeatable and highly controllable manner, a wide range of a visual stimuli, in order to test as many as possible important visual parameters controlling the response of a visual channel.In this study we have developed a versatile visual stimulation generator which incorporates most of the advantages of the existing techniques. Images consist of patterns of any desired orientation and size. The size, position, orientation, intensity, and color of each image is readily adjustable, and images can be moved in any direction at a desire rate and distance. In addition, stimulus movement 'and duration are externally controlled by function generators and a computer. Because image parameters are externally controllable, the device has been useful in quantitative para'metric measurements of spatio-temporal properties of channels with the aid of a work station(SPARKstation ; SUN microsystems). The computer program has been developed to perform a multidimensional analysis of visual performance as a function of visual image configuration, position, movement, intensity, or other parameter. With this apparatus we have carried out psychophysical measurements on visual illusions, involving subjective contours and apparent motion perception, and provided some conceptual links between these psychophysical findings and the recent anatomical and physiological discoveries.