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

点击翻译按钮获取中文摘要

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.