Abstract
Man has an excellent function of pattern recognition, where as he has an undesirable function such as optical illusion. These excellence and defect are supposed to be the double faced characteristics derived from the nervous configuration of the visual system. Therefore, if the quantitative analysis into the relation between the optical illusion and the nervous configuration is possible, a clue will be obtained to the specific mechanism of human pattern recognition.
In this paper, Müller-Lyer and Poggendorff optical illusions are examined as examples and quantitative measurements are performed for the extent of illusion in about a hundred human subjects. A mathematical model for the mechanism of the optical illusion is also proposed here and its validity is discussed on the basis of the results of subjective measurement.
The concept of this model consists of two parts. The first is a spatial filter which picks up the properties of two dimensional optical images and the second is the constitution to perform higher recognition. The former corresponds to the retina and the lateral geniculate body in the physiological field, and the function is simulated by a constitution of the lateral inhibition according to the physiological results. The latter corresponds to the visual cortex, in which patterns may be recognized by the maximum output of the spatial filter.
The value of each parameter of this model is given to fit the results of subjective measurement. Comparison of the present results with these from a different method of parameter decision using gratings of sinusoidal brightness level as stimulus reported by the other authors is also discussed.
