Visual recognition and discrimination of random figures with black and white square cells

Abstract

The purpose of this study is to clarify quantitatively the relation of the physical nature of figures to the recognition and discrimination characteristics of vision when an observer views and perceives the form of two-dimensional figures. Thus, visual experiments are made by means of standard and test random figures composed of 12×12 square cells, some of which are painted black as picture elements. These figures are recognized and discriminated by several student observers with visual acuity not less than 0.8. Results obtained are as follows:
(1) Display time duration of 4 to 5 seconds is adequate for observers to recognize or discriminate the stimulus figures.
(2) Averaged number of additional or subtractive picture elements of test figures required to obtain a constant discrimination rate is proportional to the predetermined number of picture elements of the standard figure; i.e., the Weber ratio is constant.
(3) Test figures with picture elements of different spatial distributions are discriminated with different discrimination rates, even though the numbers of these elements are the same; i.e., the perceived psychological quantities of picture elements vary with their spatial positions.