Influence of the figure configuration upon the contrast of brightness--with the changes in the luminous reflectance of the figure

Abstract

The purpose of the present investigation is to study the effect of the figure configuration upon the brightness contrast by testing how the phenomenal brightness of a small gray patch placed within or outside the figure changes with (a) the differences in configuration, and (b) locations of the small patch, when the brightness contrast between the figure and the background is kept constant. The author took a field-theoretical approach.The apparatus is shown by Fig. 1 in the text. Method of adjustment was used. First under two conditions, (i.e., the black figure on the white background, and the white figure on the black background, ) the gray patch was placed, (1) near the angle, near the side, and in the center within the same figure (a square, a regular triangle and a circle), (2) in the center of the same figure but with three different sizes. Secondly, for the purpose of studying more closely the changing process of the phenomenal brightness of the gray patch, its location was changed gradually within and outside the figure (a square, a regular triangle and a circle).The results may be summarized as follows: (1) the field-force has an effect of making the gray patch darker, when the patch is placed within the black solid figure on the white background, (2) it has also an effect of making the patch brighter, when it is placed within the white solid figure on the black background and (3) the phenomenal brigntness of the gray patch changes in proportion to the fieldforce, and its changing process roughly corresponds with that based on light threshold value. These results may suggest that the effect of the figure configuration upon the brightness contrast can be explained and predicted quantitatively from the viewpoint of the field-force.