Geometical Optical Illusions Generated by Helmholtz Squares

• Yoshioka Tohru

  Otuma Women's University

• Ichihara Shigeru

  Tokyo-toritsu University

• Susami Norifumi

  Chukyo University

Bibliographic Information

Other Title

• ヘルムホルツの正方形における幾何学的錯視

Abstract

If we look at two patterns of identical size, one made up of vertical stripes and the other of horizontal, the former will appear wider than it really is, while the latter will appear taller. This known as the Helmholtz Square Illusion, and can be consider one example of the illusion of sectioned distance. In the present investigation, striped patterns were used to investigate the effect of both the spatial frequency and black/white duty of stripes upon the Helmholtz Square Illusion. The striped stimuli in this study were shown upon a CRT, and the experiment as a whole was under the control of an computer. Combinations of the four spatial frequency factors, three duty factors, and two stripe-orientation factors used in the experiment resulted in a total of 4×3×2=24 different stimuli. The experiment confirmed that horizontally-striped squares appeared taller, and vertically-striped squares appeared wider. 'A spatial frequency of 2 c/deg produced the greatest degree of illusion in horizontally-striped squares, while a spatial frequency of 0.5 c/deg produced the greatest degree of illusion in vertically-striped squares 0.5 c/deg. A decrease in the white component of the duty produced some lessening of the degree of illusion, but this was not of a significant level.

Journal

• Bulletin of Japanese Society for the Science of Design

  Bulletin of Japanese Society for the Science of Design 40 (1), 1-4, 1993

  Japanese Society for the Science of Design

Keywords

• Illusion
• Helmholtz Squares
• CRT

Details

• CRID: 1390282680389614848
• NII Article ID: 110008444852
• DOI: 10.11247/jssdj.40.1_1
• ISSN: 21865221
• ISSN: 09108173
• Text Lang: ja
• Data Source:
  • JaLC
  • CiNii Articles
• Abstract License Flag: Disallowed