%0 Journal Article
%T A Thickness Illusion: Horizontal Is Perceived as Thicker than Vertical
%A Christian N. L. Olivers
%A Erik Van der Burg
%A Jasper M. De Waard
%J Vision | An Open Access Journal from MDPI
%D 2019
%R https://doi.org/10.3390/vision3010001
%X We report two psychophysical experiments that investigate a visual illusion that is considered common knowledge among type designers, but has never been studied scientifically. Specifically, the thickness of a horizontal line is overestimated in relation to that of a vertical line. Experiment 1 confirmed the existence of the illusion. In Experiment 2, we replicated the effect and showed that the illusion is closely related to the vertical-horizontal illusion, in which the length of a vertical line is overestimated in comparison to a horizontal one. Both the overestimation of thickness and length is larger when the stimulus is surrounded by a horizontally elongated frame, as opposed to a vertically elongated frame. We discuss potential explanations for the thickness illusion and its relation to the vertical-horizontal illusion. View Full-Tex
%U https://www.mdpi.com/2411-5150/3/1/1