Experiments on the Distance-Perception between Two Stimuli. I

Abstract

When two stimilar stimulus figures (lines or points) are presented simultaneously on a horizontal plane with a certain distance from each other, we perceive the distance sometimes greater and someties smaller phenomenally in according with the sonditions of presentation. The aim of this experiment was to examine these phenomena in relation to (1) intesity of stimuli (ratio of rad. lux), (2) size of stimulus figures, (3) objective distance between two stimuli.
The finding were as follows :
1. The stronger the intensity of stimuli becomes, the greater becomes the phenomenal distance, and the amount of over-estimation becomes less with the increase in the objective distance.
2. The longer the length of the lines (stimuli) becomes, the greater becomes the phenomenal distance. The amount of over-estimation becomes larger with the increase in the objective distance, but the proportion of over-estimation is the greatest at a certain distance, and then it becomes smaller as the objective distance increases further.
The result seems to be affected also by other factors such as observer's attitude or inspection time, etc., so it is necessery to analyse these factors next time.