The Pulfrich Effect in Different Density Filters.
Previous research has found that when viewing an object in lateral motion with one eye, while looking through a filter, an impression of depth is conveyed. This effect is known as the Pulfrich effect. This experiment was designed to test the differences of this effect between higher and lower density filters. The subjects were asked to view a pendulum in motion and record what they observed. The results confirmed the Pulfrich effect, but nothing else.
The Pulfrich Effect in Different Density Filters.
There has been much investigation in the study of object perception. In regards to a single target-object moving horizontally to the observer's frontal plane, differences in perception have been found when a filter is placed before one eye. The Pulfrich effect describes a displacement in depth either toward or away from the observer when viewing the object in motion in this manner (Stevens, 1951).
This phenomenon is explained by the way the eye responds to light. The brain processes dimly illuminated stimuli slower than brightly illuminated ones, and is given mixed signals when viewing an object in motion with one eye covered by a filter and one eye uncovered. The image will therefore reach the brain a fraction of a second later in the filtered eye than in the unfiltered eye, and cause an illusion of elliptical movement (Lit, 1949).
This goal of this study was to observe the Pulfrich effect in different density filters as it applies to a swinging pendulum. Based on previous research it can be expected that an elliptical illusion of the swinging pendulum will occur.
Method.
Participants.
Three 22-year-old male student subjects (S) were selected for this experiment and performed it on each other.
Materials.
Pendulum. This can be made from a 12-18 inch string with a light weight attached to the bottom. This will be swung before S by the experimenter (E).
