We are two students of psychology at the University of Aarhus, that have a general interest in subliminal perception. Since the litterature tells different stories concerning the usage and effectiveness of this phenomenon, we decided to test it ourselves.
We created two experiments that aimed at testing two of the myths on the area. The results of these experiments were presented at the 27th International Congress of Psychology (ICP-2000) in Stockholm on the 27th of July 2000.
Below there is a general introduction to the two experiments and links to more detailed information.
Experiment1: Subliminal Manipulation
The idea of this experiment was to test the well-known myth created by James Vicary in 1957, when he claimed he had increased the sale of Coca-cola and popcorn in a cinema by flashing the messages "Drink Coke" and "Eat popcorn" onto the screen while the audience was watching a film. Vicary later admitted that the study was a fabrication (Pratkanis & Aronson, 1992). Nevertheless since then there has been a wide belief in the "magic" and hypnotic nature of subliminal perception.
To test the myth we created a test-situation where the subjects had to rate 10 different "brands" (10 different symbols) after being subliminally influenced by one of them. If the subliminal exposure has the influence claimed by Vicary, the "brand" (symbol) that was flashed in should be chosen (rated higher) more often by the subjects in the experimental condition than by the subject in the control condition.
Experiment 2: Gender Specific Influence
Another well-known feature of subliminal perception is Wilson Bryan Keys claims that we all are constantly influenced by embedded sexual symbols in TV, commercials and government materials. Although we don't consciously perceive these sexual symbols they influence our behaviour and thoughts significantly (Key 1989). The substantial evidence that Key puts forth has been widely criticized (e.g. Vokey & Read, 1985).
To test these claims we created a test-situation where subjects had to rate a picture. In the experimental condition we subliminally presented a sexual symbol (a picture of an erected penis) while subjects were watching the picture. If Key is right this should increase the rating of the picture compared to controls.
Key, W.B, (1989): "The age of manipulation"Madison Books, Lanham, Maryland
Pratkanis, A. & Aronson, E. (1992): "Age of Propaganda" N.Y.: W.H. Freeman and Company
Vokey & Read (1985) "Subliminal messages - Between the Devil and the Media". American Psychologist 40