Post hypnotic suggestion automatically changes the conscious color perception

Authors: Sakari Kallio and Mika Koivisto, University of Skövde, Sweden en University of Turku, Finland

The altered perception by hypnosis is a puzzle still to be solved. The Scandinavian researchers Sakari Kallio and Mika Koivisto wondered if it would be possible to change the observation of colors making use of post hypnotic suggestions. They showed a grey object to test persons that was covered after different time intervals.

After covering the target, the test persons very quickly mentioned another color. This altered observation was not observed with the control-group nor with the test persons without hypnosis. By giving them the suggestion for amnesia the test persons did not know what suggestions were given during the hypnosis.

More importantly is that the test person could not change the perception of color without the hypnotic suggestion. The researchers concluded that hypnosis can change the observation even with a very automatic process such as looking observing colors.