Which processes in the brain are responsible for synesthesia, is so far disputed among researchers. Some scientists, for example, believe that synaesthetes are more closely related to different brain areas. Another group of researchers, including Kadosh, believes that different degrees of blockage within the brain are critical for synesthesia.
To test their assumption, the scientists hypnotized volunteers. The assumption behind this was that the blocking processes are loosened by the hypnosis. During the hypnosis, the scientists therefore suggested to the subjects a combination of colors and numbers. For some participants, they persisted with a posthypnotic command, even after the end of the actual hypnosis. These participants then showed similar symptoms as synesthetes: they could not correctly recognize a black printed one against a red background, since the number one had also been marked as red during hypnosis. Kadosh and his colleagues see this as proof that no special connections in the brain are needed for synesthesia.Roi Cohen Kadosh (University College London) et al .: Psychological Science, Vol. 19, No. 10. ddp / science.de? Markus Zen's ad