Are you able to see sounds, hear images, or color odors or words unconsciously? Do you visualize the months of the year, the days of the week, the numbers or the letters in lists and colors always defined and ordered?
Then you are part of the 1% of the population that possesses synesthesia, a phenomenon of assimilation or the interference of different stimuli such as smell, sight or taste in a single perceptive act. Normally, it is defined as the attribution of a sensation to a sense that does not correspond to it.
The neurological condition of synesthesia has been a mystery for the scientific community. Scientists considered, until now, if these experiences were only congenital or, on the contrary, could be provoked. A study conducted by Sakari Kallio, from the University of Skövde (Sweden), has already found an answer.
Through hypnotic suggestion, people can experience perceptual changes.
In the investigation, the scientists subjected a group of eight people with normal vision, of which finally five were left, to the induction of synesthesia. The experiment had three conditions each with specific instructions for the volunteers to tell the true color of the symbols presented on a screen.
Three of the four most easily hypnotizable participants showed a strong association between symbol and color during a Stroop type naming test . A test that originally consists of analyzing the interference that occurs in the subject when he performs a test in which he must indicate the color of the ink with which a word is written that does not match its meaning.
At the end of the induction, the volunteers were interviewed to explain in detail what they remembered, if they were aware of what they had done and their subsequent experiences.
Some suffered posthypnotic amnesia and did not remember that they had been given any kind of instruction or hypnosis. Some did not suffer from these ‘gaps’, but others did not remember part of the induction.
“I felt a strong need to name a color aloud, but then I saw that it was not the right color, the strategy was to try to avoid naming the color that I thought was right, and try to say the color I saw with my eyes,” he explained. one of the volunteers.
The narratives of the subjects described situations very similar to those experienced by the real synesthetes. In addition, the volunteers failed a “trap” test in the same way that the synesthetes had failed.
The data does not deceive
In short, the results show that the perceptual changes observed in association with congenital synaesthesia can be rapidly induced by hypnosis. They also suggest that the subjective experience of each participant in the experiment should be carefully evaluated, especially when studying hallucinations produced by induction.
“Our study shows that hypnosis can induce synesthetic experiences in people, suggesting that additional connections in the brain are not necessary to experience cross-sensory interactions, changes in inhibitory processes (more interference between communication channels within the brain). They are the ones that cause these experiences, which takes us one step closer to understanding the causes of synesthesia and the abnormal cross-interactions of the brain, “explains one of the co-authors of the project, Cohen Kadosh.
According to the scientists, studying such experiences can increase the understanding of perception and automaticity, as well as opening unique opportunities in cognitive neuroscience and the investigation of consciousness.