Are you able to see sounds, hear images, or color smells or words unconsciously? Do you see the months of the year, the days of the week, the numbers or letters in lists and colors that are always defined and ordered?
So you are part of the 1% of the population that has synesthesia, a phenomenon of the assimilation or interference of different stimuli such as smell, sight or taste in a single perceptual 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 to the scientific community. Until now, scientists wondered if these experiences were only congenital or, on the contrary, could be provoked. A study led by Sakari Kallio , from the University of Skövde (Sweden), has already found an answer.
Through hypnotic suggestion, people can experience perceptual changes .
In the research, the scientists subjected a group of eight people with normal vision , of which finally five remained, to the induction of synesthesia . The experiment had three conditions each with specific instructions for the volunteers to say 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-like color 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 from posthypnotic amnesia and did not recall being given any kind of instruction or hypnosis. Some did not experience these ‘loopholes’ , but others did not remember part of the induction.
“I felt a strong urge to name a color out loud, but then I saw that it was not the correct color. The strategy was to try to avoid naming the color that I thought was correct, and to try to say the color that I saw with my eyes,” he explained. one of the volunteers.
The subjects’ narratives described situations very similar to those experienced by real synaesthetics . Furthermore, the volunteers failed a “cheat” test in the same way that the synaesthetes failed.
The data does not lie
Ultimately, the results show that the perceptual changes observed in association with congenital synesthesia 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 hallucinations produced by induction are studied.
“Our study shows that hypnosis can induce synaesthetic 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 what cause these experiences. This brings us one step closer to understanding the causes of synesthesia and abnormal cross-interactions in the brain, “explains one of the co-authors of the project, Cohen Kadosh .
As the scientists explain, studying such experiences can increase understanding of perception and automaticity, as well as open up unique opportunities in cognitive neuroscience and consciousness research .
