Synesthesia, or its cousin ‘ideasthesia’, is a phenomenon in which individuals experience cross modal ‘qualia’ in response to certain triggers. In other words, perceiving letters or numbers might cause them to see colors or hear sounds, or hearing sounds might cause them to see colors.
It was previously believed that all forms of synesthesia were the result of specific developmental changes in the brain leading to stronger-than-normal connections between brain areas, or disinhibition of neurons causing nearby brain areas to fire in unison.
In a recent study though, it has been shown that it is possible for adults to actually learn to experience synesthesia through training. Here we will look at how this can occur and at what it might mean…
How We Can Learn Synesthesia
In the study, it was shown that training could result in individuals developing grapheme -> color synesthesia. In other words, they could learn to associate letters and numbers so strongly with colors that they would then ‘experience’ those colors when presented with the corresponding graphemes.
This training specifically involved exposure to colored letters along with recall tasks where the subjects had to remember the assigned color for each of the letters. Training consisted of 30 minute sessions, five days a week for a total of nine weeks. Participants also had ‘homework’ which involved reading e-books where the letters had been colored.
So how does this work? Essentially it’s a simple case of classical conditioning which causes changes in the brain through brain plasticity. Brain plasticity is the term used to describe the adaptability of the brain – its ability to change shape in response to training and for specific regions to get larger or smaller depending on the way that we use them. For instance, a cellist is more likely to have larger areas in the brain corresponding to sensitivity and dexterity in the finger tips as a result of their musical training.
One of the ways that brain training could lead to synesthesia-like effects would be through long-term-potentiation – the strengthening of neural connections due to repeated use. The expression often used to describe how this occurs is:
‘Neurons that fire together, wire together’
In other words, if you see a letter and a color together often enough, then this can eventually lead to a physical link between those two things which in turn means that seeing one would trigger the ‘sensation’ or ‘experience’ of the other.
Whether or not this is the same synesthesia as the congenital condition that we normally associate with the term is unsure but suffice to say that it is certainly an interesting demonstration of the powerful adaptability of the brain. It also makes you wonder what other potential uses there might be for this type of training.
‘Number form’ synesthesia is a type of synesthesia wherein the synesthete actually ‘sees’ a grid of numbers when they attempt a math sum and which then helps them to perform the sum more accurately. Could we train such an ability in order to enjoy almost superhuman math skill?