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Synaesthesia and savant syndrome: are we all superhuman?

by Katy Edgington,Science Relief Contributor
Jason Padgett brain scan

Professor Berit Brogaard and Kristian Marlow from the St Louis Synesthesia Lab share their expertise on this fascinating condition and how it informs our perception of perception…

Richard Feynman, Vladimir Nabokov, David Hockney. What do these famous figures have in common? They are all synaesthetes. Feynman and Nabokov linked letters and numbers to colours, while Hockney perceives music in terms of colour and shape. Synaesthesia is a condition in which stimulation of one sensory or cognitive stream somehow interacts with another sensory or cognitive stream in a way that it normally would not.

While most cases of synaesthesia are developmental and hereditary, it can be acquired later in life as a result of, for example, traumatic brain injury. Far from being disabling or disadvantageous, many people with synaesthesia have reported that these phenomena simply form a part of everyday life or even confer unexpected benefits.

Research on all forms of synaesthesia is carried out at the St Louis Synesthesia Lab, which is affiliated with the University of Missouri-St Louis (UMSL) and has collaborating partners in Denmark, Canada, Finland and the United Kingdom. Director Berit Brogaard, Professor of Philosophy and Psychology, and Associate Director Kristian Marlow, a graduate student in Philosophy at UMSL, started by explaining some of the ways in which synaesthesia can manifest itself.

"There are numerous different kinds of synaesthesia," Professor Brogaard began. "One of the most common forms is grapheme-colour synaesthesia, which is where letters or numbers give rise to specific colours. There are people who have so-called mirror-touch synaesthesia who experience the feeling of being touched when they see other people being touched. There are others who see colours when they taste something and some people even see colours when they feel fear."

One of the first cases studied at the St Louis Synesthesia Lab was that of Jason Padgett. He was working as a salesperson in a furniture store in 2002 when he was beaten up and suffered injuries to the head. He fell unconscious and his muggers continued to beat him.

"After the attack, Jason was able to see things in terms of mathematics," said Professor Brogaard. "Looking at moving or static objects, he would see complex geometrical shapes and figures with fragmented boundaries. He started drawing some of the things he was seeing and since then he’s won several prizes for his artwork.

"Jason had never been to college, so he took some courses in mathematics at his local community college in order to be able to talk about his synaesthesia and so-called ‘savant syndrome’. We did some brain scans and found out that he uses a specific part of the left hemisphere of the brain which is not even in the visual area. It’s a part of the brain responsible for planning actions and mathematical calculations."

When you ask someone to generate an image in their head of something which does not exist – for example, to imagine what an object composed of a cup and a mobile phone would look like – a specific area of the brain is involved. It is this area which is very active in Jason. Surprisingly, scans have shown that Jason does not have any activity in response to stimulation of his synaesthesia in the usual areas of the brain.

Marlow described another incidence of acquired synaesthesia that the team has looked at in detail. About seven years ago, when Derek Amato was in his thirties, he dived into the shallow end of a swimming pool and hit the front of his head. Without a background in music or any musical training whatsoever, Derek woke up a few days later with an intense urge to play music. He went to a piano and started playing classical music as if he was a professional.

"It transpired that Derek has a type of synaesthesia where he sees tiny blocks almost like the equaliser on a stereo," Marlow explained. "He has no idea why, but his fingers automatically follow the blocks and he is able to play beautiful music. He finds that he is constantly composing new material; even as he is speaking to people he’s scoring music with these little blocks. That has led him to start a career writing soundtracks, whereas before he worked as a salesperson."

The researchers have also done a lot of work with Lidell Simpson. Lidell was born with cortical deafness, so he was profoundly deaf but with no apparent damage to the anatomy of his ears. He was unable to hear until he reached the age of five and received electronic hearing aids.

"Lidell has always heard sounds which correspond to motion," said Marlow. "For example, he describes hearing a ‘plink’ when a light is turned on and a ‘plunk’ when it is turned off. He also hears a ‘ping’ when he comes across a face he is acquainted with; so he would hear a certain type of ‘ping’ if he saw my face and another type of ‘ping’ if he saw his mother. What’s interesting about this is that if Lidell goes into a crowded room with only one or two people he knows, he will hear their ‘ping’ before he recognises their face."

This is the result of a condition called face blindness, which means that Lidell has trouble recognising faces visually; the way he recognises people is through sounds. He has an ‘extrasensory’ ability to recognise people when it should not be possible.

There are currently a few ideas in circulation about the neural systems and processes which cause synaesthesia. One hypothesis suggests that we are all born as synaesthetes but that as our brains develop we acquire mechanisms which block the types of feedback associated with synaesthesia.

"According to this theory, you might also see a colour when you see a shape as a baby, but as your brain matures the feedback to the colour area would be blocked," explained Professor Brogaard. "Synaesthetes would supposedly maintain some of the connections – between taste and colour, for example – which other people have unwittingly blocked out."

Another theory being explored is that synaesthesia is memory-based. The results of some experiments seem to suggest that memory is involved at an unconscious level in these synaesthetic connections, as Professor Brogaard elucidated.

"This doesn’t mean that people who have grapheme-colour synaesthesia had little letters that were these colours when they were young, it just means that when they were growing up and learning letters and numbers they could have been unconsciously associating them with certain colours to make it easier. That’s not to say it is a conscious strategy, more an unconscious strategy that has become automatic over time to the extent that – in those we call synaesthetes – it can’t be turned off."

Another possibility under consideration is that synaesthesia is, in many cases, the gateway to unconscious processes in the brain that people who are not synaesthetes (or savants) do not have access to. There are regions of the brain – such as the posterior parietal cortex, which is responsible for the complex calculations necessary to produce planned movements – that are in constant use but which we do not have conscious control over. Synaesthetes and savants could gain access to some of these unconscious processes, or so the theory goes.

According to Marlow, both synaesthetes and non-synaesthetes are increasingly acknowledging that people do not see the world in the same way, and many more people are recognising that they are synaesthetes. Although most synaesthetes understand that the colours or things they are seeing are not visible to everyone else, there is usually a moment when they realise that their parents and other people are not experiencing the world as they are.

"There was one girl who told her father that it was cool when she was learning to write ‘R’ that the colour of ‘P’ would change just by adding that diagonal line," remarked Marlow.

"A lot of people keep their experiences secret all their life for fear of being ridiculed. In Lidell’s case, as a child struggling to deal with being deaf, it was almost too much for his parents to find out that he had synaesthesia, which at the time wasn’t much accepted as a real condition. They simply didn’t have the tests that we have now to show that it is very real."

With the airing of several television documentaries, both in the United States and the United Kingdom, as well as the appearance of books by and about synaesthetes and savants, there is a growing acceptance that different modes of perception do exist. Indeed, they may exist within all of us.

"Evidence from people with acquired savant syndrome and acquired synaesthesia indicates that we all have the capacity for creative talents and synaesthetic experiences," stated Professor Brogaard.

She went on to explain that a number of philosophical hypotheses about perception are challenged by the inroads made in synaesthesia research and related fields.

"The modularity hypothesis posits that each part of the brain has a very specific function," Professor Brogaard pointed out. "This is challenged by observations of people having visual experiences, for example, when the visual cortex is not active."

There is also the idea of a distinction between low-level and high-level perception. This idea is challenged too, because we have theories and evidence to suggest that there is more feedback in the brain than previously thought.

"An example of low-level perception would be the perception of colours and simple shapes, whereas high-level perception would be the recognition of faces or understanding language," she went on. "It’s not as simple as saying that the visual cortex is responsible for colours and shapes while the auditory cortex is responsible for aspects of sound and so on. We can’t draw a definitive line between low-level and high-level perception."

Another instance is the supposed opposition between conscious experiences versus unconscious processes, as Professor Brogaard outlined. 

"We have seen lots of cases of perception at the unconscious level, so we can answer in the affirmative the old philosophical question ‘could that be perception at an unconscious level?’ There are lots of perceptual processes that are unconscious."

I asked Professor Brogaard and Marlow to expand on some of the key themes and aspects of the work being pursued at the Lab. Currently researchers are working with a psychopharmacologist on the possible connection between synaesthesia and psilocybin, which is the active compound in magic mushrooms.

"People who have taken psilocybin have described experiences similar to those described by synaesthetes, and the question has been raised whether the same processes are being activated in the brain by this drug," explained Marlow.

"Presumably psilocybin can bring out creative abilities, and perhaps transcranial magnetic stimulation (TMS) can too," Professor Brogaard continued. "Other things like a hard knock to the head – from being beaten up or hitting it on the bottom of a swimming pool – can bring them out. But sometimes really hard work can also enhance these abilities."

This is exemplified by the case of Danial Kish, who was blind from the age of 18 months. He uses echo-location, as do bats, certain whales and dolphins, in order to navigate and has been the subject of research at UMSL.

"Both of Danial’s retinas were removed so there was no way that he could see, but he started to navigate based on sounds in the environment," Marlow explained.

"By clicking his tongue he is able to create a signal which means he can map out a room spacially. This doesn’t just allow him to locate walls; he is able to pick up coffee cups and find other small objects. He also goes mountain-biking in the wilderness and camps by himself. If you see Danial in person it’s almost impossible to tell that he’s blind. What’s especially interesting is that he has also taught more than 500 people to do this."

Examples like the one Danial has set are leading some synaesthesia experts towards the idea that genius and special abilities are hidden aspects of all of us, and that they can be triggered by certain events or stimuli. Some researchers have attempted to induce experiences of this sort and enhance natural abilities, most notably Professor Allan Snyder. Professor Snyder uses TMS, a non-invasive method of brain stimulation, to encourage ‘normal’ people to temporarily improve their artistic and numerical skills.

In the future, Brogaard and Marlow suggest, our everyday experiences could be enhanced in various ways as a result of research like this aimed at augmenting our intellectual and creative abilities.

Visit the St Louis Synesthesia Lab website to find out more. You can complete a survey to find out if you are eligible to take part in their research

Like this Facebook page for updates on Berit and Kristian’s forthcoming book, The Superhuman Mind: True Tales of Extraordinary Mental Ability 

Follow Science Relief on Twitter @ScienceRelief . We're also on Facebook & Google+.

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