• It's estimated that one-in-500 experiences more common forms of synaesthesia, like letter-colour synaesthesia, while one-in-25,000 live with rarer forms. (AAP)
Imagine knowing how the colour purple tastes, to see what music looks like or to know how certain numbers feel? People with synaesthesia experience this sensory cross-over every day. SBS explores the condition and asks: is synaesthesia is a hindrance or a gift?
By
Megan Blandford

9 Feb 2017 - 3:27 PM  UPDATED 9 Feb 2017 - 3:30 PM

Synaesthesia is a fascinating phenomenon in which any two of our senses cross over. Some people with this condition experience the condition by being able to taste sounds while others can hear colours.

So what’s it like to live with it?

Melanie Schoo tells SBS she experiences synaesthesia by feeling emotions when she sees letters and numbers.

“There are letters of the alphabet and numbers that are positive or happy, and there are numbers and letters that I perceive as being mean, nasty or negative,” Schoo explains.

“There is some colour association with days of the week as well, but it’s not as strong.”

“There are letters of the alphabet and numbers that are positive or happy, and there are numbers and letters that I perceive as being mean, nasty or negative."

Synaesthesia is genetic, and so this way of interpreting life is something that has always been with Schoo, who lives in Melbourne with her husband – whom she describes as “having a name that starts with the letter I enjoy the most”.

"I always thought it was normal, and then when I was about 10 there was a show on television about synaesthesia and I realised that’s what I have,” she says.

“I used to say things like, I’m sad because I’m eight and it’s not a happy number, but my parents didn’t delve any further into it.”

I named my anxiety Clive and it changed my life
Carolyn Tate decided to give her anxiety a name, and in the process stumbled upon a way to feel a whole lot better.

It took many years before Schoo sought a formal diagnosis of what she’d come to realise wasn’t a common perception of the world. “When I was in my 20s, I went through the process to get a formal diagnosis of high-functioning Asperger’s, which joined the dots,” she says.

According to Macquarie University researchers, the prevalence of the condition in Australia is varied. It's estimated that one-in-500 experiences more common forms of synaesthesia, like letter-colour synaesthesia, while one-in-25,000 live with rarer forms, like sound-odour synaesthesia.

In The UK, synaesthesia occurs in seven per cent of the population and it’s up to three times more likely to occur in people with autism spectrum order.

Synaesthesia doesn’t discriminate according to culture or race, although research is lacking: “If I had to speculate, I’d say it probably would occur in most cultures and races,” says The Australian National University Research School of Psychology's Dr Stephanie Goodhew.

“Culture wouldn’t be likely to shape the occurrence of synaesthesia, although it might shape the way it manifests.”

“The most common type of synaesthesia is where words or letters elicit colours, and the particular regions that process those stimuli are right next to each other in the brain.”

The way in which synaesthesia develops is intriguing.

“Early in your brain’s development, particular regions become more and more specialised in different functions. That process is imperfect in a synaesthete’s brain: the connections are maintained between particular areas which should have died out during those developmental stages,” says Goodhew.

“The most common type of synaesthesia is where words or letters elicit colours, and the particular regions that process those stimuli are right next to each other in the brain.”

A hindrance or a gift?

Some people with synaesthesia perceive it as a hindrance in their life, while others see it as a gift.

For Schoo, synaesthesia is simply part of her life experience. “I find it intriguing; it’s like a complex puzzle I’m always playing with,” she says. “It gives me a heightened appreciation for things other people might not have exposure to. And there’s never a negative reaction to it, because people are fascinated.”

She can see, though, that it could be difficult for others. “Some more invasive forms of it – like when you can taste colours – could be more challenging to deal with day-to-day.”

Having synaesthesia doesn’t often get in the way of Schoo’s life and work, although it does present a few challenges for someone who works in marketing, surrounded by words all day. “I’m proofing a page at the moment, and the letter ‘e’ (the most positive letter for me) is the first letter I see. When I look at any document; the ‘e’s are more prominent, and then the rest becomes visible,” says Schoo.

“I’m more conscious of it now and can manage it rather than be at the mercy of it – because it can impact on my mood or impressions of things.”

When someone with total blindness thinks they can see: Anton's syndrome
Mr B was diagnosed with total blindness. He was also totally unaware that he couldn't see and vividly described surroundings that did not exist. Brain imaging revealed strokes had damaged his visual cortex.
Move over sniffer dogs, human witnesses can also identify criminals by smell
“Nose-witness identification” is surprisingly accurate when used to identify criminals in a body odour lineup.