Can you taste colours? How to tell if you have synesthesia

Does the number seven look red to you? Are letter “E”s green? You might have synesthesia. This phenomenon presents itself when two (or more, in rare cases) senses combine.

For synesthetes, the senses aren’t separate like they are for most people, so they may hear colours, or feel or taste them. For these people, piano music may be pink, sevens might be blue, or ice cream could be yellow – or triangular.

What is synesthesia?

The word, Greek in origin, means “to perceive together,”or “senses coming together.”Syn = together, Esthasia (aesthesis) = sensation.

Described by Sir Francis Galton (cousin of Charles Darwin), interest in synesthetes was first piqued in the science community in the 1880s. Synesthesia is “a neurological condition in which stimulation of one sensory pathway evokes sensations in another sensory modality,”according to a ScienceBlog post on neurophilosophy. It is involuntary, constant over time, and can vary considerably from person to person.

Despite being classified as a neurological condition, it does not generally affect daily functioning.

How many people have it?

The American Psychological Association says that about one in 2000 people have it, although some experts say that as many as one in 300 have some symptoms.

Another study suggests that somewhere between one in every 5000 to 100,000 people, a fairly broad guesstimate.

The problem with trying to find accurate statistics about this condition is that it’s not a medical problem, and so it’s not likely to be reported. People who have it either don’t realize they have it, or realize it’s unique, or they know about it, but don’t report it because there’s nothing to fix.

Who gets synesthesia?

Studies suggest that women are twice as likely as men to get it, and that it tends to run in families, suggesting a genetic component.

“Synesthetes tend to be more artistic, or drawn towards more creative and/or artistic professions and hobbies. They usually perform higher on cognitive assessment tests such as the WAIS-R, higher on memory tests such as the CVLT, but lower on tests of spatial function,”explains Dr. Veronica Gross of Boston University’s Synesthesia Project.

What causes synesthesia?

It’s still unclear. The APA says that 100 years ago, synesthesia was referred to as “crossed wires”in the brain.

Gross explains that some synesthesias “may be induced by the loss of a limb,”although the correct term for this phantom sensation is parathesias. In her work, she also explains that synesthesia is not drug-induced, despite similarities to the effects of some psychotropic drugs.

How do they test for it?

The team responsible for the standardized battery tests refers to a 1917 consistency test administered by Science which asked synesthetes to describe the colours associated with graphemes, and then asked the same questions five years later.

A 2001 article in APA.org explains that synesthetes were asked to associate a colour with each of 100 words. Their answers during an unannounced follow up test a year later were consistent with their initial test replies over 90 per cent of the time, while non-synesthetes were correct only 20 per cent of the time.

How is this different than using your imagination?

Synesthetes will have a consistent associations over and over, unlike a non-synesthete who may imagine a known picture when they smell a certain food cooking – an image of a pie when they smell a pie in the oven, to use Dr. Veronica Gross’ example in her Boston University Synesthesia Project. A synesthete will consistently imagine something unrelated – a colour for example – when they encounter the same smell, even if they weren’t paying attention to the smell.

What does science think?

According to synaesthesia.com, interest in synesthesia waned in the 1930s because it was thought that “internal feelings and thoughts are not measurable.”It wasn’t until a few decades later that researchers began to seriously consider the topic and started experimenting, looking for measurable results and data from studies.

How do I know if I have synesthesia?

You can take a test at synesthete.org. The test takes about 10 minutes to complete, says if you have synesthesia, and if so, which type.

Do people with synesthesia all have the same symptoms?

No. They can be divided into two basic groups: Projectors (or localizers) who “experience the colour with a spatial location” and associators (non-localizers) who don’t see colour in space.

The most common form of the phenomenon is grapheme-colour synesthesia, where people see colours and patterns when thinking about letters or numbers.

Another variation is colour-auditory synesthesia, or chromesthesia, meaning that voices or sounds are seen in the mind’s eye as colours or patterns, although a minority of people experience the phenomenon as visions projected outside the body.

People who have mirror-touch synesthesia have the sensation of feeling when they see someone else being touched, despite not being touched themselves.

Other forms of synesthesia include spatial-sequence, where numbers, days or months appear in a place or on a map, and motion-sound synesthesia, where respondents can “hear” a pattern of moving dots.

The synesthesia battery team is still adding tests for more variations of the phenomena, but taste-colour, smell-colour, and coloured orgasms are so far impossible to test.

There are many other combinations of the senses, but those are the most common. The degree to which people are affected varies considerably as well, with some people seeing colour in digits to others who see it in words, explains Gross, and colours can range from flat colours to complex patterns.

I have it - what do I do about it?

Enjoy the bragging rights. Gross writes that many syntesthetes find their synesthesia to be enjoyable and may even pity others who don’t share their way of seeing.