Synaesthesia – the neural pathway to exceptional memory?

Synaesthesia – the neural pathway to exceptional memory?

You have heard of the phrase – see the world in colour. What if your perception of touch, smell, sound, numbers, and letters was also in colour?

Synaesthesia is a neurological phenomenon and is defined as a condition in which someone experiences things through their senses in an unusual way, for example by experiencing colour as a sound, or a number as a position in space. For example, a person may associate the number four with the colour blue.

‘If someone scratches a blackboard with his or her nails, I taste iron. The intro of “Time” by Pink Floyd is golden yellow and blue. Poems have colour if they are cited, and sometimes when I read them’.  A quote from an unnamed participant in a case study and research carried out by Romke Rouw, H. Steven Scholte and Olympia Colizoli at the Department of Psychology, University of Amsterdam, The Netherlands.

Synaesthesia is not a disorder. It runs in families and hence, seems to have a genetic basis. People with synaesthesia experience the world in remarkable ways and decades of research has found evidence to suggest that people with the condition, known as synesthetes, have enhanced memory function and memory recall.

There is extensive research and evidence to prove that those with synaesthesia do possess exceptional memory function and long-term recall. Furthermore, recent breakthroughs also suggest that anyone can teach themselves synaesthesia! 

Humans remember colours much better than we remember a lot of other things so by simply forming a new habit of associating numbers with colours, we can improve memory performance. 

Before we begin flexing our neurological muscles, let’s delve into some of the more common forms of synaesthesia.

Types of Synaesthesia

Generally, about five per cent of the population are affected by one or several forms of synaesthesia. 

1: Grapheme–colour synaesthesia or colour–graphemic synesthesia

This is one of the more common forms of synaesthesia where letters or numbers are seen as colours. These synesthetes also show better memory for words.

2: Spatial-sequence synaesthesia.

In this type of synaesthesia numbers, months of the year, or days of the week form precise locations in space or even may appear as a three-dimensional map.  Some people see time like a clock above and around them.

3: Chromesthesia

Chromesthesia is the association of sounds with colours. For example, sounds such as doors opening or groups of people talking will elicit an association with colours. For others, colours are triggered when music is being played.

4: Number Form

Number Form synaesthesia is like a mental visualisation of numbers that automatically and involuntarily appear whenever that person thinks of numbers. These numbers might appear in different locations and is different from person to person.

5: Mirror Touch

Mirror Touch synaesthesia is where individuals feel the same sensation that another person feels, quite literally. If a person with synaesthesia were to witness another person being tapped on the back, for example, they would experience the sensation as if it was them that was being touched. A study published in Nature Neuroscience by Michael Banissy and Jamie Ward shows that mirror-touch synaesthesia is also linked with empathy.

A sixth sense

Most humans have five senses with which to explore the world. Sight, sound, smell, touch, and taste. Synaesthesia is a blending of the senses. Often referred to as a sixth sense, years of global research into synaesthesia has unearthed evidence, theories, and hypothesis about the correlation of synaesthesia with memory, long term recall and enhanced IQ.

Imagine for a moment you hear a familiar song, word, or phrase. Often, they will invoke memories and remind us of someone or something. Sometimes these memories stretch far back to an earlier part of our lives, our younger years, a forgotten memory. Despite the length of time passed, our brains still form an association and a connection due to a sensory trigger.

But what if this recall and memory function was heightened due to a sensory superpower?

Image of PI

Life of reciting PI

Daniel Tammet, a synesthete, can visualise numbers up to 10,000 with a distinct colour, shape, and texture. His synaesthesia has enabled him to recite pi to over 22,500 places! When multiplying numbers, Tammet says, “I see two shapes. The image starts to change and evolve, and a third shape emerges. That’s the answer. … It’s like maths without having to think.” Daniel has also learned 11 languages, some he mastered in only a week.

Synaesthesia gives a whole new meaning to the concept of perception and higher cognitive functions such as memory. The amalgamation of a more complex brain connectivity, a blending of the senses and more neurons firing together may be responsible for enhanced memory in synesthetes.

In Synaesthesia: Does it have an effect on memory, by Elizabeth Evans, she discusses how synesthetes have enhanced sensory processing compared to those who do not have the same perceptual experiences. Furthermore, “in addition to facilitating processes in individual sensory modalities, synesthetes also show increased communication between the senses unrelated to their synesthetic experiences, suggesting that benefits from synaesthesia generalize to other modalities as well” (Brang & Ramachandran, Survival of the synesthesia gene: Why do people hear colours and taste words. PLoS Biology, 2011).

Increased sensory processing and memory abilities are common attributes with synaesthesia. A study carried out at The University of Rochester in 2016 supported “the hypothesis that synesthetes have a superior ability to learn and retain shape colour associations” (Bankieris & Aslin, Explicit associative learning and memory in synesthetes and nonsynesthetes. i-Perception 2016,)

Is it possible to learn this memory superpower?

Many researchers suggest that there is a link between synaesthesia and memory, but more research is required to examine if the improved memory abilities of certain synesthetes could possibly be teachable to other synesthetes, or even people without the condition.

However, some of the research to date opens the door to the possibility that synaesthesia can be taught.

But how?

Image of coloured numbers

1: Read in colour

A group of psychologists at the University of Amsterdam have been testing whether synaesthesia might be learned. The findings are inconclusive but intriguing, nonetheless. In their research, they focused on the most common type of the condition - colour-graphemic synaesthesia.

A group of 17 non-synesthetes were given certain books to read all of which were purposefully selected and contained common letters printed in colour. The researchers' findings suggest that, because of this coloured-letter exposure, the participants had built up a colour-letter association that existed independently of the letters themselves suggesting that reading in colour could be a promising avenue for training grapheme-colour synaesthesia.

A breakthrough for enhanced memory? Perhaps.

2: Association

In an article from the Huffington Post called “Yes, You Can Teach Yourself Synesthesia (And Here’s Why You Should)” by Carolyn Gregorie, she explains how someone can teach themselves to be synesthetic. She suggests that in order to do this you have to start associating two things like colours and letters in a single category. She also encourages people to practice associating two things that don’t normally go together because they will be able to retain and retrieve memories better- for example a sound and a colour like the sound of a doorbell with the colour yellow.

Train ourselves to think in colour? Seems straightforward.

3: Brain training

Duncan Carmichael, from the University of Sussex, believes we are all potentially born as a synesthete.

Researchers from the University found that daily brain training can help people experience colour when reading words or letters. A group led by Daniel Bor wanted to find out what more intensive training could do. As well as using specially coloured e-books, they gave people daily half-hour training sessions to teach them 13 letter-colour associations, using progressively harder tasks.

Brain training could be in the form of quizzes or games, memory recall or puzzles. Many in their research also began to associate emotions with certain letters. Some reported that the letter X felt boring, while W felt calm.

Further research carried out by Olympia Colizoli and her colleagues in Amsterdam also states that to become synesthetic you may be able to trick your brain with brain training for 30 minutes a day.

Olympia and her colleagues tried to mimic grapheme-colour synaesthesia by having people read books in which only some of the letters were always coloured in with particular colours. After 9 weeks of testing and implementation, the volunteers all showed strong similarities with natural-born synaesthetes. The volunteers also registered a dramatic increase in IQ.

Testing your recall of colours associated with up to 13 letters of the alphabet has proven to be a successful tool amongst many researchers including Olympia and the team at the University of Sussex.

4: Sharpening our sense of hearing

Training ourselves “into” synaesthesia is not only possible with colours and letters. You may recall earlier in this article we mentioned Chromesthesia, the association of sounds with colours. The first step towards growing self-awareness of synesthetic experiences is to be more attentive to our sense of hearing. Meditation and practising mindfulness are great ways to begin.

Before you know it, you will be hearing colours.

5: Use colours to describe sounds

Simple, but effective. Practice describing songs using a colour - a pop song might be yellow whereas a blues ballad might be….well blue!

Image of colours

The power of colour

Can colour result in improved memory abilities?

Colour is believed to be one of the most important human visual experiences and a major part of our early cognitive development. Colours can produce a higher level of attention, improves learning and is effective in increasing memory performance so who is to say that we can’t teach ourselves new habits and ways of learning that include colour association.

Who is to say that we can’t teach ourselves to have synaesthesia, or at least one form of it. 

Only time and further research will tell.


Of course, with any research, particularly in the field of neuroscience there is much work to be done. There is a lot we do not know about the brain, and as a consequence, many would argue that you cannot teach synaesthesia.

Amongst the growing research been carried out in the area there are several theories that suggest that if synaesthetic experiences do not directly enhance the memory, then the alternative is that this very enhanced memory itself is part of a neurocognitive disposition

which may bring about certain forms of synaesthesia rather than the other way round.

Research on memory in synaesthesia is still in its infancy but certainly what has been discovered so far is exciting and worth exploring further.

If you’d like to explore the topic of synaesthesia yourself there are many great books written on the topic:

The Man Who Tasted Shapes (1993) by Richard Cytowic

The Tale of the Dueling Neurosurgeons (2014) by Sam Kean

Blue Cats and Chartreuse Kittens (2001) by Patricia Lynn Duffy

Blog by Genie O Dowd

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