Synaesthesia is a fascinating condition that can be simply described as an intertwining of senses. This means that where information that is meant to stimulate one of our senses instead stimulates several of them.
The triggering experience would be called the inducer and the triggered experience, the concurrent. As an example, a synaesthete, a person who has synaesthesia, may describe their experience of seeing colours when reading letter. In this case, the inducer would be the letters and the concurrent would be the colours. These are automatic sensations that they have no control over. This means that it is not something that they can simply turn off and then back on again.
Types
Synaesthesia is something that is linked to our 5 senses, smell, touch, sight, taste and hearing. But, it is not as simple as creating a link with each of these senses as there are countless sub-categories that make up our 5 senses. This means that there are a vast number of different types of synaesthesia. Some of these can include:
- Grapheme-colour = Experience colours when they read words, see letters, think about letters, hear them or hear sounds. For example, A=red, B=blue, C=yellow
- Spatial sequence = This is where sequences such as letters, numbers, months and dates occupy points in the space around them
- Chromaesthesia = Association of sounds with colours
- Mirror-touch = Someone who experiences touch by looking at someone else being touched
- Tickertape = Automatic visualisation of written words that can be seen as in the form of subtitles
- Hearing-motion = Vision such as motions or colours can evoke the sense of a smell, taste or sound
- Lexical-gustatory = This is where words can evoke different tastes
- Auditory-Tactile = This is where sounds produce a tactile sensation on specific parts of the body
- Number form = This occurs when a mental map of numbers appears whenever a person thinks of a number
- Ordinal linguistic personification = This is where inanimate concepts or objects are given human characteristics and qualities such as genders, personality traits and feelings. This can also apply to sequences that are in order such as days and months.
It is also quite common for a person to have more than one type of synaesthesia. This is something that is more likely to occur in clusters of the same sense rather than two different senses.
Causes
There is a genetic component to its development as it has been found to be more common in first degree relatives.
At one point it was believed that females were more likely to develop synaesthesia than males, however, more recent studies have shown that there is an equal chance that either sex could develop it.
It is also thought that early childhood experiences and learning could influence its development. As an example, growing up children are given various toys or learning aids to help them such as number sets or alphabet sets. The specific letter-colour pairing of these can later be found in adult grapheme-colour synaesthetes.
Testing
There are some difficulties with testing for synaesthesia as some people who have it may not be aware of it. To them what they are experiencing is something that they have always had, they do not know any other way of living. For this reason, they may also believe that everyone else lives their life the way they do, see the world they do and experience it in the same way. This explanation of it as being something that is completely normal is why the thought of being tested would not even cross their mind. In addition, there are some cases where it could be due to the fact that they only have a very mild form of the condition so they do not recognise any problem with what they are experiencing.
There is no specific test that can be used to diagnose someone. But, there are researchers who can use both computer programs and questionnaires to measure the association of experiences, senses and activation of certain parts of the brain.
Living with
Synaesthesia is not what would be considered a noticeable condition which means that you could meet someone with it during your life and not even realise it.
Some people may not like the term condition being used as it implies that there is a need for a cure. It is also not a mental health condition as it is generally described as a positive experience. It is something that provides them with a unique perceptual experience. This is why some people may see this as a gift and cannot imagine their lives without it.
There has also been research carried out into its link with memory. This is due to their perception of specific words, letters or sounds with certain colours, sounds or images. This means that they may hear or read a sentence and remember the associated sense they have. This could also explain pick up some things quicker than other such as learning a language.
However, for some they may report having what is called sensory overload. This is where they become exhausted and overwhelmed by the amount of stimulation they are experiencing. This can make them decide to avoid certain situations and going to particular places.
