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Sound cognition and perception - Synesthesia

Sound cognition and perception

Synesthesia

    Jamie Soar

The term Synesthesia, derived from the Greek words ‘Syn’, literally translated as together, and ‘aesthesia’, as sensation, is a term used to define a group of neurological, perceptual phenomena associated with sensory modality, where stimulation in one sensory modality gives rise to an experience in another. This could range from experiencing a taste in ones mouth when reading or hearing a certain word, to associating a colour or shape to a piece of music. Although the latter example deviates slightly from the definition, as the colour is ‘felt’ rather than physically seen, it is still grouped within the different variants of synesthesia.

  The most common type of synesthesia is ‘Chromatic-Graphemic Synesthesia’, or Colour-Letters, or even numbers, where the person with synesthesia, or synesthete, ‘sees’ a colour when reading a certain letter, number or word, or sometimes a composite of colours. For example, when reading the letter ‘A’, the synesthete may see it as being a ‘Red’ letter, or even as descriptive as seeing ‘7’ as ‘the colour of autumn leaves in mid-October’.

  This is only one example of synesthesia, as there are many more types of sensory reactions a synesthete may experience, sometimes experiencing more than one type. either separately or simultaneously.

As a result of the diversity of synesthesia, the reasons behind people developing synesthesia are still relatively unknown, identifying someone as a synesthete presents some challenges. There have been reports of patients suffering from medical conditions such as eye disease, brain damage, and migraines experiencing very similar qualities that indicate some form of synesthesia, and there have also been similar effects reported with regard to individuals using hallucinogenic drugs such as Lysergic acid diethylamide (LSD) and mescaline, however there is a large portion of people who are physically healthy who have synesthesia, present from early childhood,  which is commonly referred to as ‘Developmental Synesthesia’.

 This is compelling evidence which suggests that synesthesia does not come about as a result of a medical condition. Instead, some theories suggest that everybody develops some form of synesthesia in the first few months of life. As the brain processes brand new information, it makes certain associations to certain objects, sounds and events with their surroundings. For instance, when at a young age you are presented with a picture book, and there is the word ‘train’ printed in blue, or there is a blue train on the page, your brain may start to make these correlations. It is then thought that a large percentage of us lose these associations as our brains mature, however, a small percentage retains the brain pathways that made these associations and as a result develop synesthesia.

  There are theories, however, that do not support this thinking, rather, they consider Synesthesia as a brain dysfunction, where cross-wiring has taken place during development of the sensory region of our brains, and describes Synesthesia as a ‘breakdown of modality’. These theories are concerned with finding where the link is in the brain as to what is different in synesthetes at the psychological level, while remaining agnostic to the possibility that cross wiring of sensory signals happens anyway.

  Due to its nature and diversity, there is no standard test to determine whether someone has synesthesia or not. It is, after all, a private, subjective experience that cannot be shared with an independent observer.

  That said, it is possible to obtain indirect, objective measurements of synesthesia from a subjects performance when identifying certain stimuli under specific conditions. For example, synesthetes may be slower to judge the colour of a green square if preceded by a letter they experience as red than by another letter experienced as green (e.g., Muttingley et al., 2001)

  A number of criteria are also expected. Firstly, the report must be consistent over a period of time. Months or even years later when the test is repeated, the synesthete must show identical results, reporting the same colour-letter correlation. Furthermore, the possibility of these effects being induced by a delusional state or drug use must be ruled out, nor simply metaphorical speech, and that these effects must be present from childhood, involuntary and vividly experienced, although not necessarily projected externally. (Smilek & Dixon, 2002)

  It is common for synesthetes to feel that their experiences are perfectly normal, and that not having synesthesia to them is akin to someone without it trying to understand what the experience would be like. This brings up several problems with regard to explaining it to those unfamiliar with its effects, such as close friends or family. This is especially an issue for those of a young age, where people are quick to judge and the result could involve being subject to disbelief, ridicule or even scorn, and therefore forced to hide their synesthesia. To a non synesthete, this would almost feel like having perfect eyesight, and then being forced to deny the existence of colour, as if one was colour-blind. To a synesthete, the different sensory reactions they experience are part of their day to day life, and are how they perceive the world. To us, taking the letter ‘o’ and changing it into a triangle, it is no longer an ‘o’, it is simply a triangle. To a synesthete who sees ‘o’ as white, if the ‘o’ were to no longer be white, to them, it is no longer an ‘o’. (e.g., Pat Duffy, 2002) It is important, therefore, not to make the assumption that we all perceive the world in the same way, instead understanding the idea that no two people think, feel and perceive the same way. “The world should not be mistaken for a copy of the world as described by physics or biology.” (Merleau-Ponty, 1962)

  There are many forms of synesthesia that have been identified, ranging from the aforementioned chromatic-graphemic variant, the ability to see coloured letters or numbers, where each individual grapheme has it’s own colour, and occasionally more than one colour but also types such as chromatic-tonal synesthesia, where someone can experience each of the notes in music as a certain colour, and can be as broad as a song having a certain colour or aura, to being able to identify each note as it’s own individual colour.

  However, synesthesia is not only about colour. There are certain types of synesthesia where certain words or names that can invoke tastes or smells in the synesthete. The sensations experienced could be related in some way to how the words sound, April tasting of Apricots, Barbara tasting of Rhubarb. (James Wannerton, 2002)

  With this in mind, one issue of synesthesia is that these sensory responses are entirely involuntary, and sometimes the experiences can be unsettling, or even in some extreme cases completely repulsive. For instance, the sound of an instrument in an orchestra, such as a clarinet may be pleasant to a synesthete, but the colour seen due to the tonality of the instrument may be an unpleasant colour, or a particular word may induce an unpleasant taste such as earwax or a food the synesthete does not like.

  As well as having some drawbacks, people with chromatic-graphemic synesthesia or chromatic-tonal synesthesia may have certain advantages over regular non synesthetes. Colour is used extensively in the process of organization, with colour coding being the most common, and acts as a cue for remembering the order and placement of objects such as books or documents. People with chromatic-graphemic synesthesia, or colour letter synesthesia, could use their unique perception to help them perform better in certain tasks involving letters or numbers. For instance, someone who has a certain colour for every letter in the alphabet could have an advantage in spelling, as there is a possibility that as well as vocalizing the sound of the word to look for clues, they could also recall the different ‘colours’ of the word, and spell it out using this information. The suggestion that chromatic-graphemic synesthesia can be used to aid the forming of words motivated a synesthete to replace all the keys on his laptop computer. Rather than his keyboard displaying all the graphemes, the new keys displayed only the colours which corresponded with each grapheme. After this, it was found that the synesthete in question was able to type several times faster than before.

  It is important to remember, that while in some instances they are related, synesthetic colours and real world colours are entirely separate and for the majority are experienced internally. Consider the Stroop test, where colour names interfere with the speed an accuracy of naming the colour of the ink in which the words are written, for example, it takes longer to respond with ‘red’ when the word ‘Blue’ is written in red ink than it does with the word ‘Boat’ when it is written in the same coloured ink. When a variation of this test is carried out on a synesthete, similar effects are present, when words which appear to a synesthete as one colour are written in a different coloured ink. For instance, a synesthete may perceive the word ‘Bank’ as a yellow word in relation to their synesthesia, however when printed in another colour, the synesthete has slower speed and accuracy when trying to name the colour of the printed ink, and may stumble. Similarly, this could be applied to people with colour-music synesthesia. In an independent study, a synesthete was asked to identify the colours of several notes played on a piano, and then after a short period of discussion was played several more notes, however these colours were not noted, then the original group of notes were played again, and the colours noted to conform consistency. These notes were then sung over the names of different colours, and the synesthete was asked to identify the colour of the note that was being sung as it appeared to them as a result of their synesthesia. It was found that when the name of a colour being sung did not match the synesthetic colour it was common for the synesthete to have to pause for several seconds and try to distinguish the colour by separating the image created by hearing a colours name as well as experiencing a different colour as a result of the note.

  To most, the concept of being subject to involuntary experiences triggered by simple things such as letters or music is, at least, fascinating, and could even seem frightening in some cases. Synesthetes, in ninety-nine percent of cases, have had these experiences for as long as they can remember and therefore are used to them and become an intrinsic part of their lives. However, there is one type of sensory reaction many people experience, in some instances quite regularly. While not classified as synesthesia, due to the fact it is not cross modal, it is a vivid experience of a sensory quality that is indirect and which is not physically present. Auditory Replay is something that is common to most people as having a song ‘stuck in their head’, constantly repeating itself, especially a catchy jingle or motif.  While this does not involve any mixing of sensory experiences, this does, however, provide an insight into the involuntary nature of synesthetic experiences.

  There have been many famous composers, poets and writers that have not kept their synesthesia a secret, and have even used their abilities to great advantage in their work. Composers such as Franz Liszt:

‘When Liszt first began as Kapellmeister in Weimar (1842), it astonished members of the orchestra that he said: ‘O please, gentlemen, a little bluer, if you please! This tone type requires it!’ Or: ‘That is a deep violet, please, depend on it! Not so rose!’ First the orchestra believed Liszt just joked; later on, they got accustomed to the fact that the great musician seemed to see colours there, where there was only tones.’’ (Quoted from an anonymous article in the Neuen Berliner Musikzeitung, August 29, 1895; quoted in Mahling 1926, p. 230)

  Nikolai Rimsky-Korsakov had synesthetic colours for each of the musical keys, for instance C major was white, G was a brownish-gold, and B major was ‘A gloomy dark blue with the shine of steel’.

Jean Sibelius was another composer and musician who did not keep his synesthesia hidden:

‘For him there existed a strange, mysterious connection between sound and colour, between the most secret perceptions of the eye and ear. Everything he saw produced a corresponding impression on his ear- every impression of sound was transferred and fixed as colour on the retina of his eye and thence to his memory. And this he thought as natural, with as good reason as those who did not possess this facility called him crazy or affectedly original.

For this reason he only spoke of this in the strictest confidence and under a pledge of silence. “For otherwise they will make fun of me!”’ (Adolf Paul, 1890, as quoted in Ekman, 1938 pp.41-42)

Oliver Messiaen was himself a synesthete, as is quite well detailed in his own writings and interviews. Many of his compositions are influenced by this, such as ‘Olseaux Exotiques’. ‘L’ascension’ and ‘Couleurs de la cite celeste’, and they based around the concept of ‘producing pictures’, writing specific notes to produce specific colour sequences and blends.

Synesthesia has also featured in other forms of art, painting, poetry and prose. The artist Jane Mackay has colour-music synesthesia, and sees colours, shapes and textures when listening to different types of music, and uses these to paint a picture from these experiences. However not all of these claims are believed to be entirely true, and there is doubt surrounding the authenticity of certain artists synesthesia. For instance, Charles Baudilaire is known as merely a quintessential synesthete, as some of his work was drawn from the connection of different senses rather than what is commonly regarded as synesthesia, thus his work is commonly thought to have been inspired by induced synesthesia or metaphorical thinking, and is considered a romantic rather than a genuine synesthete.

Bibliography

Synesthesia – Perspectives from Cognitive Neuroscience – Lynn C. Robertson and Noam Sagiv, 2004

BBC Radio Four, Hearing Colours, Tasting Sounds 12^th & 19^th November 2002