Synaesthesia

 

Synaesthesia

                             Image courtesy Wikimedia Commons

Professor Jim Al-Khalili is Professor of Theoretical Physics at the University of Surrey. He hosts a programme on BBC called The Life Scientific, in which scientists are invited to talk about their life and work.

The broadcasts are interesting because the scientific experts speak clearly and articulately about their fields in a way that is readily understood.

A recent podcast featured Julia Simner, a Professor of Psychology. She has led research to understand how brains process the sensory world.  The main part of the programme was about synaesthesia, which is the merging or cross-over of senses. For example, when one sense is stimulated, like hearing, another sense is involuntarily engaged. One in twenty-three people has synaesthesia – roughly 4% of the population.

One of the most common forms is grapheme-colour synaesthesia, when letters or numbers, sometimes both, are associated with specific colours. It has been suggested that this arises because of early exposure to coloured alphabets or number charts or toys in infancy, but this is not proved.

Another type of synaesthesia is chromaesthesia, in which people see colours when listening to music. Van Gogh is believed to have experienced this, to the extent that he had to abandon piano lessons. 

In one of his letters, he gave evidence of another way in which synaesthesia affected him, when he said, ‘some artists have a nervous hand at drawing, which gives their technique something of the sound peculiar to a violin.’

Some people have lexical-gustatory synaesthesia. For them, hearing a word may deliver a taste sensation, not necessarily associated with food per se. For instance, the word ‘plum’ may initially evoke a mouth-watering response, but over time, just the ‘um’ sound or phoneme may produce the same result in words like, hum, bumble bee, umbrella, sum, crumb. In this form of synaesthesia, the phoneme (sound) may induce an unpleasant taste, depending on the association. Julia Simner prefers to be called Jules (Jools) but one person she knows is unable to call her that because of the disagreeable association with the ’oo’ phoneme.

Another very common type of synaesthesia is day-colour, in which people connect colours with the days of the week. Tuesday may be orange and Sunday blue, and so forth.

One remarkably interesting form is mirror-touch synaesthesia, when someone sees something happening to another person and feels it physically, too.

Synaesthesia is inherited, though the form it takes may differ between family members.

I have known one or two people who admitted to a form of grapheme-colour synaesthesia. They seemed to think it was linked to early reading experiences.

Do you have any experience of synaesthesia? Have you ever thought a particular letter or number had a specific colour?

                            Image courtesy Wikimedia Commons