Updated: Jun 8, 2021
Hearing colours, seeing or tasting sounds…
Thanks to the uniqueness of the organisation of the human brain, some people may experience the world differently.
Synaesthesia (Greek syn – ‘together’ and aesthesis – ‘perception’) is often represented as a rare neurological condition in which the senses are merged. In fact, synaesthesia is when one sense appears to co-occur with another sense, but in reality, one sensory experience is followed by an automatic, not related additional sensory experience.
In a nutshell, synaesthesia is the involuntary linking of sensations. People who experience synaesthesia are called synaesthetes and they are estimated to be around 2-5 per cent of the population according to the last research (Simner et al. 2006). Most synaesthetes enjoy the different way they perceive the world and, don't forget that for them this is the normal way of experiencing the environment.
Synaesthetes can feel colours/tastes/smells/shapes/textures and other sensory experiences, more abstract such as emotions. These experiences can arise during daily
activities such as eating, reading, walking, speaking, sitting, thinking, listening to music etc.
There are many different types of synaesthetes and thus, many different ways of synaesthesia (around two hundred and probably many more). Some people taste words (and this is characterised as lexical-gustatory synaesthesia), some see colours when they hear sounds (sound/music-colour synaesthesia) or when they taste foods (flavour-
colour synaesthesia) or when they touch different textures (touch-colour synaesthesia). Moreover, some can hear sounds when objects are moving slowly (visual-auditory synaesthesia).
This is an example of grapheme-colour synaesthesia. The letters or numbers are imbued with colours. For example, the letter C might trigger the colour green. 1 to 2 percent of the population have grapheme-colour synaesthesia (Simner, 2019).
Synaesthesia can occur in autism and in general, it is considered to be rare due to the fact that autistic people may not recognise that other people cannot feel colours/tastes/smells/shapes/textures, and thus, they believe that this is the normal way of perceiving the world. Another reason for the low incidence of synaesthesia in autism can be the fact that autistic children and adults may struggle to express their sensory experiences as a result of the dominant societal standards of 'normal.
In autism, touch-colour synaesthesia is quite common. Autistic people may look at something and then they can have a tactile experience without even touch the object. This can happen the other way round, for example, they can feel that are being touched when somebody looks at them or by sounds. This is described as a sound-feeling phenomenon.
The sensory sensation to the skin can be caused by sounds that other people cannot hear. For some autistic people, sounds can even cause the sensory experience of a hit and also some can experience the sounds both on their skin and represent visually at the same time. The auditory overload can result in visual chaos, confusion and difficulty to perceive the environment around them.
In 'two-way' synaesthesia (someone hears sounds when he sees colours and he sees colours when he hears sounds), the person can face daily challenges from the information overload (stress, dizziness) and therefore it can be beneficial to avoid colourful and noisy places. If the person is autistic and synaesthete, the sensory overload can be uncomfortable and complicated.
In particular, some children can face difficulties with the voice of teachers/parents/friends/others because the voice hurts or sends flashes of colour that interferes with their perception. On the other side, some children can be fascinated by the colour/voice and as a result, they cannot understand what someone is saying/become confused/stressed.
In this situation, you need to talk with simple words, doing frequent pauses so you can check that the child is following you.
Although synaesthetes can experience difficulties, they can perceive the world in depth and detail, feel texture and vibrancy through the multidimensional lens, resulting in original, creative and compelling pieces of artwork.
Van Gogh - Starry Night
Vincent Van Cogh described that sounds had colours and specific colours such as blue and yellow, were like fireworks for his senses.
Simner, J. (2019). Synaesthesia (Vol. 608). Oxford University Press, USA.
Simner, J., Mulvenna, C., Sagiv, N., Tsakanikos, E., Witherby, S. A., Fraser, C., & Ward, J. (2006). Synaesthesia: The prevalence of atypical cross-modal experiences. Perception, 35 (8), 1024-1033.