Imagine a world where you taste words, where sounds have distinctive shapes and observing touch to a stranger would feel like a real touch on your own body. Although it might sound like a trailer of an upcoming sci-fi film, these extraordinary experiences are not fictional at all. In fact, these are pretty typical sensations experienced by about 4% of the population. Those fortunate enough to have such unusual experiences are synaesthetes.
Synaesthesia literally means ‘the union of the senses’ and is defined as a condition where stimulation of one sensory modality elicits involuntary additional percepts within the same or different modality, which typically does not occur for most of us. For example, in grapheme-colour synaesthesia letters or numbers printed in black trigger secondary colour percepts such that, for example, letter A is perceived as red or number 8 as green. The authenticity of synaesthesia is firmly established and many types of this condition have been identified so far. These include spatial sequence synaesthesia, where days, months or numbers occupy a specific location in space around a synaesthete; swimming style – colour synaesthesia or lexical-gustatory synaesthesia where words produce distinctive flavours accompanied by temperature and texture. One of the subtypes of synaesthesia which I personally find to be one of the most intriguing is mirror- touch synaesthesia (MTS) where watching someone else being touched produces a tactile sensation on a syanesthete’s own body as if they were being touched themselves.
Apart from investigating the mechanisms driving this extraordinary phenomenon scientists have also been researching broader traits linked to synaesthesia. Some of the wider differences associated with this condition include better memory, superior sensory processing as well as creativity. In terms of mirror touch synaesthesia, recent studies have demonstrated greater empathy as well as superior emotion recognition ability in this group.
Not surprisingly, going through life enriched by these extraordinary sensory experiences meant that many synaesthetes have become artists, writers and musicians. For instance, Vladimir Nabokov had grapheme-colour synaesthesia and this is how he described some of his sensations in his autobiographical book Speak Memory (1966): “The long a of the English alphabet has for me the tint of weathered wood, but a French a evokes polished ebony. This black group also includes hard g (vulcanized rubber) and r (a sooty rag bag being ripped). Oatmeal n, noodle-limp l, and the ivory-backed hand mirror of o take care of the whites.” Other notable synaesthetes include artists such as David Hockney or Wassily Kandynski, musician Pharell Williams or a famous mnemonist Salomon Szereszewski.
My research aims to further establish the mechanisms underlying this fascinating phenomenon. Specficially, I am interested in investigating the neural basis of self-other distinction which has been hypothesised to be atypical in mirror-touch synaesthesia. I am also investigating personality characteristics associated with synaesthesia as well as neural basis of emotion recognition, which has also been shown to be superior in MTS.
Although our understanding of this condition is still fairly limited, what scientific investigations into the fascinating world of syneasthesia have shown is that there are many ways to experience the world and that our perception of it differs to a greater extent than we could ever imagine.
About the author:
Agnieszka Janik is a PhD candidate at the Psychology Department at Goldsmiths University of London. She was awarded a scholarship by the Economic and Social Research Council to complete her doctoral studies. The main focus of her thesis is on the neurocognitive basis of synaesthesia and its implications for social cognition and cross-modal interactions in perception. In her research she implements electrophysiological techniques, non-invasive brain stimulation, and psychophysics.