"'A' tastes like blueberries..."

As Norton Juster, master of wordplay, delved into the childhood experiences that shaped the Forest of Sight, the Foothills of Confusion, and the magical cities and municipalities of the Lands Beyond, a curious neurological phenomenon unveiled a new world of perception as vivid and striking as Chroma's symphony of colour. This peculiar neurological condition which involves the involuntary merging of one or more sensory modalities is termed syn(a)esthesia and is etymologically derived from the ancient Greek σύν (together) and αἴσθησις (sensation). While Norton Juster recalls his association of numbers and colours ("4 was blue, 7 was black") Vladimir Nabokov spoke of "colour hearing": 

Both Nabokov and Juster have illustrated a phenomenon which demonstrates the significance of artists and researchers in the humanities as co-investigators of human consciousness. The challenging hypothesis that a viewer's or reader's reception of art can be explicated by a set of neural correlates comprises the object of investigation for the burgeoning field of Neuroesthetics. Neuroscientists (Zeki, 2001) believe the aesthetic experience is well within our reach, and can be fully understood in neural terms. However, taking into account the impossibility of defining and confining art within the domains of neuroscience, is this a safe assumption to make?

Though few authors have mapped their experience of grapheme-colour syneshesia as methodically and accurately as Nabokov, multiple synesthesia is not as rare or curious a phenomenon as one might think. As Anderson's adolescent protagonist Mia contemplates, "About four percent of the population- one in twenty-three people- have some form of synesthesia...all it means is that your senses are interconnected, or cross-wired, so that when one sense is stimulated one or more other senses respond at the same time" (Anderson, 2011, p. 115). 

A recent study at the University of California, published in the August issue of Psychological Science has revealed the possibility that we are all born synesthetes, yet the exuberant neural connectivity that  influences shape-colour associations in infants is gradually eliminated through the process of retraction and reweighing of connections over the course of development. Failure of the retraction process may, in rare cases, lead to adult synesthesia. Simon Baron-Cohen (1996) also supports Maurer's developmental theory of synesthesia, stating that all human neonates are synesthetic and that typically, at about four months of age the senses have become modularised to the extent that we no longer experience an interconnectedness of the senses. 

Some of my earliest memories of reading are associated with taste. At around the age of five I remember associating the Greek letter -η (eta) with a zesty flavour, and for some time the appeal of specific poems and fairy tales depended on the richness of the taste evoked. Some of Zorz Sari's novels and short stories were so mouthwatering that my concentration often wavered from the plot and character development (this can prove especially troublesome when answering questions or writing essays in class!).

John Locke's (1960) synesthetic account in his Essay Concerning Human Understanding is often cited as the earliest reference to synesthesia. However the capacity for sensory crosstalk dates back to the Pythagorians (550 B.C.) who correlated mathematical equations with musical scales as part of their belief that a universal philosophy could be founded in numbers. Johannes Kepler subsequently drew from the Pythagorian and Platonic notions of orbital resonance to delineate his theory of celestial harmony (Harmonices Mundi, 1619).

While the question of whether neuroscience can aptly define the aesthetic experience remains a highly controversial subject, less contended is the notion that art contains much knowledge about the brain and that the artist holds the key to unlocking real, tangible truths about the human mind. 

Images of the synesthete in literature have led to a resurgence of interest in the genetic factors that lead to synesthesia. In a 1962 interview with the BBC, Nabokov revealed that while he perceives the letter 'M' as pink, his wife, also a synesthete, associated 'M' with blue. Intriguingly, their young son Dmitry would later remark that the letter 'M' is purple, "as if genes were painting in aquarelle". 

Young adult novels containing synesthete protagonists such as Wendy Mass's (2003) A Mango-Shaped Space and Anderson's (2011) Ultraviolet have been praised by synesthetes and academic researchers of synesthesia. Wendy Mass's protagonist Mia associates colours with letters, numbers, and sounds. An unfortunate incident at school wherein Mia's unorthodox (and colourful) approach to a mathematical problem is rejected by her teacher forms the catalyst that leads to her diagnosis and understanding of her condition. The title of the book refers to Mia's cat 'Mango the Magnificat' (Mango, for short) whose purring and meowing represent different shades of yellow and orange for Mia, like a mango in its various seasons. 

Anderson's (2011) rather ambiguous protagonist, Alison narrates a tale of descent into madness. The first chapter of Ultraviolet opens with Alison attempting to reconstruct her fragmented memory as an involuntary patient in a mental facility. It is in this cold, clinical environment that the protagonist confessed to the murder of her classmate and becomes cognizant of her ability to feel the 'trustworthiness' of letters and words. Ultraviolet and A Mango-Shaped Space occupy two distinct categories in Patricia Lynne Duffy's (2006) constructions of literary synesthetes. Synesthesia in Ultraviolet is represented as "romantic pathology", whereas in Mango, the ability to perceive synesthetically represents health and balance for Mia. 

Investigating synesthesia through artistic expression may lead to an understanding of the "binding problem" (Cytowic, 2009). Limbic theories of synesthesia attribute such patterns to the limbic system, primarily responsible for the regulation of emotional responses. However, functional magnetic resonance imaging of coloured-hearing synesthesia (Baron-Cohen et. al, 2002) has indicated significant activity in the cerebral cortex: while areas of the visual cortex associated with processing colour are activated when coloured-hearing synesthetes listen to words, non-synesthetes do not show activity in these areas, even when instructed to imagine colours or associate certain words and colours. 

Research in this fascinating area may lead to an understanding of how the human brain makes sense of the world, that is, how the results of the various stimuli we are exposed to create multiple "fragmentary drafts" within their specialist neural circuits, leading to the creation of narrative-like sequences or scripts (Dennet, 1992). A cognitive poetic approach to young adult fiction proffers different literary investigations into the reader's 'poetic competence' and the cognitive processes underlying the reading experience: this burgeoning dialogue between cognitive psychology and literary studies has truly elucidated the architecture of the infinite mind.

This blog post was inspired by Norton Juster's recollections of his childhood experience of grapheme-colour synesthesia, which he recently spoke about during his seminar at the Cambridge/Homerton Research and Teaching Centre for Children's Literature.

:-) Fun fact: American singer and songwriter Lady Gaga has also described how she envisages sounds "like a wall of colour" and how her song poker face is a "deep amber colour"(!)

Works Cited:

• Anderson, R. J. (2011). Ultraviolet. London: Orchard.
• Baron-Cohen, S. (1996). Is There a Normal Phase of Synaesthesia in Development?, PSYCHE, 2(27).
• Baron-Cohen, S. & Harrison, J. E. (1997). Synaesthesia: Classic and Contemporary Readings. Oxford: Blackwell.
• Dennett, D. C. (1992). Consciousness Explained. London: Penguin.
• Juster, N. (1961/1999). The Phantom Tollbooth. London: Collins.
• Mass, W. (2003). A Mango-Shaped Space. London: Little, Brown.
• Nabokov, V. (1957/1998). Speak, Memory. London: Penguin.
• Wagner, K. & Dobkins, K. R. (2011). Synaesthetic Associations Decrease During Infancy, Psychological Science, 22(8), 1067-1072.