Atypical Minds: the Cognitive Science of Difference and Potentialities
Cognitio 2015
Young researchers conference in cognitive science
Montréal, June 8th, 9th and 10th 2015
Synesthesia as Typical Conscious Experience
Michael Rawb Leon-Carlyle.
The nature of synesthesia is commonly disputed, with subjects who report synesthetic experience alternately being labelled “typical,” “atypical,” or even “defective.” Martino and Marks (2001) posit there is an overlap between the cross-sensory experiences reported by subjects with “strong” or “canonical” synesthesia and the general population’s ability to identify and appreciate cross-sensory associations, which they term “weak” synesthesia. Synesthesia, for Martino and Marks, encompasses a phenomenon experienced by both typical and atypical minds. Directly opposed to this claim are those, such as Deroy and Spence, who assert that we are not all synesthetes – not even weakly so (2013). To these researchers, the term synesthesia should only ever be applied to “strong synesthesia,” which would be a strictly atypical condition. Citing the work of Maurice Merleau-Ponty, I offer a philosophical argument in favour of calling the synesthete’s mind a typical mind.
An example of strong synesthesia would be vividly experiencing a certain colour in response to hearing a particular musical tone or timbre, or perceiving black print graphemes as having specific colours; an example of weak synesthesia would be a general correspondence between musical pitch and visual lightness – a correspondence that can be identified with non-synesthetes (Marks, 1978). The strong synesthetic experience is automatic, involuntary, and reported as being “literal” by the synesthete (Martino & Marks, 2001). If I have a synesthetic experience of sound to colour, I do not merely conjecture that the sound of a violin resembles the colour blue in some way – rather, I readily report that the sound of the violin is blue as I would the afternoon sky. I know the text on the page is printed in black ink, but the individual letters number leap out at me in red, blue, or green; as I struggle to remember an address or phone number, I recall the digits being scarlet and gold. Weak synesthesia, on the other hand, manifests in metaphor, artistic license, and forced-choice batteries: if the subject must identify a high-pitched sound with either a black or white visual, they will choose the visual after some consideration (Marks’ work suggests they will likely pick the white visual in this instance).
In the Phenomenology of Perception (1945), Merleau-Ponty conflates strong and weak synesthesia when he claims that all perception (for the typical human subject) is synesthetic. Cross-sensory experience, he argues, is something automatically accomplished by the human body, and the individual strata of sensation (vision, hearing, etc.) are only separated from each other in consciousness once the subject focuses upon a particular sense and removes him or herself from primordial, originary perception. Even if I hear a sound belonging to something I do not see, I am always conscious that the sound is a sound of something – something that I can choose to investigate and experience with my other senses. Even if it is granted that experience is formed from wholly separate sensory modalities, perceptual experience of the world only arises where these senses “gear into each other” such that this sound, this visual, and this texture all belong to one object.
For the synesthete, the colour blue literally belongs to the violin’s sound exactly as the smooth texture of polished wood belongs to the violin’s material. In both the synesthete and the non-synesthete, consciousness of the world automatically emerges where senses collide and intersect, like mountains formed by tectonic plates. Synesthesia is a typical activity of consciousness as it takes in sensory data. If strong and weak synesthesia do not belong on the same spectrum, it is because weak synesthesia concerns conjecture rather than automatic synthesis of sensation.