Synaesthesia Honours Project: Chasing a definition

Today I started to read first book about synaesthesia. Unfortunately, "Synaesthesia: A Very Short Introduction" (first on list) is scheduled to be released mid-2019 (seems that I overlooked that part or publication has changed recently) so I had to change order of books to read.

Thanks to my University I'm able to read "Sensory blending: On synaesthesia and related phenomena" straight from Oxford Scholarship Online. What I want to get out of this book is to understand concept and terminology of synaesthesia,

I read Chapter 1: Introduction.

As I expected it's difficult to standardize concept of the phenomenon. It's broad range of stimulus between different sense. Some can taste colours while others can see specific colours when they hear adequate sound – to mention just two. I’m not the only one who is trying to find a description of synaesthesia which will cover everything.

Richard Cytowic define “Synesthesia (Greek, syn = together + aisthesis = perception) is the involuntary physical experience of a cross-modal association. That is, the stimulation of one sensory modality reliably causes a perception in one or more different senses” (Cytowic, 1997) others as “anomalous sensory perception” (Asher et al., 2009). It’s phenomena not associated with any other particular pathology or dysfunction (but can co-exist with conditions like autism). Synaesthesia is not easy to classify as issue or disorder, more than that, recent studies suggest that stand as objection to standard theories of perception and mental processes. No wonder that synaesthesia is also a topic studied by philosophers. The more we look into it the more questions about our own senses and experience floats to the surface.

Brain activity has been studied and brought new light suggesting that our senses are not separated in a way that we thought they are so far. In auditory visual synaesthesia – a topic that I will focus on later in the project – sound that trigger colours for synesthete’s increase activity in fusiform gyrus V4 (or V8) (the area of the brain that is activated when non-synesthetes perceive colours). Yet, when non-synesthetes trained to associate colours with sound are trying to imagine colours this are of brain is not active.

Quoting author of the book: “synaesthesia is likely to be characterized more broadly as an increased cortical connectivity between various sensory brain regions, either directly or indirectly” (Deroy, 2017). Further study is necessary to be able to better understand what synaesthesia is and how to categorize this phenomenon.

Also new position was added to literature list: “Blue Cats and Chartreuse Kittens: How Synaesthetes Color their World” by P. L. Duffy.

References:

Asher, J. E., Lamb, J. A., Brocklebank, D., Cazier, J. B., Maestrini, E., Addis, L., Sen, M., Baron-Cohen, S., and Monaco, A. P. (2009) A whole-genome scan and fine-mapping linkage study of auditory-visual synesthesia reveals evidence of linkage to chromosomes 2q24, 5q33, 6p12, and 12p12. American Journal of Human Genetics, 84(2), 279–85.

Cytowic, R.E. (1997) Synesthesia: Phenomenology and neuropsychology. In S. Baron-Cohen (ed.), Synesthesia: Classic and Contemporary Readings (pp. 17-39). Oxford: Blackwell.

Duffy, P. L. (2001) Blue Cats and Chartreuse Kittens: How Synaesthetes Color their World. New York: times Books.

Bibliography:

Deroy, O. (2017). Sensory blending : On synaesthesia and related phenomena (First ed.).

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