Inducing Auditory-to-Visual Synesthesia I recently watched an interesting video that was discussing conveying color to the blind through language. It implied that there may be a way to insert the sensation of color into a person's mind via a series of sounds.

I have looked for articles on this and haven't been able to find much. I was just curious:


Is it possible to induce a kind of auditory-to-visual synesthesia?
Are there any articles on this?


Link to video:
http://www.youtube.com/watch?v=evQsOFQju08

Yes I know :)
First, a definition: "Synaesthesia is a curious condition in which an otherwise normal person experiences sensations in one modality when a second modality is stimulated." [1] There are two basic explanations for this phenomenon: the hyperconnectivity
hypothesis and the disinhibition-unmasking hypothesis [2]. The former says that the condition results from excessive neural connections between two modalities, and the latter says that it results from a lack of inhibition of signals. A quick search reveals that it is indeed possible to induce this condition (with drugs, for example), and it isn't necessary to rewire any neural connections [2,3,4]. This is an example of how the brain transmits/filters information by many mechanisms, connectivity being just one of them. 

[1] Ramachandran, Vilayanur S., and Edward M. Hubbard. "Synaesthesia--a window into perception, thought and language." Journal of consciousness studies 8.12 (2001): 3-34.

[2] Kadosh, Roi Cohen, et al. "Induced cross-modal synaesthetic experience without abnormal neuronal connections." Psychological Science 20.2 (2009): 258-265.

[3] Ramachandran, Vilayanur S., and Diane Rogers-Ramachandran. "Synaesthesia in phantom limbs induced with mirrors." Proceedings of the Royal Society of London. Series B: Biological Sciences 263.1369 (1996): 377-386.

[4] Luke, David P., and Devin B. Terhune. "The induction of synaesthesia with chemical agents: a systematic review." Frontiers in psychology 4 (2013).