Friday, July 17, 2009

Synesthesia: the neurological disorder you wish you had

Lately I’ve been thinking1 about synethesia. Synethesia is a neurological condition in which there is a mix-up between the senses, whereby the person will experience things described as “tasting colour” or “feeling sound” (i.e. when they experience a taste, a colourful aura specific to the taste will appear in front of their eyes).  I’ve included a couple videos here which give an idea what this condition is like. The first video is a snappy overview of what synethesia is all about. Personally I think the condition is exemplified best at the end of the clip when it shows a guy eating chicken with vanilla ice cream and orange sauce on it with a big smile on his face as a whole bunch of blue colours come up in front of his eyes.  The second video is a TED talk from superstar neurologist VS Ramachandran talking about a whole bunch of things which are all very cool, but he starts talking about synethesia around 17:45, if you only want to hear about that. He brings up a cool point right near the end about how we all have synethesia to a certain extent. Please enjoy:

Synethesia is one of things which makes neuroscience really interesting to me, because it leads to so many questions. Questions such as, if these people can live essentially normal lives with the condition, what is the evolutionary advantage to not having synethesia? Is it really only a result of a faulty gene, or a couple of faulty genes, and if so, could we engineer synethesia genes and demonstrate them in an animal model? Is it something that we all have lying dormant in our brains, and can we somehow “tap in” to it? And lastly, why not me? 

Dr. Richard Cytowic (the author of the book that I got) argues that synethesia is actually a normal brain function that we all have, but only a small percentage of people are actually conscious of it. He gives a few examples where “normal” people can/may experience synethesia-like effects, including deep meditation, LSD induced hallucinations and also he mentions a case where a guy had a tumor of the left medial temporal lobe, who would see colours when hearing certain frequencies. Upon removing the tumor he could no longer experience any sort of synethetic effects.

So if synethesia is potentially lingering in all of our brains, can we train ourselves to become synethetic? Beats me. But I did have an idea to test it out. I think it would be interesting to create a keyboard with a big screen right in front of it, which would display auras of colours on it, each colour representing a different note. For example, E could be yellow, and an E major chord could be predominantly yellow with the other colours for G# and B subtlety mixed in.  If you were to start from childhood and learn to play the piano like this, I wonder if the association of colour and sound would become cemented in the brain, and whether or not this association would be transferred to listening to music on a CD or in a concert or even just ambient noise?

Synethesia is an interesting case of what the human brain can be capable of, and one of the many cases where I wonder why the mass of neurons in my head can’t do it, while the neurons in someone else’s head can. Perhaps someday we will have a better understanding of how the brain works, and how synethetic experiences arise. Until then however, the rest of us will just have to stick to LSD.


1 and by thinking I mean I got a book out of the library about synethesia and put it on my desk.


  1. Steve, I miss your thought provoking lunch discussions. Life seems incomplete without them.

  2. Its definitely a very intriguing subject. What is the book called?
    I would also lean towards it being something that can be learned. Although it may run in families it may only make them more prone to it, where as the plasticity of the brain plays a more major role. In any case, an experiment like your could help answer the question. Also, I believe this is how some people learn to have perfect pitch, that is by color/sounds association, maybe there are already subjects out there who have attempted this.

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  4. 2 things:

    Can it really be called a disorder? It doesn't seem to have that much of a drawback, save odd dietary choices.

    Based on a single experience, I can believe that anyone has the ability, though perhaps under very specialized conditions. I'd never given it much thought, but maybe I should try to recreate the effect. I'll get back to you on that.

    Check out on synesthesia, I think you'll appreciate it.

  5. regarding your question of what the evolutionary advantage of not having it is:

    1) its important to keep in mind that a lot of genetic changes might not really be an advantage or disadvantage, so it doesn't dominate or get phased out. In this case, I'd wager that it probably isn't such a huge factor that it'd be immediately evident what roll it plays in evolution, and we haven't been here long enough for that trait to run its course. Its unlikely at this point that its going to get integrated or phased out, since our natural evolution has slowed to a crawl.

    2) If there is a reason that it was mostly evolutionarily phased out, id argue that maybe it wouldn't be that beneficial to always have distractions floating across your vision. based on the comparisn to LSD induced halucinations, I assume these colours are obscuring ordinary vision.

    In regards to your experiment, i think it would be important to first determine if all synesthiates (sp?) associate the same colour with the same sound. as far as i know, this isn't the case. This could be a problem with your experiment. If everyone was taught with this keyboard/screen apparatus, they'd all theoretically associate the same colours with the same notes, and it wouldn't be the same as true synesthesia. It would beg a lot of other questions, mainly, why do people associate certain colours with certain notes?