Pharyngula

Synesthesia Neuroslam

Synesthesia is going to be the discussion topic for our upcoming neuroslam in two weeks. Synesthesia is the rare ability of a select few individuals to see numbers as colors or as in the article that I’m preparing to discuss (Hubbard 1996), experience varying degrees of light and dark as melodic intervals. The observed pattern is that individuals experience lower pitches or descending melodic intervals in correlation with darker stimuli and higher pitches or ascending melodic intervals in correlation with lighter stimuli. The important detail about synesthesia is that individuals experience it involuntarily whereas most individuals without synesthesia can choose to consider a set of stimuli using a secondary sense that they normally wouldn’t.

One of the experiments discussed in this article was conducted with undergraduate students coaxed into participating with the offer of some credit for an intro to psychology course. The students were placed in front of an Apple RGB color monitor and grey squares of differing light intensities were presented in conjunction with a perfect fifth for four seconds. Eight perfect fifths were used, each beginning on a different tonic and thus each having a unique frequency. The squares were presented on either a white or black background. The students then rated how similar the square and the interval were on a scale with one as the least and nine as the most. One of the questions considered with this experiment is the effect of contrast between the background and the grey squares on perception.

A second experiment was set up similar to the first experiment except that students (who had not participated in the first experiment) were presented with an interval at one of the selected frequencies and asked to choose among several light intensities of grey which correlated best. Correlating one perfect fifth to a light intensity that was presented with multiple light intensity options successfully diminished (no pun intended) the effects of background contrast on perception.

I thought of some questions when I was reading this article and then afterward studying for music theory. Are there individuals who experience synesthesia such that they correlate varying degrees and intensities of lightness with more complex types of music intervals? Do minor or diminished intervals correlate to a different light intensity than major or augmented intervals? What about different intervals of the same quality? Do ascending minor sixths correlate to a different light intensity than ascending minor thirds? If an individual with true synesthesia enters a concert hall do they experience sensory overload? (just kidding) I’m sure one of us neurobio students will post about neuroslam in a couple weeks to fill everyone in on our discussions but until then there is a lot of good reading on the subject.

References:

Timothy L. Hubbard. “Synesthesia-like mappings of lighness, pitch, and melodic interval.” American Journal of Psychology. 1996. v109n2: p219

Comments

  1. #1 wildlifer
    November 9, 2007

    One of PZ’s greatest fans at ARN was a synesthete. I made the mistake once of suggesting it was genetic, rather than a gift from God, and thought she was going to climb through the computer and scratch my eyes out. What a Joy she was.
    She posts over at TelicFarts now.

  2. #2 frog
    November 9, 2007

    Could synesthesia simply be a failed inhibition of natural cross-talk? Could it be we are all experiencing synesthesia constantly at a low level, but it doesn’t get reported to the frontal cortex from the parietal lobes, or where ever the cross talk is actually happening? Or that it happens quickly in the frontal lobes and gets immediately inhibited, leading to no memory of the experience? This should be experimentally testable with some clever psychological experiments.

  3. #3 R
    November 9, 2007

    How common is it? I’m a sound-synesthete and see sounds as varying types of moving colored shapes out there somewhere. It all seems natural to me and I was surprised when I realized not everybody sees it that way. But I think number-synesthesia is weird…

  4. #4 Anon
    November 9, 2007

    #6–Phosphenes

  5. #5 Dustin
    November 9, 2007

    I have an extremely dull form of synesthesia: when my eyes hurt (like I poke myself or something), I hear a sound like wind rushing past my head.

    Have you had that looked at by a doctor? I’m way out of my depth here, but that sounds like something that happened to someone I knew who had some kind of hypertension.

  6. #6 G
    November 9, 2007

    This is totally one of those things I wish I could experience. It would be so interesting to relate to the world in that way.

  7. #7 Murray Bowles
    November 9, 2007

    Has anyone investigated just how closely LSD-induced synesthesia resembles “real” synesthesia?

  8. #8 J. Edgar Hoover
    November 9, 2007

    I once smoked some potent weed and saw rainbows of sound as a result, so there may well be a “crosstalk” of sorts underlying synesthesia.

  9. #9 Will
    November 9, 2007

    Alexander Scriabin is probably the most famous composer with this condition. He perceived sounds as color, similar I guess to what Interrobang posts above. I’ve always taken it as a piece in a certain key has a preponderance of a particular color. There does seem to be a similar set of color to pitch cross-relations between people who perceive pitch as color. See http://en.wikipedia.org/wiki/Scriabin for a picture of the colors of pitches as Scriabin described them.

  10. #10 Carolyn
    November 9, 2007

    Synesthesia can also be provoked by LSD and other psychedelics; and, much less pleasantly, through migraines. As the migraine starts ramping up sounds cause color pulses and tactile pain. Likewise bright lights itch, and sunlight can burn.

    I’m sticking my head up from lurking to second other bill in #20. I haven’t a hint of synesthesia except during migraine episodes, at which point I perceive sound as light (and pain.) Loudness determines brightness, and the character of the sound determines the shape. During one particularly bad headache in middle school, I complained until my mother changed the bedsheets, since the texture felt “too bright.”

    I find the idea of synesthesia fascinating in theory, but I would gladly trade the experience for not having migraines. :\

  11. #11 ShockedISaid
    November 9, 2007

    I am a music/smell synesthete. I have mentioned it rarely to people and, when I have, they mostly thought I was nuts. Out of curiosity once, I talked to one doctor about it. He didn’t know what I was talking about. Sigh.

    I do not see colors for all pitches, but for a fair number. The colors are always the same for the same pitch. For me, it works as a type of perfect pitch. I experience smells with pitches, also, but these are not nearly as clearly defined as the colors.

    Many moons ago, I used to be a professional trumpet player. I experienced synesthesia only when listening and never when playing.

    For those of you who don’t have non-pain related synesthesia, you’re missing out. It’s really quite a lot of fun. For me, the colors and smells are always pleasant. Maybe that’s one of the reasons I like music so much.

  12. #12 frog
    November 9, 2007

    For letter-synesthiasists out there: Is the link between letters and colors for example, just a visual link, or is it also evoked phonetically? Does the sound of the letter link to the color of the letter as well, or is the phonetic effects completely disjoint from the literary effects?

    The answer would be interesting in terms of the wiring topology of these systems.

  13. #13 ennui
    November 9, 2007

    http://www.journals.royalsoc.ac.uk/content/5mf8ydm183nv7fcn/fulltext.pdf

    http://www.ted.com/index.php/speakers/view/id/164

    The above links relate to V.S. Ramachandran’s work on the subject. I would also recommend ‘The Man Who Tasted Shapes’ by Richard Cytowic as a primer.

    I personally know 2 people with the tone/color variety. Fascinating stuff…

  14. #14 ennui
    November 9, 2007

    There is a very good summary of the neural basis of the phenomenon at Wiki:

    http://en.wikipedia.org/wiki/Neural_basis_of_synesthesia

  15. #15 Buffybot
    November 9, 2007

    Sorta-kinda responding to Owlmirror – I’d ask some of the same questions. One of the things with synaesthesia is that it’s completely individual and subjective. It’s like the idea that we can never know if the colour we perceive as ‘red’ is exactly the same for both of us. So, I can only speak from my own experience, because I’ve no idea what weirdness is going on in other people’s brains. As for different alphabets, I now really, really want to know how this works for people with pictogram (if that’s the word) alphabets, like Chinese.

    As for letters being different depending on the typeface or whatever; I see the letter on paper as it’s printed or written. But if I’m picturing a letter or word in my mind, it has it’s associations. The number five can be printed in any style and colour, and that’s what I’ll see, but if I’m remembering a phone number or something, then it’s bright orange on a background of bright yellow. I see the symbol 5 like that in my mind, but a random splotch of a certain shade of orange on the yellow background also means ‘five’. An artist friend once sat me down with pastels to draw all the numbers. She noticed, but I didn’t, that I’d drawn half the symbols backwards, because in my mind the colours are more strongly associated than the symbol.

    Geometric shapes – sort of. They’re vaguely emotionally different in a way I can’t quite pin down, but it sort of hinges on how many sides they have and whether they’re made up of straight lines.

    Days of the week – have their own colours and personalities. Do other synaesthetes divide things into odd/even and positive/negative that don’t really have those divisions? To me, letters of the alphabet are divided into odd/even like numbers, but they don’t necessarily alternate.

  16. #16 Becca
    November 9, 2007

    “The above links relate to V.S. Ramachandran’s work on the subject. I would also recommend ‘The Man Who Tasted Shapes’ by Richard Cytowic as a primer.”

    I’m sight/sound synaesthetic (and, in fact, am briefly mentioned in the Cytowic book). What is amusing is that the birth-mother of my children is color/touch synaesthetic, something neither of us knew about the other when she made the decision to let me adopt her children. Alas, neither of the children seem to have inherited it in any form.

    I was 18 before I knew there was a word for it, and found it very validating (“see, Mom, I’m not just making it up! There’s a word for it, so it must be real!”). I still mostly don’t mention it to anyone.

  17. #17 Becca
    November 9, 2007

    “The above links relate to V.S. Ramachandran’s work on the subject. I would also recommend ‘The Man Who Tasted Shapes’ by Richard Cytowic as a primer.”

    I’m sight/sound synaesthetic (and, in fact, am briefly mentioned in the Cytowic book). What is amusing is that the birth-mother of my children is color/touch synaesthetic, something neither of us knew about the other when she made the decision to let me adopt her children. Alas, neither of the children seem to have inherited it in any form.

    I was 18 before I knew there was a word for it, and found it very validating (“see, Mom, I’m not just making it up! There’s a word for it, so it must be real!”). I still mostly don’t mention it to anyone.

  18. #18 Rjaye
    November 9, 2007

    I didn’t know that synesthesia was rare until I saw a special on PBS about it, and was flabbergasted. I thought everyone had it! It never occurred to me it was unusual.

    I have mixed synesthesia of various forms. Sounds have different tastes, different textures, different colors. It’s just how I sense the world.

    And given how many synesthetists are reporting here, one could do a study.

  19. #19 Qalmlea
    November 10, 2007

    @#38

    For letter-synesthiasists out there: Is the link between letters and colors for example, just a visual link, or is it also evoked phonetically? Does the sound of the letter link to the color of the letter as well, or is the phonetic effects completely disjoint from the literary effects?

    For me, just about everything has a color. Letters, shapes, sounds, tastes, music especially. And I realized only recently that there are some oddities. The symbol ’8′ is a deep blue, with a hint of purple. The word ‘eight’ is kinda yellowish brown, and the word ‘ate’ is mostly red. I couldn’t tell you why, except that ‘e’s tend to make words yellower and ‘a’s tend to make them redder.

    Like many others, I had no clue that there was anything odd about my color perceptions, except that people would give me odd looks when I described Celtic music as “green and gold” or hard rock as “red and black.” Country tends to have lots of yellows and browns. Also, the colors were sharper for music in a minor key than in a major key, so I always preferred minor.

  20. #20 Eric Paulsen
    November 10, 2007

    When I was maybe 10 or 11 I had a singular incidence of synesthesia while my babysitter was reading me a story in an effort to get me to go to sleep. I have never forgotten it because I was mesmerized for the few seconds it was occurring, it was like seeing true magic if only for an instant! I saw glowing neon shapes and colors popping like sparks around her mouth while her voice receded into the distance like a radio being tuned to static, it was both frightening and beautiful.

    My guess is that I suffered from transient TLE for period of some years while I was growing up because there was more than just that episode of synesthesia, like a few choice visual and auditory hallucinations. There was even an instance where a plate flew out of the kitchen cupboard over my shoulder to break on the floor behind me, if I hadn’t been reaching for it when it happened and therefore looking right at it I wouldn’t have believed it.

    That said I do not believe in boogens or ESP, magic or religion. I firmly believe that everything I experienced was due to 5 pounds of misfiring meat in my braincase.

    That doesn’t make the experiences any less awe inspiring though.

  21. #21 J Myers
    November 10, 2007

    I associate colors to letters and numerals, but I would guess this is some lingering effect of Sesame Street and the colored magnet letters that I stuck to the refrigerator as a child; I do not see these colors as though they were appearing in the real world (“k” is grey for me–David, is that correct?). Some associations are stronger than others; from an example above, for me: a=dark yellow, t=brown, e=dark blue, though the word “ate” itself does not evoke any colors (nor does any other word).

    Interrobang, do you have absolute pitch? Can you actually hear the sound of a dog whistle, or do you only perceive the color? Wouldn’t the appropriate visual analog be UV, not IR, or is that contrary to your perceived color/pitch association?

    Does anyone perceive colors as sounds? (e.g., green might cause you to hear an F# or something).

  22. #22 RamblinDude
    November 10, 2007

    I also remember that show about the guy with the phenomenal mathematical ability in #5. He was an interesting study because he wasn’t, as was usually the case, mentally handicapped. He said that the number nine was a very “tall” feeling. When he went to New York he was surrounded by number nines.

    A Japanese friend told me one time that Orientals hear things is a different way than occidentals do, and that that was one of the reasons the Chinese language was very dependent on pitch. He said that high tones, like that produced with wind chimes, gave a “cooling” effect in a way that we just didn’t get. He joked and said that in the orient they some times referred to wind chimes as ‘air conditioners’. That would certainly save on electricity. : )

    I don’t have synesthesia, at least not more than the average person, I think, but the days of the week always reminded me of colors. Wednesday is a light straw brown, Friday is a darker brown, Sunday is whitish and Saturday is blackish. Tuesday and Thursday are dark colors but I can’t really describe them.

    I always wondered what early memories cued this relationship,

  23. #23 RamblinDude
    November 10, 2007

    Oh, Monday is a pinkish red. : – D

  24. #24 Leigh
    November 10, 2007

    I’ve never thought of myself as a synesthetic, but for me smells have both color and shape. I don’t actually see these when I smell something, but when I describe it, I get a visual of the shape and color and that’s how I describe the smell. The perfume I wear, for example, has crisp edges and is a golden bronze-green. I think I started this when I began having migraines, though I hadn’t really connected the two. I did go to one concert with the start of a migraine (I was feeling the unease of onset, but hoped it would hold off); surely, I thought, some gentle classical music would soothe me. But the concert featured a lot of trumpet flourishes that just overwhelmed me with pain; it was just like being assaulted, and I became a little panicky and fled the room. Those trumpets were edged weapons, folks! I’ve heard that the latest info on migraines likens them to a spreading electrical storm in the brain; I suppose that might explain how areas of sensory interpretation might get cross-connected. I’m following that research with some interest.

  25. #25 uncle frogy
    November 10, 2007

    I have not thought of this in a long time. In my younger days back in 1960′s I tried LSD a few times. My own impression of the experience was that the thresh holds of the the senses and brain were reduced making it very hard to keep things straight as to what I was seeing, hearing, smelling or feeling. Thinking became seeing became hearing became seeing became smelling. As if I was suddenly reduced to an infant and just started to use my body and was rather overwhelmed by it but was at the same time my real age . It was very difficult to do anything like drive some where. I am glad that at the time I had nothing I needed to do.

    If that is anything like Synesthesia it could be very problematic I will stick to having a “normal sensory” experience thank you. though it does suggest the possibility of new art forms. I do not see any useful survival benefits in it but not sure if there are any negative aspects though being overwhelmed by your senses could get you killed pretty fast.

  26. #26 uncle frogy
    November 10, 2007

    I have not thought of this in a long time. In my younger days back in 1960′s I tried LSD a few times. My own impression of the experience was that the thresh holds of the the senses and brain were reduced making it very hard to keep things straight as to what I was seeing, hearing, smelling or feeling. Thinking became seeing became hearing became seeing became smelling. As if I was suddenly reduced to an infant and just started to use my body and was rather overwhelmed by it but was at the same time my real age . It was very difficult to do anything like drive some where. I am glad that at the time I had nothing I needed to do.

    If that is anything like Synesthesia it could be very problematic I will stick to having a “normal sensory” experience thank you. though it does suggest the possibility of new art forms. I do not see any useful survival benefits in it but not sure if there are any negative aspects though being overwhelmed by your senses could get you killed pretty fast.

  27. #27 Buffybot
    November 10, 2007

    Leigh – sometime in the past 10 years New Scientist did an article on synaesthesia called “The Sweet Smell of Purple”.

    Answering Owlmirror’s question – words have their own vibe which is a combination of the letters, but all swirled together and with some predominating. Pharyngula is a really pleasant word for me – all curly, soft and smooth. Imagine a rococo whipped cream sculpture in shades of lilac, sage, pink and white. P, G, and R are stong-coloured assertive-type letters, but the y and the ula have a kind of diluting effect and make it all pastelly. Putting the letter L in a word is like pouring milk into soup.

  28. #28 Joolya
    November 10, 2007

    For me, the word “Pharyngula” is reddish-pink (because /p/ and /a/ and /r/ are pink and red) with brown (/g/) and purple (/u) undertones, and reminiscent of a plum (yellow inside for /y/ and /l/). It’s also a feminine word because the majority of its letters are female (p, h, a, r, y, and u).
    But “PZ” is pepto-bismol pink and licorice black.
    Maybe I am different from more “strong” synesthetes, though, because I don’t “see” the colors … I would descibe it as “tasting” the colors on the back of my palate, but that doesn’t really make it more clear! I can also dial it up or down, depending on how I feel and if I am paying attention to it or to, e.g., the actual words I am reading, like in a book or on a blog.
    When I was a kid I would take a long time over my math homework, because I was too busy making up stories about the numbers in the problems to actually solve them. All the numbers had colors, gender, and personalities. For example, the number 36 is a married couple that are fighting (the more outspoken bright green female 3 and the stolid brown mister 6 have their backs to each other); 42 are gossiping girls (dark blue 4 is older, wiser, than little pink 2); 97 (he likes her but she thinks he’s arrogant).
    I always thought my associating capacity was just a bit more active than the average, so the extra-connectedness of neurons seems to make sense to me. It’s very interesting to compare notes with others here!

  29. #29 Bee
    November 10, 2007

    Owlmirror #67

    Thanks for the explanation.

    To your last question, I have to answer that I don’t know, because I’ve never considered that aspect of it. However, I’ve taught myself to play guitar over the past year and a half and perhaps I should try to notice whether there’s any consistency to the imagery, now that I’m producing the sounds myself.

  30. #30 usagi
    November 10, 2007

    One more link on the topic for you:
    http://cosmicvariance.com/2007/11/05/martian-colors/
    Synchronicity’s a funny thing, isn’t it?

  31. #31 Buffybot
    November 11, 2007

    Somewhere-or-other I’ve heard/read/seen in a TV documentary that all babies have synaesthesia, but that most people outgrow it in early childhood, which may explain Bee’s experience.

    I love Joolya’s numbers soap-opera. I’m like that with the alphabet. Letters are divided into odd and even, like numbers, but in addition they have colours, moods and personalities. Within the alphabet there are lots of cliques, animosities and partnerships. O is lonely without its soulmate U. R is two-faced and untrustworthy (what else would you expect from a green letter?), but W is kind, jovial and tastes of pencils.