Synesthesia more prevalent than originally thought

Red. Totally.

Um, black for me.

This is not surprising to me - I would never call myself a synesthete, but I could do well on a test like this. "A" is always red for me, as is 5; 9 is always green. I think most of us have associations like that.

That looks like a Poisson distribution with no discernible signal in the synaesthete region to me. What's the statistical significance of the data? Why would a true synaesthete be unable to achieve a perfect score? Presumably you cannot misreport what color you're actually seeing.

Is color-word synesthesia more prevalent than the other types, say, taste-shape? And do they bear any relation to one another (even though they are different senses?)

I don't know about anyone else, but 5 is always orange and reminds me of carrots.
Now wether this is a true case of synesthesia or simply random synaptic contacts I do not know. Is it possible that there is no difference between these two options?
Perhaps a certain amount of "synesthesia" is absolutely neccesary for normal human experience of the world. This is evident in the huge amount of metaphors that combine seemingly unrelated sensory experiences.
For example, how is it possible that a bright pair of plaid pants can be "loud"? So loud, in fact, that you could hear their pants coming down the street. This very common joke would not be funny if people did not "hear" colors to some extent.

Also just black for me.

I do have this weird thing though that I kind of do subconsciously: whenever I'm looking at something, I try to divide the dominant color "patches" into basic geometrical shapes using the least possible lines.

So for instance: I'm watching tv and there's a closeup on a person's face. The background is all one color. I then draw lines in my mind to create rectangles (or triangles depending on the shape of the area) within that background, while trying to determine which set of lines are the shortest.

I've never known anyone else who does it and I regularly catch myself doing it without realizing it.

BLUE Monday???? Not likely! I speak three languages, and "blue" does not have the same word connotation at all. In fact, "blau" in German means either drunk or stoned which is usually associated with a weekend, or "blau machen" is to play hooky from work, the opposite of blue Monday which people associate with having to go back to work.

In French the word "bleu" used in conjunction with "bifteck" means VERY RARE steak. The color also connotes a greenhorn. "Sacre bleu" which is a term of swearing is a whole 'nother ballgame. I don't recall it ever being used in conjunction with Monday or with mood.

So, have these researchers tested subjects in other cultures or other languages?

Why was the threshold set at 19 and not, say, 20 or 25?

I took the trouble to record the colors I associated with letters, numbers and some sounds a few years ago. Looking back at them, my associations have not changed. I wonder how I would score on this experiment.

For those of you who are chiming in with your own associations and suggesting that "I think most of us have associations like that." I'd just like to speak up as a data point. I have NO such associations... there is no word I can think of that I associate with a color except through its meaning ("carrot" makes me think of orange, but that's different). Nor do I have such associations with any other senses. So no, it doesn't work that way with EVERYONE.

I'd also like to echo Xerxes' observation: the graph provided appears to show evidence that there's a perfectly normal (well, Poisson) distribution here, and nothing special about the synesthesites except that they're at one end of that distribution.

roseindigo, I think you're missing the point. Synesthetes do not necessarily associate Monday with blue. Some might associate Monday with pink. Others might associate it with green. Others might associate it with the smell of burnt toast. There's not necessarily consistency from person to person, instead, people with synesthesia experience consistency across time. (Monday always smells like burnt toast to you, whether I ask you today, or next week, or next year.) Additionally, someone who's synesthetic would have more than just an association for Monday. If Monday's blue, maybe Tuesday is indigo, Wednesday is chartreuse, and Thursday is lilac. Also, maybe the number 5 is orange, and the number 2 is turquoise. So I don't think you're seeing a cultural bias.

Uh, Michael, I said "most." I may well be wrong, and the number of people with such associations may be "less than most," since I have not gathered statistically sginificant data points. But I never said it was "everyone." Generally scientists don't say "everyone" unless they have really really good data to cover their behind. ;) There are too many people over there on the left of the graph with no consistency at all in their associations - at least, those associations tested in this study. Incidentally, Michael, I don't associate words with colors either - it's strictly numbers (1-20) and letters.

As for that maligned graph, doesn't it simply show how this new sample set maps onto the score range from previous studies of known synesthetes? It's not supposed to be determining a meaningful cutoff for synesthesia, it's merely showing how many people in a large sample meet some predefined cutoff. The surprise here is that more people fall above the cutoff than expected; and also, that it is a curve - indicating signficant numbers of people, like myself, do have some consistency of associations, though not rising to the established definition of synesthesia.

No color association with the word as a whole, but the individual letters certainly have associated colors for me:

M = red
O = gold/orange (but if I think about the "uh" *sound* that it stands for in this word, it becomes sort of blackish!)
N = blue
D = green
A = blue
Y = gold

I'm a linguist, and I have phonetic symbol-color associations, which I suppose can't be all that common. I'm also partly red-green colorblind, which puts sort of an interesting spin on things.

I have always described certain tastes as "green". And it has no reference to the actual colour of the food. Celery is not "green", nor is lettuce. Some chiles are, as is some rhubarb.

Some commercial soft drinks taste exactly to me like the taste I attribute to Mr. Clean (although I have never tasted this; it comes from the smell.)

And certain shades of red/orange/yellow have sharp edges and corners.

I don't think I have any crossover between words and the 5 senses.

I also do not experience colored words/numbers or any other associations like that. I had heard of synesthesia before, but I assumed it was just a few people who had something wired completely differently than the rest of us. Now I am wondering if, in fact, most people have some such associations.
This is not necessarily related but, during a class discussion once, we found that most of the people in the class had some sort of visualization of time or calendars (for instance, maybe they think of a big rotating circle with the months written on it, with different colors for different seasons, or something like that). I have absolutely no visualization of time passing other than the fact that I could visualize calendars I have actually seen in real life.

When I was a child, I had consistent color associations for numbers, letters, geometric shapes (with less consistency), and perhaps certain written words, though these most likely derived from the individual letter associations. I don't think it was ever literally a sensory perception, just that color was a subtle part of my brain's system for mapping these concepts. I'm rarely consciously aware of this color system anymore, though I can still call up the identical colors for these things today.

Monday is red, probably because of the "M" and "n."
"a" is yellow, "e" and "y" are shades of yellow-green. "d" and "o" don't have as strong color values, so they're black or blue.

I'd really be interested in comparing these associations with flashcards and alphabet books from my childhood.

Re: Lisa (comment 15)

I have exactly those number/date visualizations. Most people I've talked to don't have a clue what I'm talking about when I mention it, but my mom and sister understand completely. We independently sketched our yearly and weekly calendars in a bar one night and they were strikingly similar (and bore no resemblance to a typical "calendar"). Everyone sat and stared at us like we were nuts. I believe such patterns are a form of synesthesia, but probably not the most extreme manifestation.

bioephemera (et seq.), the point is precisely that most people don't have such stable associations. As self-described, you're a classic "mild" synaesthete, of the same grapheme/color type as Vladmir Nabokov. (A stronger form wouldn't just think of the colors, but would actually see them.)

I find myself wondering about the frequency of particular color/grapheme connections among a population....

BTW, I do have a bit of crossover from music to visual imagery, which I find more distracting than entertaining. (Muzak is a real PITA.)
Thus I'm thankful I don't have the grapheme/color stuff, as I value my fast reading speed.

This does raise the interesting point of how one would reliably differentiate a synaesthete from a a-synaesthete. Does anyone have their DSM-IV handy and want to see if it is listed there and what the associated criteria there are?

@roseindigo I do agree that testing bilingual and multilingual synaesthetes would be very interesting. How would their associations hold up under Whorfian scrutiny.

Take a person who is non-preferentially bilingual in both English and Russian.

The Russian Language makes an obligatory distinction between lighter blues ("goluboy") and darker blues ("siniy"). In contrast English does not. (doi:10.1073/pnas.0701644104)

Would they report Monday's as Blue in English and either "goluboy" or "siniy" in Russian? Or would they fail to report a synaesthesia when placed in a Russian context.

I have a feeling that bilingual people would be partially immunised against developing synaesthesia primarily due to conflicts like this. Maybe I'll do my phd on it....

Of all the lectures that have synesthesia as the subject, this one is the best - http://www.bbc.co.uk/radio4/reith2003/ram/lecture4.ram

the main page where the other lectures given by the same person (V.S.Ramachandran) is in - http://www.bbc.co.uk/radio4/reith2003/lectures.shtml

V.S.Ramachandran is the neuroscientist at the frontline. His lectures are the most lucid. He breaks the conventional meaning of synesthesia and you'll be shocked to experience some of the revelations he's about to offer. Try them.

re Nick, David Harmon:

I'm only a "mild" synesthete as well, but I don't get colors from the letters of the word--I get gender.

M=masculine
O=masculine
N=feminine/but not overly so
D=neuter/trending to male
A=masculine
Y=masculine

BUT

...in combination, letters' genders can morph somewhat, in much the way sodium chloride has different properties than sodium or chlorine.

So, even though -MO- has a masculine "polarity" in isolation (as one might expect from its components), -AY- tends to have a "feminine" polarity for me--and that changes the "conformation" (to overstretch the analogy somewhat) of the overall word into a mosaic of impressions. For some words, the "polarities" of letter groups dominate: -IRI- for me always tilts a word in the feminine direction, but initial R tends to "masculinize" a word's mosaic somewhat.

For what it's worth, I began reading at 2 and I'm just a wee bit gender-bent for a man (my folks were in the 60s, you know, so I got dolls to play with as well as boy toys), so I could imagine all that might be part of why I get gender associations with letters and numbers... but I could certainly believe there's no connection, as well.

I do have a highly developed analogical sense and a freaky memory, so when I saw MONDAY I first thought of blue because I recalled one of the illustrations from the New Order album Substance, including "Blue Monday". So could the letter/number/gender thing be just some deeper, unconscious version of stuff like that, even in part?

-pr

Adi, regarding your interesting commentary, and especially this one: "I have a feeling that bilingual people would be partially immunised against developing synaesthesia primarily due to conflicts like this."

That's it exactly. I can guarantee that I have not one iota of synaesthesia precisely for this reason.

Interesting discussion,
Reminds me a few years back at lunch one of my colleagues goes all surprised
"WHAT? You see all the letters with the same color?"
he went on to tell us he sees every letter in a different color, every word in a different color and he always though everyone was like that and never bothered to ask other people about it.
At first we thought he was joking or playing some silly trick (but it was easy to confirm he was not) then after some googling it turned out he had a mild case of synaesthesia and had no idea about it.

He is tri-lingual for whatever thats worth.

Maybe I'm missing something, but isn't this sample biased towards people who (correctly or incorrectly) think they have some sort of synesthesia or *some* kind of unusual association? Isn't that graph showing only the people who indicated that they an association and were tested further?

Am I interpreting it wrong or is this how synesthesia studies are usually done?

Ah, I see, the 380 subjects who had no associations at all must have been factored in lator to get 1%, as the total on the graphs add up to between 2-3%. Still, I second the curiosity as to why 19 questions is the cut-off point.

You mean it's not just me?? :) I have also primarily felt gender associations when thinking about letters, numbers, colors, days of the week, and even entire words for as long as I can remember, but I also add age and physical appearance to it. It's like each one has a whole personality (I can even tell you what some of their hobbies are!) In fact, personalities can even correpsond such that a number and a color will have the same one--for instance 6 and green. I don't always think 'green' when I see 6, but if I think about both color and number, they end up being roughly the same 'person'.

When I combine single digits into longer strings of numbers, it ends up being like a representation of complicated interpersonal relationships (my bank account is quite the interesting group and they can never really seem to make friends with each other.) For instance, 3 is a little boy, 6 is a quiet middle-aged woman, and 9 is similar to Snow White's wicked step mother--tall, thin, cold self-absorbed personality and black hair. Pairing numbers, like 27, gives images of both a single entity and a dual entity--a romantic couple or a family group, depending on the numbers.

Relation is due, in part, to how the numbers are related mathmatically: 2 and 3 are sister and brother, 5 (2+3) is their father, six (2*3) is their mother, 9 (3 squared) is an elder aunt, etc. However, parentage does not equal pairing, and the relationships are not entirely consistent: 1 and 5 have a thing for each other, 6 has a crush on 8, who is far too cool to notice, 7 is the total geeky recluse brother of 6 who would get on famously with 11 if they could ever meet, and 9 (wicked queen) is married to 10, the portly king of numbers. (Keep in mind I've been associating these personalities since early childhood so they tend to be a tad fairytale-ish.) And of course, these aren't just limited to the numbers 1-10. Oh no, it goes on and on--and that's just numbers...I've got this going on for colors, days, letters, and words too! Every every mathematical equation tells a complex story to me about the numbers' & letters' latest adventures. I guess maybe this just helped me learn math when I was younger. Who knows! However, I can never separate this association in my mind, no matter how hard I try. It's impossible.

@roseindigo
I also have not hint of synaesthesia, however I only speak English.

My comments about bi/multi-linguals would only hold true for those who are native speakers in both languages. i.e. those who learned both languages concurrently and have no preference for either.

What makes this discussion interesting is the fact that we are using language to describe concepts that may vary significantly between linguistic communities. That is why I feel the need to put all 'colours' in inverted commas because 'blue' may not exist in every language in the same sense that it exists in English.

As for gender associations, I do wonder if people who speak languages that make obligatory gender distinctions would be less likely to class these associations as actual synaesthesia? I can't really comment because English is a relatively ungendered language.

Zef:

I'm not the only one!! My numbers also have relationships, but I suspect that this was more something I created in my mind in order to manage my times-tables better when I was younger. 6 is married to 7, 6 is a beautiful woman and 7...well, he got lucky. They have a child, 42. 2 and 3 are good friends and sometimes like to visit 5 (2+3). I never really liked 9 for some reason. It goes on. I can't say I went so far as to give them hobbies, and many of their relationships are inconsistant. To this day, I use the paring when I am adding in my head - and I will always split my 5's into 2 and 3.

Interesting.. but I wouldn't say it is Synesthesia!

Hmmm, interesting point adi: "I do wonder if people who speak languages that make obligatory gender distinctions would be less likely to class these associations as actual synaesthesia?"

For instance, in German a girl is neuter (das Maedchen), and a turnip is feminine (die Ruebe), and it's all mixed up with no real rhyme or reason. Yes, I would like to have an answer to your above question. The only time I have a gender preference that I can think of is with cats and dogs. Cats are always feminine to me, dogs are always masculine, no matter what their gender actually is.

Adi, your question of: " I do wonder if people who speak languages that make obligatory gender distinctions would be less likely to class these associations as actual synaesthesia?"

Yes, well in German the obligatory gender is all mixed up with no seeming rhyme or reason (since there are three), and girl is neuter (das Maedchen) and a turnip is feminine (die Ruebe) and rain is masculing (der Regen). So I do wonder about synaesthesia in other language groups.

The only time I have a specific gender association, it seems, is with cats and dogs. I always think of cats as feminine and dogs as masculine, no matter what their actual gender is----until I get to know them. :-)

In fact, I think of letters and numbers in the same way as I think of notes, just symbols with no specific color or gender, until it is combined with others to make a coherent whole, and that WHOLE does have meaning to me. Frankly, I can't even conceive of some of the phenomena that people are describing here---and I'm an artist to boot.

I associate genders, personalities, and things with numbers, letters, colours, and objects. And I associate sounds and feelings with colours and different sensations. I didn't find out that this was synaesthesia until a while ago, when I stumbled across the type.

So Cat, that is a form of synaesthesia. :D

Just because 1 percent of the population score as high as real synaesthetes on this test does not mean that the prevalence of synaesthesia is that high. The distribution could easily be explained if the test were a measure of association memory.

Whoever asked about the types of synaesthesia: I believe grapheme (letter/number) -> color is the most common.

Also, one can distinguish between actual synaesthetes (those who actually have the induced sensation) and those who only have a memory trace by doing tests where there is a very clear performance benefit or defecit for synaesthetes. A modified stroop task, for the grapheme -> color synaesthetes works rather nicely. Rama's work describes a number of different tests.

I certainly felt associations between letters, numbers, days of the week, and some first names with colors when I was younger. However, I can't say that it was ever very compelling. I can only really remember "getting" the colors when I was thinking about the matter, and I can't vouch for the associations being consistent over time. It certainly made a sort of sense to think of these things as being colored, but I can't say I truly saw the colors, and I don't know that I can even really "get" them now that I am older.

Whether that is enough to qualify as "mild" synesthesia, I do not know, but I have always been puzzled by the claims about "strong" synesthetes actually seeing synesthetic colors. It is not that I disbelieve, but I am not sure what claim is being made. Where is it that the colors appear? Suppose, for example, someone sees the number 5 as red. Where is the red?

I have heard of experiments where, allegedly, a synesthete can pick out a number or other symbol among distractors faster than "normals" can, because it is a different color to them and thus "pops out" (I can't place the citation at the moment, but it might well have been Ramachandran). This suggests that the ink of the numeral 5 might actually look red rather than black to the synesthete, or perhaps it might be red-tinged black, or perhaps the black numeral is fringed with red. However, if the color is actually associated with the number rather than the numeral (as it would have been for me) where would the red appear if the strong synesthete heard the word "five" being spoken? (Maybe there are some synesthetes who respond to written numerals but not spoken or otherwise evoked number names, but surely this can't be the case for, say, day of the week synesthetes. Surely if Monday is yellow to you, it is not just the printed word MONDAY that is yellow, but the very idea of Monday.)

One possibility, I suppose, might be that the whole visual environment becomes temporarily suffused with the color, taking on a color cast, as it were; or might it perhaps be just that a mental image of the color is evoked, with no particular spatial location (as is common with mental images). That is certainly how it was for me, but then the insistence that strong synesthetes actually see their colors becomes puzzling (the pop-out experiments are hard to understand on either of these interpretations). I suppose it might be the case that for strong synesthetes the color image appears much more consistently, insistently, compellingly, and perhaps more vividly than it ever did for me, but to call that actual seeing would be misleading at best.

I say this as a genuine question, not as an expression of skepticism about synesthesia (though I do have some doubts about the pop-out phenomenon). Where, for strong synesthetes, do the synesthetic colors appear? I realize the answer might be different from one synesthete to the next, but in each case I think it remains a very relevant question, and one that I have never seen properly addressed in what I have read about the subject (admittedly only a quite small sample of the literature). Does anyone (synesthete or student of synesthesia) have any answers?

[If anyone wants to respond privately, you can find my email, in spamproofed form, on my website http://www.imagery-imagination.com/]

Glad there is more and more research on synesthesia. for more articles, programs, visit the "Blue Cats synesthesia Resource Center":
www.bluecats.info

Nigel:

Reports vary on the "location" of the synaesthetic experience. For colors, some individuals report that the color floats above the word/letter (i.e. in a different plane than the stimulus), some report that the color is actually in the plane with the word/letter (I'm guessing this might be like a red-tinged black or some sort of bistable percept like the changing colors on currency), and some report that it appears in the "mind's eye".

Also, one study involved a synaesthete who didn't need the actual inducer stimulus to get the color, but I have a feeling that the researchers may be glossing over some other possible explanations, such as interference at the level of verbal report, instead of actual synaesthetic experience. [http://www.nature.com/nature/journal/v406/n6794/full/406365a0.html]

I read a book on synesthesia years ago, and for about five minutes had an inkling that I might have a very limited bit of the tendency. My clue was a strong association between some numbers and colors. One was yellow, two blue, three red, four purple, five orange, six green, seven dark red, and eight black. Then I realized I was just thinking of billiard balls.

Hao:

So are you saying that synesthetes (or at least the ones you are talking about) only get the color response to the written numeral, word or whatever; that they will not experience the color if they hear a number mentioned (or just think about it)? At any rate, your answer only seems to apply to the former case. I am not questioning the fact that synesthetes may have told you this, but I am not convinced that it can cover the full range of relevant synesthetic experience (even for just the people in question).

At any rate, I find the idea that color synesthetes might get the colors only in response to written stimuli surprising (And I would start to ask questions like "Does the font matter?" or "Does handwriting evokes the same colors, or an equally strong response, as print?") Certainly the idea of synesthetic colors being evoked by written numerals only does not at all jibe with my memories of the (admittedly very mild) synesthesia that I experienced when younger (not just as a child, I might add, but certainly well into my twenties, and occasionally, faintly even today). I do not recall ever spontaneously experiencing any colors when reading numerals or whatever on a page. I would probably have been focused too much on the math problem or whatever else they expressed, to be aware of any synesthetic colors. However, when idly thinking about numbers (and names, and days of the week), it definitely seemed to me that different ones were (or went with) different colors. I had never heard of synesthesia at the time, but the fact that numbers were colored did seem to me both an odd and an interesting phenomenon, and I think I initially assumed that they would be colored (and colored the same way) for everyone. I can remember not just thinking about this, but talking to friends about it (some were dismissive, some came up with different colors to mine). Perhaps it is worth adding that the colors were not generic ones - it was certainly not just verbal association with color names - but very distinct hues and shades that were often very hard to capture satisfactorily with a verbal description.

I remain puzzled that so little systematic attention seems to have been paid to the detailed phenomenology of synesthesia, especially given that, as something fundamentally subjective, its phenomenology is its very essence. Hopefully we are now past the point where critical questioning about the phenomenology of synesthesia will get confused with raising doubts about its reality.

Perhaps, Pat Duffy has the answer, or at least the answer for her, as she is apparently a strong (and articulate) synesthete. [Unfortunately I can't currently access the Nature article that Hao points to.]

I have a degree of absolute ('perfect') pitch perception--that is, I can identify the names of played music notes upon hearing them, and can produce them at request...and, for example, if a piece was being played or sung a bit out of tune with the absolute standard but the intervals were consistent (so that the piece would sound in tune to other people, but the whole thing would be a little higher or lower) I would probably notice; it would feel a little funny. Many people have this more strongly than I do, but my question is: is perfect pitch considered a form of synaesthesia? I don't consciously see colors associated with each note, but there is some intrinsic quality that makes, say, a D sound different than an F# on any instrument that I can notice, although my perception isn't perfectly clear all the time. Does this make me mildly synaesthetic, or is this different?

Daniel,

I would say you don't have synaesthesia, as the different sounds aren't associated with taste, color, or any other sense. You just have the gift of perfect pitch.

I can't believe it!!!!!!!!!!!!!!!! You can't imagine the relief I feel reading this site. I always thought I was crazy, but to find out this is a shared condition. I don't feel along. I want to know more.
My name is Lauretta, and every sense I can remember my world is vivid with lights,color, and sound (like auros during a migrain. My colors have taste, letters with color, and the most outstanding blue has an emotion. I EXPERIENCE blue with absolute blss. Certain smells have colors and I can remember some events with great accuracy. It is as if a movie is being replayed in my head. It help also to remember a person by the color of their name or aura attached to them. I no this sounds silly, but true.

Looking at the comments, it seems I'm in the minority -

"I have NO such associations... there is no word I can think of that I associate with a color except through its meaning ("carrot" makes me think of orange, but that's different). Nor do I have such associations with any other senses."

Me too. Words are whatever color they're written. I think some people have a predisposition to make permanent, strong subconscious connections like this, but I've always felt it's more a consequence of signal processing than anything else. "Synesthesia" might be an interesting phenomenon from a developmental standpoint, but I don't think it's necessarily what it's made out to be.

I don't have any word-colour associations. But I do often taste sounds, and emotions and symbols are represented in my mind as sounds or tones.

The taste/sound thing has the interesting side effects that certain music is really great when I'm hungry, and I (most emphatically) do not want to listen to music at all when I'm feeling dizzy or nauseous.

I enjoy reading articles about synesthesia, because for years I thought I was the only one who had weird associations with letters and numbers and seasons.
But anyway, Monday for me is blue, but because my association of the actual letters combining the words.
M is blue and cold and dominant. It casts the color and temperature on the whole word.

Actually synesthesia, since I was aware of it helped me a lot with remembering things like names, addresses and numbers.
Even now mentally - I visualize the phone number and consciously note what colors and temperatures correspond with numbers, and file it away in my head as "ok, its a little blue and a lot of purple, and mostly cold"
Sounds odd, but it works. It may not let me memorize the exact number at first, but gives me enough clues to match the "legend" with the actual numbers.

Maybe it's a long way of doing things, but it's better than not remembering anything at all!

At some point I realize that each person's name has a texture to me as well, and it doesn't vary from person to person. I told my friends, they are trying to unsuccessfully to decipher why their name is a particular texture, thinking that it's my way of subconsciously describing their character. Not the case at all, because two different people with the same name would have two different textures. But they don't.

I have somthing somewhat different every thing has a "feel" to it not tactile, but somthing i cannot describe it is somthing like a common language that the diffrent parts of my brain uses thou the actual uasge at that level has a color like the term color is used in quantum electodynamics. Each season or day of the week has somthing like its own feel every word does also thou I'm not allways aware of it. It is not always helpful sometimes it is like trying to distinguish various close shades of grey on paper that affect the hue significantly when tilted at a slight angle.

Eugene, I understand what you mean. Certain feelings cause tactile perceptions for me, too. Being very very afraid (panic, or terror, even) have always made me feel like I was holding a ball with spikes, which I couldn't let go of (since I wasn't actually holding it). I remember when I was very young (like maybe 3 or 4) and being terrified when my parents would go out, and I would get this sensation and get even more scared because it would just be too much for my little brain. Even now, remembering the texture makes me scared, luckily I haven't been that scared many times in my life. Great sadness, similarly, is a punch in the stomach, or maybe the feeling of grabbing it and tightening.
A lot of objects also have inherent personalities, so that I would (and, sometimes still do) consider the moon or specific trees my good friends, or think of pears as very sexy.
The distinction, though, between synesthesia, an active imagination or a simple relation of ideas, etc., is that, if you did a brain scan, you would find that for the synesthete who sees color when hearing music, the part of the brain responsible for vision is actually activated. The other main distinction is that these connections do not change, so that a person with synesthesia that saw tuesday as red when he or she was 5 years old will still do so at 80.
For more information I would recommend the BBC's documentary "Derek tastes like earwax".
Adi and roseindigo: I come from a spanish speaking country and, along with spanish and english, can also speak french and some catalan, (three languages which give specific genders to things) and have many friends who can speak as many (or more languages), a lot of them do assign gender, color, or whatever to numbers, letters, or words or objects, and it has nothing to do with the language. It depends on the type of synesthesia (be it mild or not) that you have, as well as your own personal connections.
For people with grapheme based synesthesia, written letters and numbers (or maybe written words) will have certain characteristics. It might be that the letters of the alphabet they're used to don't cause any sensation, but then they come across chinese characters and these DO have a gender or a color (for example).
On the other hand, people with auditory based synesthesia will simply taste/see/feel/whatever a word upon hearing it. For some people this will only happen with words they're familiar with (once again, watch "derek tastes like earwax" for more information), while, for others, it's the union of sounds and not the actual word that causes the sensation, so that hearing a word in a foreign language will cause a synesthetic reaction even if they don't know what it means.
Like someone before me already said, the actual meaning or common social connotation given to certain colors or concepts have absolutely nothing to do with the synesthetic experience. So just because in Germany blue is associated with the weekend doesn't mean that a german synesthete won't see (or feel) maybe Wednesday as blue. The causes for the connections that synesthetes make are basically the biggest mystery of all, since they vary from person to person.

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