Any household with young children likely features a set of colorful fridge magnets representing all the letters of the alphabet. They are a puzzle to me, because having only one copy of each letter gives you a very limited range of what might be spelt, and a bane to any parent who has had to reach under the fridge to hunt for lost letters. But these colorful artifacts of childhood may hold a special place in the mind of synesthetes, those individuals whose brains are wired to trigger perceptions of color whenever they see a letter; the fridge magnets may be the source influencing which specific color they perceive for each letter.
Now, the presence of fridge magnets in a household is not likely to create the particular cross-wiring of sensory areas of the brain that leads to the synesthetic perception of color when letters (or numbers, all called “graphemes” in psychological parlance) are perceived. But the presence of fridge magnets that definitely and concretely pair each letter with a color could conceivably influence which color, of all the colors of the rainbow, is tied to each letter. And thus a scientific study was born, in which 11 synesthetes were asked to use hue sliders until the color on the computer screen matched the color they saw in their head for each letter of the alphabet. These colors were then compared to fridge magnets — which brand of fridge magnet doesn’t seem to matter, as makers all seem to have settled on a fairly consistent rainbow pattern: A red, B orange, C yellow, D green, E blue, F purple, and the rainbow repeating with the alphabet. (This makes Y red and Z orange, the two only colors that appear more than 4 times).
And here is where a very intriguing study hits a road block with me. Although the claim that these 11 participants are synesthetes has the weight of multiple statistical analyses behind them – showing that they are very consistent in picking the same colors for each letter, across sessions that are often several years apart – the connection to the fridge magnets is not statistical at all. Instead, all we get is a picture, showing the colors identified for each letter of the alphabet by each synesthete.
Oh, it’s a very pretty picture, and it tells a reasonably compelling story: Look at all those red A’s, and orange H’s. But…what about that string of white O’s? And does that pattern seem to get a bit messy to the far right, where those last few synesthetes seem to diverge more frequently from the fridge magnets?
Presenting their results in this visual form is understandable, to a certain extent, because the synesthetes’ colors were chosen with a color picker that could create subtle differences in shade: not all oranges are the exact same orange, but mathematically determining closeness to the precise hue of the magnets would be a logistical nightmare. But I found myself staring at that picture, trying to look for patterns and exceptions and in the end only partially convinced that the synesthetes matched the magnets in a sufficiently impressive manner.
To get a more numerical feel for how well synesthetes matched those magnets, I set myself up as a disinterested coder – not blind to the expectations of the researchers, but not particularly tied to them either. I cycled myself through each synesthete’s alphabet, asking myself about the colors they had chosen: Is that red? Is that orange? Is that yellow? If I would look at that color and give it the same name as the fridge magnet, the synesthete scored a 1; if not, they scored a 0. (Yes, this is very subjective, which is why it would ideally be done by multiple coders to get a sense of consistency; however, there is also some evidence that groupings of hues within one category name of color can be consistent within a language, because we are unlikely to look at something pinkish and call it blue).
I turned to some simple probability to decide what I would compare the synesthetes to. If a non-synesthete such as myself were to sit and guess which of the 7 colors of the rainbow goes with each of the 26 letters of the alphabet (in random order, so that following-the-rainbow pattern wouldn’t emerge) I would mathematically match the fridge magnets 1 time in 7, or 3.7 times total, or 14% match. (Yes, this is ignoring white and black, but then I’m not trying to get past a peer-review with my analysis). The synesthetes, on the other hand, ranged in match rates from 42% to 100%, with an average of 72% matches to the fridge magnets (and a standard deviation of 21%, for those of you who are statistics inclined). I plugged my numbers into a statistics calculator, to get an official estimate of whether the synesthetes scored better than the chance match of 14%, and it came back as highly significant (t(10) = 9.2, p < .0001, for the stats minded).
My numbers can also be put into their own picture, which tells a story just a compelling as the original, with the advantage of being clear even to the color-blind among us.
I admit I do wonder what notes were passed between the study’s authors and the scientists who reviewed their paper: whether this kind of analysis was asked for, and what rationale was given for its absence. The lack of formal analysis does not do anything for those of us who must still convince the “hard” scientists (chemistry, physics, and the like) that psychology is a science as well.
Fortunately, my own analysis allows me to be persuaded in favor of the study authors: The synesthetes’ perceived colors for each letter of the alphabet matches the classic fridge magnet toy remarkably well. Unless there is something inherently yellow about U that I am missing, that separately led both the synesthetes and the fridge magnet designers to make it yellow (and the follow-the-rainbow pattern to the fridge magnets make this unlikely), it seems that playing with those fridge magnets helped bias those child synesthete brains in the direction of a particular color for each letter of the alphabet.
On its own, this doesn’t tell us exactly how or why some people become synesthetes in the first place. But considering other evidence that many babies might be synesthetes, we can theorize that we are all born with some cross-wiring in our senses. For many, the senses separate through the process of synaptic pruning as our brains rid themselves of unneeded connections to become more efficient. In adult synesthetes, those connections have not be fully pruned away…and the connections that remain, matching each letter to one and only only color, may have been kept strong by something as simple as fridge magnets.
Witthoft, N., & Winawer, J. (2013). Learning, memory, and synesthesia. Psychological Science, 24 (3), 258-265 DOI: 10.1177/0956797612452573