DNA Results: Positive for Tetrachromacy
This blogger is not just a synesthete but has a fourth cone class for color
Posted Oct 14, 2013
I put myself out there recently and suggested I might have tetrachromacy or the presence of a fourth cone class for color perception. I also suggested that there could be a link between synesthesia and the trait. I participated in a DNA study and was awaiting the results as I wrote the post.
I was pretty confident that something was "up" with my color perception. I remember on a trip to Ireland when someone pointed out the "40 shades of green" the verdant nation is known for, it seemed such a gross understatement to me! There must be thousands, I thought. Also, you really don't want to go clothing shopping with me. I will search and search and search some more until hues match exactly among pieces. When sales people assure me the pieces do match, I can only look at them sympathetically and continue searching. I'm sure the designer thought they matched—but dye grabs differently on the wool of a sweater as opposed to the denim of jeans. And it may match to most of you, but yikes, I see the difference.
Well, the results are in! Dr. Jay Neitz of the Neitz Lab in Seattle, wrote me an email last week. "I just wanted to let you know that you do have the genetic basis for 4 types of cone photoreceptors."
I say I "seem to experience tetrachromacy," because though I have the genes for it, and a lot of the experiences of proven tetrachromats, the jury is still out on how "functional" a tetrachromat I am. Twelve percent of women are believed to have the genes of tetrachromacy, but it is not expressed in all of us. I will have to be tested further -- but researchers are still working on foolproof diagnostics for the expression of this.
It seems to me that many more women synesthetes are likely having similar experiences to my own. When I posted the previous piece about this on social media, dozens of "synnies" responded that they, too, see subtleties in color more than "normal" people and tend to recall color from memory much better, too.
A researcher recently wrote me through Psychology Today that as a synesthete herself she is interested in designing a study to look into the connections between synesthesia and tetrachromacy. I will share her information when more becomes available and wait to see if a link is proven.