Is tasting something you see a form of synesthesia?

Question

Synesthesia is often stated as "a confusion of the senses" and some of the more common forms include "seeing sounds" or associating letters or numbers with colors. There is also a very rare form of synesthesia called lexical-gustatory synesthesia where one "tastes words."

One thing I've occasionally experienced is that I'll see something and then involuntarily will taste it in my mouth. It's almost always things that are not pleasant, like carpet or copper (things I've tasted when I was a child, I don't regularly eat these things!), and more often when seeing them in large concentrations (e.g. a particularly shaggy carpet, lots of bare copper). Like tasting food, I seem to become acclimated to it pretty quickly.

The closest thing I've heard from other people is they'll say that food "looks so good I can taste it" or something like that. However, I usually hear this for food that also smells very good and as I understand this tasting is because smell and taste are linked (which is normal, not synesthesia). However, I experience this tasting with things that don't have any noticeable smell.

I'm not looking for a diagnosis, but I'd like to know if tasting something you see as I have experienced is something that could possibly fall under the category of synesthesia (or if there is a more mundane explanation).

Answer 1

After a fair amount of research, I came across Noam Sagiv, PhD, a professor at the Centre for Cognition and Neuroimaging who has done research into synesthesia, including visual-gustatory synesthesia (the proper term for seeing-tasting synesthesia). I contacted him about this and he said the following (reproduced with permission):

I can understand your frustration with finding information about this. As you probably know already from trying to look up information on synaesthesia, there is a lot more research on coloured letters and numbers than anything else.

There are a few types of synaesthesia where taste is the inducer (e.g., coloured taste) and a few that involve taste as the synaesthetic experience: For example, musical notes/intervals > taste, or lexical > gustatory that you mentioned already.

In our experience there are also two other variants; there are no published papers yet that I am aware of but we recently accepted an invitation to write one.

1) We tentatively labelled it mirror-taste synaesthesia - this is where you see someone else eating something (with no smell - e.g., on TV) and experience a flavour experience that mirrors the other person's - i.e., similar principle to "mirror touch" synaesthesia, where you see someone being touched, and feel the same experience on your own body. The "social" aspect here is critical - it's not enough to see the food, you need to see another person eating it. My conference presentations covered this one - particularly a brain imaging study we conducted, where we found that basically, we all do something similar, even if only a minority of individuals actually experience it: What we found is very simple, that videos of people eating activate not only the visual cortex (which is what everyone expects) but also the gustatory cortex, despite the absence of direct stimulation of the sense of taste.

2) The other type of gustatory-visual synaesthesia we would like to start exploring soon, is the more direct type you describe. You see something that you've tasted before, and experience the taste involuntarily/automatically and vividly. We have a couple of anecdotal cases but haven't started the formal survey. I expect this to be more common with foods than with non-edible things, but the fact that you get this for some early experiences is consistent with findings from gustatory lexical synaesthesia (where the synaesthetic taste "repertoire" includes things you've eaten as a child, even if you haven't had those for 30 years, and doesn't include things you eat often now, but haven't tried as a child; these things probably consolidate in the first decade of life, probably first half).

We often find we learn new things from synaesthetes and enquiries like yours. I'd be grateful if you did participate in our forthcoming survey, and/or other studies in the lab if you are in the area (West London, UK).

So the short answer from a leading expert in the field is: this area has not been extensively researched, but tasting something you see does indeed seem to be a form of synesthesia, possibly including the situation that I described in the question above.

Dr. Sagiv has also extended the invitation to participate in research on synesthesia to everyone here on CogSci Stack Exchange, so feel free to contact him to discuss any synaesthetic experiences, volunteer to participate in a survey, and/or go to his lab in West London.

Answer 2

You ask "if there is a more mundane explanation" and note that you're "not looking for a diagnosis." As you'd expect of course, it seems sensible to conclude that indeed no definitive judgement can be made about the cause of your experiences without some sort of professional assessment. And there are methods available to attempt to make such a determination.¹ My cursory research indicates that these are in the process of development, that there is nothing "official," but that some are described as "reliable." Whether there are any applicable to sight-to-taste sensations, I can't say.

As you note, sight-to-taste synesthesia typically involves things like letters, words, numbers, colors, or shapes. I did find a few examples of perceptions similar to yours. One relates to a man who experienced synesthetic taste sensations of "synthetic inedibles (wax candles, for example)."² Another is a reference to the idea that some synesthetes "may connect the sense of sight to taste so that every time they see a sailboat they will taste a donut'."³ Finally, there is another mere supposition that "llamas [may] look like sweet and sour sauce."⁴ These examples seem to confirm an observation that "[t]here are a lot of synesthete stories around the Internet, but many of them are lost within blog comments, outdated forums or hard-to-read Tumblr threads."⁵

"A more mundane explanation," in this case related to more common forms of "blended senses," is found in the theory that "people who have Synesthesia just retain color memories from childhood. An example would be colorful alphabetical or numerical magnets that the child had played with. This theory, however, does not explain all aspects of the condition."⁶ It seems impossible, based on the information available, to even speculate about the likelihood that your sensations result from childhood experiences, although you do note that you may have " tasted [cooper and carpet] when [you were] a child."

You may be interested in a recent study of so-called " learned synesthesia," examining "whether traits typically regarded as markers of synesthesia can be acquired by simply reading in color."⁷

Is there any history of synesthesia in your family? "It is believed that one gene which is responsible for causing Synesthesia gets passed from one generation to the next by the X chromosome, as a Dominant trait (Smilek, 2005). This could explain why Synesthesia runs in families."⁸

Finally, you may be familiar with the work of Richard E. Cytowic, a medical doctor and an Associate Professor of Neurology at George Washington University, and a leading authority on synesthesia. He is the author of The Man Who Tasted Shapes, and was featured a few years ago on the American television program "60 Minutes." He may be interested in your experiences. You might want to contact him.

¹ "There are several screening techniques that are used in diagnosing and confirming Synesthesia. … These are called pop-out, segregation, cross-modality imagery, and the Stroop test." — from Synesthesia: The Medical Condition of Associating Letters and Numbers With Certain Colors (2007), by Jennifer Rossman, citing Crane, Carol A. (2006). Synesthesia. A neuropsychological and familial study of developmental synesthesia. Dissertation Abstracts International, 66(8-B), 4477,

² A Summary of Current Ideas on Synesthesia (2007?), by Megan Davis, for an undergraduate seminar in Cognitive Psychology at Goucher College.

³ A FAQ about synesthesia on a blog published on wikispaces.com.

⁴ A document about synesthesia published on everything2.com

⁵ Maureen Seaberg’s Synesthesia Story (Video), a blog post on blendedsenses.com

⁶ Rossman, citing Ramachandran, Vilayanur S. & Hubbard, Edward M. (2005). Hearing colors, tasting shapes. Scientific American Mind,16, 16-23.

⁷ Pseudo-Synesthesia through Reading Books with Colored Letters (2012), by Olympia Colizoli, Jaap M. J. Murre, and Romke Rouw.

⁸ Rossman, citing Smilek, Daniel, & Dixon, Mike J. (2005) Synesthesia: Discordant male monozygotic twins. Neurocase,11(5), 363-370.