Mirror Touch Synesthesia and the Genetics of Synesthesia
Imagine cold fingers creeping up someone’s calf. Now imagine that whenever you saw someone else being touched, you would feel the sensation on your own body. That is mirror-touch synesthesia.
Psychologists at UCL verified mirror-touch synesthesia and further showed its linked with heightened empathy in their report in Nature Neuroscience.
Synesthesia–literally “joined sensation”–is a phenomena that involves one sense being detected through a different sense, or ideas concepts triggering automatic sensory experiences. Mirror touch synesthetes observing someone touched the left side of their cheek, perceive it as a touch on their own left cheek (anatomical), or on their right cheek (mirrored).
Mirror synesthesia was verified in subjects through a sensory interference task. Subjects were touched on either the left, right, both, or neither cheek(s), while observing someone else simultaneously being touched in either the same or different locations. When the observer was being touched in incongruent manners, synestheses made higher rates of errors than controls. Also subjects responded slower on incongruent trials than congruent trials (which I don’t think would be expected if subjects were faking there responses).
Banissy (2007) Nature Neuroscience
Then, the scientists measured empathy quotient (EQ) in mirror-touch synesthetes (n = 10), nonsynesthetic control participants (n = 20) and grapheme-color synesthetic controls (n = 25). While nonsynesthetic controls, and grapheme-color synesthetic controls were not significantly different, mirror-touch synesthetes showed significantly higher scores on the emotional reactivity subscale and trended higher in the other two subscales.
Can we explain the mechanism for these differences in perception and empathy between mirror-touch synesthetes and the rest of us? As the authors of the study point out, electrophysiological studies in monkeys show mirror neurons that activate with sensation and with the perceptions of those same sensations in others. Similarly, fMRI studies of humans watching someone else experience a sensation or an emotion, show increased activity in brain regions associated with the equivalent sensation or emotion. An fMRI showed mirror-touch synesthetes experience hyperactivity in this mirror-touch network, which might also explain their stronger reactions to others emotions. On the other side of the spectrum may be autistic individuals with deficits in imitation and empathy. So like with autism, could genes predispose someone to be a mirror-synesthete?
Genetics of Synesthesia
Back in November the Eagleman group of Baylor College of Medicine, published a genetic linkage study (full text) of colored-sequence synaesthesia (CSS) where letters, numbers, weekdays, or months that trigger colour experience. Neuroimaging studies show increased activation of V4 (which processes color sensation) in these synesthetes, as shown in the figure below.
(A) In this model of synesthesia, neural populations coding for graphemes (right inferior temporal gyrus, light blue) ramify on those coding for colors (area V4, dark blue). As a result of these connections, activity triggered by a grapheme kindles V4 activity, and (B) synesthetes experience an automatic color association, an example of which is shown here. Tomson (2011) Brain Behavior and Research.
Its thought that this cross-talk between grapheme-processing and color processing areas exists because either:
- Excessive connections made early in development are insufficiently pruned
- There is an impairment to inhibitory systems that normally prevent cross-talk between the areas.
Grapheme-color synesthesia is one of the most common of the 150 reported forms of synaesthesia and runs in families. It can be verified through batteries that test the consistency of color associations over time, or through a kind of reverse-colorblindness test where patterns jump out at synesthetes much faster than for the rest of us.
For example, what patterns do you see here?
How about now?
Five families with four or more individuals with color sequence synesthesia were recruited into the genetic linkage study. The Eagleman group tested for synesthesia in all available members of the family and generated the following pedigrees:
In families A and E it was only observed in females, in the other families it was observed with roughly equal probabilities in both males and females. Rectangles designate males, circles designate females, and black designates a verified color sequence synesthete. Tomson (2010) Behavioural Brain Research.
24 synesthetes and 24 controls were then genotyped using a PicoGreen SNP (Single Nucleotide Polymorphism) Array for 6090 SNPs to see if any locations of DNA seemed associated with the synesthesia. A 23 Megabase region on the long arm of chromosome 16 (q12.2-q23.1) was identified in families A & B, but not C, D, or E. Indicating that mutations in this region may be one cause or predisposition for grapheme-color synesthesia, but that there may be other causes. The region contains 343 genes, so it’s hard to determine exactly which ones might be involved, but the Eagleman group proposed 6 candidates: GABARAPL2, NDRG4, PLLP, KATNB1, and CIAPIN1. These genes were sequenced in four synesthetes however none of the polymorphisms observed were duplicates and none were novel. More in depth sequencing will be required to determine the precise genes involved. Larger haplotyping studies could also uncover the regions involved in families C, D, & E.
Identifying the genes associated with grapheme-color synesthesia could answer a bigger question. Are all these disorders we call synesthesias biologically or mechanistically related to each other, or is it a diverse group of phenomena we have lumped together because of similarities in their phenotype? The discovery could also help explain observations of synesthesia during hallucinogenic drug use, mediation, or the acquisition of synesthesia from sensory loss, or by choice in the case of a 10-year-old boy with Aspergers.
Filed under: Behavior, Genetics, Human, SNPs, Uncategorized | 30 Comments
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In Search of Memory -Eric Kandel
Kandel’s book is a nobel prize winner's memoir that spans from his Jewish childhood in Nazi-occupied Vienna to his work on sea slugs that uncovered synaptic plasticity, the molecular foundation of learning and memory. When I graduated college, every neuroscience major was given a copy of this book.
Ben Kuebrich
Neuroamer 
The black and white picture of the Fs, Ps and Hs … Is that FULLY black and white? Because I’m seeing it in colour, so maybe I’m a projector synesthete without even having known! I knew I had number and month colours, but this is cool…
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Fully black and white. (Well, off-white maybe.) Crazy. How do you go without realizing that? It’s not present when you look at letters normally? Maybe it has something to do with the pattern of the letters and not the letters themselves?
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So is there a level of synesthesia where you have color associations but don’t physically see the colors? the letters looked black and white but I’ve had color associations for letters, numbers, weekdays, and months all my life, and my associations are strong enough that it seriously threw me off when they were colored with the wrong colors (like “synesthesia” and the f’s p’s and h’s). I also have a problem where if i get poked or if i see anyone else get poked in the belly button, i have a mild nervous breakdown. could that have anything to do with the mirror-touch one?
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Yeah. This is literally known as “associator’s synesthesia”.
Welcome to the club! I have it too!
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Hi Jerry. There’s a link on the sidebar on the right (below the twitter updates) that says follow. If you click that it will give you an option to follow with email. Been busy, so I haven’t updated for a while. Hopefully I’ll get to it soon.
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It’s strange… I can see all the letters in this article in color (I always thought I’m a projector), but when it comes to this pattern.. I have to concentrate really hard to see some colors on those thick, black letters.
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Hi, doesnt everybody sometimes feel other people pain, or feel like being touched when you see someone else being touched? i just recently discovered what synesthesia is, and have been thinking of times when i could feel what others are feeling, especially pain and emotions(its why i dont like watching TV dramas, and people fighting or being in awkward situations) is that what mirror synesthesia is, or am i just hyper sensitive to other peoples emotions….
I’ve read that you can only get this through genetics? the thing is i don’t know of any family members ever having it?
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The emotional feelings you describe probably fall under normal human empathy: for example feeling others awkwardness is well described an English has even borrowed a German word for it: fremdschamen. Feeling like you’re being touched when you see someone else being touched is more suggestive of mirror synesthesia. Also, just because something is genetic doesn’t mean it’s necessarily inherited, or that your relatives will have the same trait. It could be due to a rare recessive mutation in both your parents families, or you could even have a de novo mutation that neither of your parents had, though that would be quite rare, especially since these are rare conditions.
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Yes! I have that too. I’ve always felt other people’s pain, touch, etc. I never really thought it was anything until I started crying when I saw a character in a show cry. In the middle of a funny moment!
I looked around the internet and found out that it’s “Mirror-Touch Synaesthesia”. I automatically “feel” any pain, numbness, touch, etc. Though, in my case, it only seems to be when I’m paying attention, as I’m spacing out most of the time. I “feel” pain more frequently than touch, because I pay attention to injuries far more than handshakes and the likes.
But I don’t mimic emotions. Ever. Whether that’s just a slightly different form of synaesthesia than yours or because I’m “the walking definiton of impassive” (as I’ve been told), I don’t know.
It’s sort of annoying to cry, limp, get headaches, etc. without any reason, but it’s really…interesting.
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Hay! I am in the same boat with you guys! Also, pain transfers to me (someone else’s headaches, cramps, etc.) but they have to mention it. After I get it though, and I ask them about it, they tend to say it lessened. Weird, right? Nowadays, I try to ignore the world so I can go through the day pain free.
Touch is not as easily felt for me, but emotions… I can definitely feel those; however, it is harder to ‘feel’ the emotions of a close family member than a stranger. I thought this experience was normal until I heard a podcast about it and started to get curious enough to seek out more information. Could I have synesthesia?
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I believe I have mirror-touch synaesthesia… How would I go about getting a diagnosis?
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I’m really not sure. I think it’s rare, and doesn’t have much clinical relevance (health-wise anyways), so many physicians might not know about it. You might want to try to contact researchers who study it, and see if you can get involved in studies. If you find out any good info please post it here.
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Wow sounds like mirror neurons if you ask me. Wonder if it is in any way related with ASMR?
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When I see objects being touched, I can feel that. For example, when someone taps their fingers on the table, I can feel fingers on my face. And I can feel myself typing this as if I am pressing a keyboard on my face as well as feeling my self press the keys. Also, with people, I feel other people blink and can feel other people’s breathing in my own chest. I have other example too. Is this mirror touch?
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Please help.
I cant really explain this but I’v been beating myself up about it thinking I’m schizophrenic or something for ages.
I see colours around objects and people and everything, for instance right now I can see blue projecting from my red blanket, I don’t know what to do does it have to do with my eyes? Its been happening since I was aged 12, I’m now 17.
Please recommend people or doctors that I can see, and if you want more examples let me know, I’v been searching all over the internet for explanations and I can’t match with any.
Thank you
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It may just be that you are seeing the afterimages of things, which is completely normal. When you stare at something, you also start to see the opposite color. For example, looking at something red makes you see a bluish turquoise color (like the blanket you described), looking at something green makes you see a magenta color, and looking at something dark makes you see a bright color.
On this page it talks about seeing an afterimage when you look away, but it can also happen even when you’re looking straight at something, since your eyes move a little bit naturally.
http://en.wikipedia.org/wiki/Afterimage
Hopefully that’s what it is!
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I believe you are seeing auras anything that has energy can have an aura.
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AM REALLY IN NEED OF A REPLY, WHEN I TASTE SOMETHING LIKE DORITOS IT GOOD BUT WHEN I SMELL SOCKS THEY SMELL, TASTE LIKE DORITOS. AND WHEN I SEE SOMEONE GET HURT I WHENCE AND HOLD THE AREA AS IF AM HIT,AND IN AKWARED SITUATION I FEEL THE NEED TO GET OUT QUCK,AND IS IT NORMAL TO SIT AND GET PHYSICALLY GET TIRED FROM SITTING BUT BE ENERGITC WHEN PLAYING SPORTS EVEN THOUGH I HAVE NO PAST EXPERINCE OF TRAINING.
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I am sure I have Mirror Touch Synesthesia. I cannot see a person experience pain, a fall, a blow or indeed any inflicted pain without reacting in the same way a person would if actually receiving the action. As it is common for people to say “I know how that feels” I never fully realised that my reactions are far more intense. I have not seen this as a disadvantage as it has served me very well as a professional actor. I once auditioned for a TV commercial that required a parent to react to news that his son was going to die (a public health advt) and was able become immediately as upset as if this was really the case. I was given the job instantly.Even at this moment as I relate the factors I become emotional when I think of it – even though the recall about work I auditioned for and got, not an actual experience. Over the years I have learned to avoid some elements of a news items to avoid getting too distressed. But the reaction is for me very real.
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Weird question for any mirror touch synesthetes: do you feel action inflicted on people on tv, cartoons, animals. What about touching ‘body parts of the other gender’ you don’t personally have?
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I do, personally. I was a massage therapist for years, and especially skilled at what could be considered “perfect pressure” and neuromuscular therapy. I thought it was just because I knew other people’s methods of addressing particular areas, but then I later realized that I could feel what I was doing to my clients (though it doesn’t elicit the same relief as it did for them). I strongly prefer a deep tissue massage, but I’m able to vary for each individual because I *literally* feel their pain. When it comes to watching television, I feel it, but not as viscerally as I do with a live person.
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Hi, I am wondering if I might have a form of mirror-touch synaesthesia. When I see someone in a potentially dangerous situation, like crossing the road dangerously, or doing a dangerous sport (in life or in film), I get a sudden onset of pain and tingling in my hands and feet, which is quite intense for a few minutes and then lingers for a while afterwards. I am curious to know if other people experience this? Thank you in advance for your advice.
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I have mirror-touch as well as auditory-tactile and grapheme-colour to name a few. I was misdiagnosed back in ’06 as having psychotic major depression and i didn’t learn about my synaesthesia till 2011. It was a huge relief to know i wasn’t losing it and that all the things i feel are real, but it’s still rough to deal with every day; I’m also hypersensitive to sound (i peak at 19,220Hz) and i feel the vibrations against my body which makes me see and taste colours. I’m still, like many, in a position where i can’t get a hold of a medical professional who will take me seriously – i hear all the time “it’s just in your head” “you’ve gotta ignore it”; Does anyone have a recommendation of a specialist or something so i can further learn about my condition?
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Ok, you guys are beginning to freak me out… lol I was born with grapheme (letters + numbers), sound-color, and colored notes synesthesia. I did some reading on mirror-touch synesthesia and didn’t realize nobody else feels the texture of an object across their skin before they actually touch it if they focus on it.. or watch 2 people touch and feel their touch on my own skin– or join in on feeling their touch with my vision (vision-touch?). If you could explain this for me, that would actually explain a lot. No wonder I can play 2 pianos simultaneously while blindfolded, and memorize the most ridiculous concertos simply off touch.. google it. I started longboarding and come to think of it i’m beginning to feel the texture of the road with my hands, even when i’m not looking….. kind of stoked and scared simultaneously. Does any of this sound normal? I’ve never particularly noticed vision-touch before, but, I’ve always been able to physically-feel textures of any surface, object, or person across my skin using sight if I simply zone in and think about it. When I actually touch the object physically, it feels the exact same 100% of the time as when I felt the texture with my mind. That’s completely normal, right? Oddly enough, this explains a lot of strange, and relentless boners too…
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I think I have mirror touch synesthesia, but not all of it… When I see a wound or someone who’s missing a bodypart, I get a sudden ache on the place where the wound is or where the missing body part should be. This is something I hate dealing with, because if I do see these things, I might hyperventilate in the worst case scenario.
I don’t feel it when somebody’s arm just gets touched or so. I just feel it when it’s painful.
Can someone please tell me if this is something that belongs to some sort of synesthesia and what it’s called?
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Hi there,
Fascinating reading! I can’t even remember when it started but I was very young. I just instinctively knew the sex of colors, numbers and letters. As a kid in school I remember telling this to other kids…maybe teachers, I can’t remember… Red is a boy, yellow is a girl, 9 is a girl, 4 is a boy, H is a boy, U is a girl…etc. I just knew it, like it was a fact! But no one seemed to know what I was talking about, so I just stopped thinking about it.
Then I read an online article a few years ago about synesthesia and boom!! The clouds parted, the penny dropped, the fog cleared…it made complete sense to me!
But in all my reading and discovery, I haven’t heard of this particular type of association. Am I a synesthete or did I just have a vivid imagination as a kid?
Thanx!
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I have heard about this kind of association before and I guess if you google: gender, numbers, synesthisia (or something like that) you kind find information about it.
I did just that and found this wikipedia page with a fancy name for it: https://en.wikipedia.org/wiki/Ordinal_linguistic_personification
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