Mirror-touch synesthesia
Also called: Mirror-touch synaesthesia
About 1 in 60 people feel a touch on their own body when they watch someone else being touched. The brain system that mirrors other people's actions appears to be turned up too high.
How common
Can you do this?
How it works
When you watch a person being tapped on the cheek, parts of your own touch cortex become slightly active. This happens in most people and is part of how the brain understands other people’s actions13. The leading theory is that in mirror-touch synesthesia this activity crosses a threshold and becomes a felt touch1. Some people feel it on the same side they see. Others feel it mirrored, as if they were looking in a mirror1.
The first case was reported in 2005 by Sarah-Jayne Blakemore and colleagues at University College London4. Brain scans showed that watching touch produced stronger activity in the somatosensory cortex of the synesthete than in control subjects1. Like other forms of synesthesia, it is stable over time and starts in childhood2.
The touch can be unpleasant. Some people with the condition avoid films with violence because they feel the blows.
A popular claim says mirror-touch synesthetes are unusually empathic. Early studies found slightly higher scores on emotional empathy questionnaires1. A larger 2016 study did not confirm this, and it found higher autism-spectrum scores in the group instead6. Feeling a mirrored touch is a sensory event. It is not the same as understanding another person. The idea that mirror-touch means super-empathy is not supported.
How common it is
The 1.6% figure comes from a 2009 screening study of university students, using a questionnaire and a touch-observation task, not a broad population census5. University samples skew young and skew toward one kind of background, so the true rate in the wider population is not firmly known. Most people who have it never learn that it has a name, since feeling a touch while watching someone else be touched can simply feel normal to them.
Is it a problem?
No. Synesthesia is not listed as a disorder, and most synesthetes describe their experiences as neutral or pleasant2. It does not mean a person is unusually empathic, and a 2016 study found no consistent empathy boost from having it6.
Mention it to a doctor only if the felt touch:
- is frequent,
- is distressing,
- gets in the way of daily activities like watching films or being in crowds.
Support strategies exist for that.
Sources and further material
- Wikipedia Mirror-touch synesthesia Blakemore et al., 2005, first case. Banissy et al., 2009, prevalence. Baron-Cohen et al., 2016, empathy and autism scores.
- Wikipedia Synesthesia
- Wikipedia Mirror neuron
- doi.org Somatosensory activations during the observation of touch and a case of vision-touch synaesthesia Brain. The first report of mirror-touch synesthesia, in subject C.
- doi.org Mirror-touch and ticker tape experiences in synesthesia Frontiers in Psychology. Describes the Banissy et al., 2009 screening of 567 undergraduates and its conservative 1.6% estimate.
- doi.org Mirror-Touch Synaesthesia Is Not Associated with Heightened Empathy, and Can Occur with Autism PLOS ONE. The largest sample of mirror-touch synesthetes to date. No enhanced empathy, and higher autistic trait scores.
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Related oddities
Synesthesia
In some people, one sense triggers another. Letters have colours, sounds have shapes, or days of the week sit in fixed places in space. The pairings are automatic and stay largely the same over many years.
Rubber hand illusion
Stroke a rubber hand and a person's hidden real hand at the same time, and within a minute or two the brain adopts the rubber hand as its own. It shows that your sense of your body is built moment by moment from sight and touch.
Cutaneous rabbit illusion
A few quick taps at the wrist followed by taps at the elbow feel like a small animal hopping up the arm. The brain fills in taps between the two spots that never happened.
Referred pain
Pain from an internal organ often shows up somewhere else, like the left arm during a heart attack or the shoulder blade from a gallbladder. The nerves from the organ and from that patch of skin share a line into the spinal cord.