THE ROUGH GUIDE TO PSYCHOLOGYnicknames for some of his friends, because their real names trig-
gered unpleasant tastes). Hearing-motion synaesthetes, meanwhile, hear
beeps, whirring or tapping whenever they see movement or flashes.
Indeed, new forms of the condition are being documented all the time.
In 2008, neuroscientist V.S. Ramachandran and his colleague David
Brang described the first-ever cases of “touch-emotion synaesthesia”, in
which people experience specific emotions whenever they touch certain
textures or surfaces. For example, one participant experienced strong
disgust whenever she felt denim, while another person described feeling
perfect contentment and happiness at the feel of silk.
Synaesthesia was first described by the polymath Francis Galton in
the nineteenth century, and for a long while, much research effort was
expended on establishing whether the condition was genuine. There’s
now strong evidence that the subjective reports of synaesthetes are real.
For example, synaesthetes who say that the letter A triggers the colour
red are quicker at identifying the letter A when it is written in red ink,
rather than blue ink, just as you’d expect if their synaesthetic experi-
ence was real. Hearing-motion synaesthetes, meanwhile, are better than
normal people at judging whether two streams of visual flashes are iden-
tical, just as you’d expect if they were able to use accompanying sounds
to help them make their judgements.
More recently, research has moved on to investigating how synaes-
thesia occurs, how prevalent it is, and what the condition can tell us
about the way all our minds work. A recent study of some British
schoolchildren suggests the condition may be far more prevalent
than was previously thought. When psychologist Julia Simner and
her colleagues tested 615 children aged 6 to 7 years in 21 UK schools,
their conservative estimate was that 1.3 percent of the children had
grapheme-colour synaesthesia. They reached this conclusion by testing
the consistency with which the children associated letters and colours.
The children classified as synaesthetes were more consistent over a year
than the other children were over ten seconds! Based on their findings,
the researchers estimated that the average primary school in England
and Scotland contains two children with grapheme-colour synaesthesia.
A popular theory for synaesthesia explains the condition in terms
of excess wiring between parts of the brain involved in processing
the different senses. This makes intuitive sense but was challenged by
a study in 2008 by Roi Kadosh of University College London, which
involved hypnotizing suggestible students to make them perceive
certain numbers in certain colours. Not only did the students report