Do we all have some synaesthetic ability?
New Scientist, 30 September 2008
ALISON MOTLUK
So, you
think you're not synaesthetic. You might have to think again. New
research shows that many people have traces of the condition without
realising it.
Synaesthesia is a condition in which people make unusual associations across the sensesMovie Camera.
Some
people perceive letters, numbers, words and smells to have innate
colours, while others can taste music or imagine time to have a fixed
special form.
Ferrinne Spector and Daphne Maurer at McMaster
University in Hamilton, Canada, were interested in exploring the
coloured and textured smell that some synaesthetes experience.
Smells green
They
asked 78 people who considered themselves non-synaesthetes to smell 22
separate odours in glass jars and assign each a colour and a texture.
The
experiment included odours that were both pleasant and unpleasant and
familiar and unfamiliar, and that fitted broadly into four categories:
food, floral, chemical and environmental. Volunteers were asked to look
beyond the obvious, say, orange for an orange scent.
When the
researchers analysed the results, along with some obvious associations
- lemon with yellow and peppermint with smooth, hard and sticky - they
found some odd ones.
Significantly more people than chance, for
instance, associated the smell of mushrooms with the colours blue or
yellow. Lavender elicited the colour green and the texture of sticky
liquid, while ginger was perceived as black and sharp.
"The
influence of learning is there," Spector told a meeting of the American
Synesthesia Association in Hamilton on 27 September, "but it cannot
explain all associations."
Curved time
In a separate
experiment, Ursina Teuscher, at the University of California at San
Diego, and her colleagues asked 191 people whether they saw the months
in a spatial arrangement. Eighty-nine said they did not.
But
when the researchers asked volunteers to click on a computer screen to
plot where they perceived months to be, non-synaesthetes produced
similar arrangements to synaesthetes - including straight lines, curvy
lines, ovals, circles and rectangles.
Some were so consistent
with synaesthete representations that the researchers decided to divide
them not by whether they declared themselves a synaesthete or not, but
rather by their accuracy in replicating their own mental
representation. "More consistency predicts a less conventional
calendar," Teuscher told the meeting.
Teuscher called for
researchers of synaesthesia to be more rigorous. She pointed out that
they are all very careful to make sure professed synaesthetes meet the
criteria before considering them bona fide synaesthetes, but less so
the other way round.
"If people say they don't have
synaesthesia, we feel we don't have to validate that," she says, "and
maybe that's a big mistake."