UBC Reports | Vol.
50 | No. 1 | Jan.
Mapping the Sixth Sense
Psychology's Ron Rensink discovers visual sensing
By Erica Smishek
Most of us have felt it before -- that sinking feeling that
something is about to happen, that something is not quite
right. It's the stuff of scary movies, X-Files episodes
and psychic visits.
But according to a new study by Ron Rensink, an associate
professor in both psychology and computer science at UBC,
the "sixth sense" is a distinct mode of visual
perception and may be something all of us can learn to employ.
He calls it "mindsight" -- the phenomenon where
people can sense a change but do not see it (i.e. have a visual
experience of it) for several seconds.
"There is something there -- people do have access
to this other subsystem," says Rensink, whose findings
appear in the January issue of Psychological Science.
"Vision is not just one ability, it's not just
one sense. There is vision for conscious perception -- this
picture you have of what's going on -- and there is
also vision for action. It turns out these are two very different
subsystems -- one of them is conscious, one of them is non-conscious
-- and they actually work slightly differently. That's
why when you're driving, for example, you can actually
tune out and you can drive just fine because this other system
In a preliminary experiment initially designed to test attention,
Rensink presented participants with a photograph of a real-world
scene and a modified photograph in a sequence, with a brief
gray field between successive images. Participants were asked
to hit a button when they saw a change.
But some participants asked if they should hit the button
when they actually saw the change -- or when they first felt
Intrigued, Rensink re-jigged the experiment. Forty participants
were instead asked to hit a button once when they sensed a
change -- that is, had a "feeling" that a change
was occurring - and a second time when they actually saw the
Most participants only saw the change. But some sensed a
change two or three seconds before they actually saw it.
"About a third of people seem to get this feeling of
something happening, of something changing," says Rensink.
"You can't really say what it is, you can't
really say when it is. It's just a gut feeling... It's
clear whatever it is, they're using it in their everyday
A noted vision researcher, Rensink spent six years at Cambridge
Basic Research, a partnership involving the Massachusetts
Institute of Technology, Harvard and Nissan Motor Co. Prompted
in part by a finding that accidents in city driving were often
classified as "driver looked but failed to see,"
he initially studied "change blindness" (people's
blindness to scene changes) and later conducted the experiments
that were part of the mindsight findings.
"In the past, people believed that if light came into
your eyes, it would have to result in a picture. If it didn't
result in a picture, it must mean that it can't be vision.
"What I'm saying is no, that first assumption
is wrong. Light can come into your eyes and do other things.
There are other perceptual systems and it can result in other
forms of experience. It's all vision -- it's just
a different kind of vision. There is nothing really magical
about it. It's just a different way of perceiving, so
it's a different kind of experience, which I think is
actually pretty cool. This is not magical."
But it is controversial.
"It's not going to make everybody happy,"
he says matter-of-factly of findings that took more than two
years -- and significant verification -- to publish.
"A lot of people feel kind of threatened by this, by
the idea that the conscious mind is not necessarily the ultimate
in terms of intelligence or control. If you think that the
conscious mind is the end-all and be-all, this kind of work
Rensink says people need to trust their gut instincts and
believes we can likely train ourselves to hone them.
"In the longer run, it's worth taking a look
at intuition to get more insight into this area," he
says. "Maybe this will tend to lead people to develop
their intuitions and realize that these intuitions are informative
and we should respect them. This may help us in all kinds
In practical terms, Rensink, who is part of a team of UBC
researchers investigating the possibilities of intelligent
human-automobile interfaces, says if one can actually induce
this gut feeling, scientists may be able to use it in cars
as a kind of warning.
"What you'd like is a way to say, ‘slow
down, or dangerous curve ahead.' If you're getting
a feeling that something is not quite right, this may in fact
get people to be more cautious."
He also thinks it could be applied to the arts, used deliberately,
for example, in the cinema to give the audience an even "spookier
Rensink plans further analysis to determine what may separate
people who have this sense from people who don't. Is
it a personality variable? Is it attitude or mental set? And
what part of the brain is responsible?
"If people are capable of this, they are probably capable
of a lot more," he says. "We just don't
know yet. We'll see where it leads us in the future.
It could be the start of something interesting -- a whole
other way of using vision."