STEPHEN KOSSLYN: For the last 30 years Ive been
obsessed with a question: What shape are a German Shepherds
ears? Of course, I'm not literally interested in that
question, since if I were I could just go out and look
at dogs; Im really interested in how people answer
the question from memory. Most people report that they
visualize the dogs head and mentally "look
at" its ears. But what does it mean to visualize
something? What does it mean to "look at it in
your mind"? It's a bit absurd, because there can't
be a little man in there that is actually looking at
a picture. If there were, there would have to be a little
man inside that man's head, and so forth, and it doesn't
make any sense.
For many years we tried to collect objective evidence
to show that when you have the experience of visualizing,
theres actually something pictorial in your head.
It turned out that the best way to approach this was
by turning to the brain. There are parts of the brain
that are physically organized such that when you look
at something, a corresponding pattern is physically
laid out on the cortex. Even the first visual area in
the processing stream is often activated during visual
imagery even if your eyes are closed when you visualize.
Moreover, the way it's activated depends on what youre
visualizing. If you visualize something thats
vertical, you find activation along the so-called vertical
meridian ; if its horizontal, the activation flips
over on its side. Its absolutely amazing. Similarly,
visualizing objects at different sizes changes the pattern
of activation in ways very much like what occurs if
you are actually seeing objects at the corresponding
But Ive been working on this for over 30 years
now and I want to move on. Instead of trying just to
establish that there actually are mental images and
that these images are bona fide representations that
have a functional role in processing systems, I want
to ask: So what? Who cares? Why should my mother be
interested in this kind of thing?
Lately Ive been working on something that I'm
tentatively calling the "Reality Simulation Principle."
It is built on my lab's findings that about two-thirds
of the same brain areas are involved in visual mental
imagery and visual perception. This finding occurs even
when the tasks seem very different on the surface (for
example, visualizing an upper case letter in a grid
and deciding whether an X mark would fall on the letter
if it were actually in the grid versus deciding whether
a spoken name is appropriate for a picture). This is
a huge amount of overlap, which leads us to suspect
that an object seen in a mental image can have the same
impact on the mind and body that the actual object would
have. My notion is that once the brain systems are engaged,
they don't know where the impetus came from. This means
that they can produce the same effects whether you activated
it endogenously (from information in memory) or exogenously
(from looking at something).
The "Reality Simulation Principle" describes
how to use mental images as stand-ins for actual objectsto
manipulate yourself, basically. It is useful to understand
it in conjunction with what I call the GITI cycle, which
stands for Generate, Inspect, Transform, Inspect. If
mental images can simulate or stand in for actual objects
and scenes, you can generate the image, inspect what
youve got, transform it, and inspect the result.
This can be done iteratively, meaning that you can use
imagery to take advantage of the "Reality Simulation
Principle"to do all sorts of good things for yourself.
What kinds of good things am I talking about? Memory
is one obvious example. From the work of Alan Paivio
and countless others, we know that youre able
to remember objects better than pictures of objects,
and pictures of objects better than words. It also turns
out that if you visualize the objects named by words
you do better than you would otherwise. Consequently,
we're interested now in things like hypnosis. We can
hypnotize you, have you visualize an object, and imagine
that its actually a three-dimensional object,
appearing in glorious vivid detail. In this case, your
memory would be boosted even further.
Mental practice is another candidate. Neuroscientists
such as Marc Jeannerod and Jean Decety have shown that
imagining doing something recruits most of the brain
mechanisms that would guide the corresponding actual
movements. And people in sports psychology have shown
that by imagining that youre engaging in some
activity youll actually get better at doing it.
This process involves generating an image, inspecting
the image, transforming it by imagining your movements,
seeing what the result would be, and then cycling through
again. The next time through you can change the image
as a function of the result you saw. If you imagine
youre playing golf, for example, and your ball
doesnt get in the hole, you can imagine what would
happen if you whacked it a little more softly. Mental
practice clearly works. By understanding how mechanisms
of imagery works we can actually optimize this mental
"Reality Simulation Principle" can also be
used to acquire self-knowledge. Try this one out. Imagine
its dusk, youre walking alone, and youre
late. You start to walk faster and then notice a short-cut
through an alley. Its getting a little dark, but
you really dont want to be late, so you start
to go towards it, and you notice that there are three
guys lingering near the mouth of the alley. Now think
about a first scenario: The three guys look like theyre
20 years old, are wearing long droopy shorts, dirty
t-shirts, baseball caps that are on backwards, and are
smoking cigarettes. As you get close, they stop talking,
and all three heads swivel and fixate on you and start
tracking you. How do you feel?
Now try the same thing, except instead of those three
guys, make them three balding middle-age, overweight
accountants wearing suits. Theyre standing there
smoking cigarettes, and their heads swivel as they track
you. How do you feel now?
You can start simulating the effects of different attributes.
For example, what if the guys are black or Latino teenagers.
How do you feel? If you can start actually sorting out
your own emotional landscape by running these kinds
of mental simulations, you may, in fact, discover certain
things about yourself that may be surprising.