Mind Hacks™: Tips & Tools for Using Your Brain (40 page)

Just because you’re not thinking of something doesn’t mean it isn’t there just
waiting to pop into your mind. How recently you last thought of it, and whether you’ve
thought of anything related to it, affects how close to the surface an idea is.

We found this amusing when we were at school, so maybe you’ll get the best results if
you pick one of your more childish friends to try it out. For dramatic effect, claim
beforehand — as we used to — that you can read your friend’s mind. Then, ask her the following
questions in quick succession:

Most people, most of the time, say “carrot.”

Here’s something similar. Like the carrot game, it works best if you can get the
person answering the question to hurry.

Tell her to say “milk” 20 times as quickly as she can, and then, just as she
finishes, snap the question, “What do cows drink?” at her. If you’ve caught her off guard,
she’ll say “milk,” even though the answer is truly “water.”
¹

Both of these examples take advantage of the principle that things — words, in this
case — are not all equally accessible to consciousness. Some throw themselves into the
limelight of awareness, while others are more reluctant to step forward.

Carrot is pretty much at the front of our minds when the topic is vegetables
(especially after a bunch of arithmetic questions have flushed out other thoughts). With
the cow question, saying “milk” 20 times puts that word right at the front of our mind, so
much so that it gets out before we correctly parse the question.

This is all well and good if you want to know that a carrot is most people’s
prototypical vegetable or that they can be easily flustered if you get them to do
something ridiculous like say “milk” 20 times.

But there is a valuable tool here for experimental psychologists as well. Encountering
a word brings it forward in your mind. If you’ve heard a word a short while before, you
are quicker to recognize it, quicker to make decisions about it, and more likely to
volunteer it as an answer. You don’t have to use just words — pictures and sounds too are
more easily recognized after prior exposure.

The interesting thing is that these effects — called
priming —
persist after people have consciously forgotten that they
have seen the item or even if they weren’t aware of seeing the word at all
[
Subliminal Messages Are Weak and Simple
]
.
The automatic nature of this effect allows cognitive psychologists to use it in a variety
of tests to check whether people have been able to perceive material that they either
weren’t aware of at the time or have forgotten seeing. Psychologists call this kind of
memory, which is revealed by performance rather than by explicit recall, implicit
memory.

It has also become clear that things that are linked in your mind are primed by
exposure to related things. So if you show someone the word “doctor,” he finds it easier
to subsequently detect the word “nurse” if the word appears covered by TV snow (the visual
equivalent of white noise). Or if you show someone the word “red,” he is more likely to
complete a word stem like
gr___
with the word “green.” If you show
him the word “wine,” he is more likely to complete with the word “grape.” Both are valid
answers, but the likelihood of one or the other being the first that comes to mind is
affected by what other items have been primed in the mind.

We can think of all mental items being connected in a web of semantic units.
When you see an item, it becomes activated, so that for a short while it is easier for it
to reach a threshold of activity that pushes it into consciousness or allows you to
recognize it. Activity can spread between related items in the web; sometimes this
activity can influence your behavior in interesting ways
[
You Are What You Think
]
.

Primed concepts hover just below conscious thought, ready to pop out at a moment’s
notice. It is probably this priming that underlies the phenomenon in which, having learned
a new word, you suddenly see it everywhere. The word is near the front of your mind and so
all the times you would have otherwise ignored it become times when you now notice it. And
when you’re hungry, everything reminds you of food.

Priming happens all the time; we’re constantly noticing new things, bringing stuff to
mind, and making associations. The interesting thing is that it is a two-way process, and
one we underestimate. No one is surprised that the things we notice affect what we think
of. Less often people account for the things we’re thinking of affecting what we notice.
More subtly, that which we noticed, even briefly and then forgot, influences both what we
think
and
what we notice in the future. It feels like the same “you”
who walks down the street every day, but what catches your eye and what occupies your mind
are going to be different, in part, based on your TV viewing the night before, whether
you’re thinking about TV or not. It’s not an intuitive thing to be able to account for,
but it’s part of the constant sifting and sorting of mental items that makes up our mental
life.

Subliminal perception sneaks underneath the level of consciousness and can influence
your preferences — but only a little.

Proving that mere exposure can change your preferences isn’t easy to do at home, so
it’s best to look at the experiments. Robert Bornstein and Paul D’Agostino exposed a group
of volunteers to images, either photographs or unfamiliar shapes, and then asked each
person to rate the images according to how much he or she liked them.
¹

If you were one of those volunteers, you’d have spent 5–10 minutes at the beginning of
the experiment being exposed to images for only 5 milliseconds each. That’s a tiny amount
of time for vision, only as long as a quarter of one frame of television. Exposed to a
picture for that long, you’re not even aware you’ve seen it. As a volunteer, you could be
shown the picture later to look at, and it’s as if you’re seeing it for the first
time.

When you’re asked which images you prefer out of a larger selection, you’ll rate
images you were exposed to but can’t recall seeing higher.

The rating exercise is a little like the game Hot or Not (
http://www.hotornot.com
) but with some of the photos flashed up at you faster than you can make them
out beforehand. In Hot or Not, you see a photo of a person and rate it: 10 being Hot and 1
being Not. The web page then immediately reloads with another photo for you to rate, and
you can also see how your score on the previous photo compared to what everyone else
said.

All else being equal — all the photos being equally attractive — let’s pretend you’re
rating all the photos 5 on average.

If you’d had the photo flashed up at you 20 times in that initial batch of
image exposure, for only 5 ms each time (less than a tenth of a second in total!), you
might rate that photo not a 5, but a 6.

Two things are going on here. The first is subliminal perception. The visual system
has just enough time to get the image presented into the brain, but not enough to process
it fully to conscious awareness. In addition to subliminal perception, there is a priming
[
Bring Stuff to the Front of Your Mind
]
effect. Whenever some perception reaches the brain, the neurons that are
involved in that representation persist in their activity for a while, and if you
experience that thing again, your neurons respond more readily to it.

So when your perception of a particular face has been subliminally primed, when you
see the photograph again, properly, your brain reports a very slight sense of familiarity.
But because you can’t actually recall seeing the photo before, you misinterpret this
feeling as preference: you like the face in the photo more than you otherwise would have
done.

Mere exposure is the phenomena behind the urban legend of subliminal perception, in
which the words “Hungry? Eat popcorn” repeatedly flashed up (too fast to consciously see)
during a movie is supposed to result in a colossal increase in popcorn consumption. It’s
correct inasmuch as repeated exposures lead to a stronger priming effect, and therefore a
slightly stronger preference — but that’s all.

The experiments that led to the “Hungry? Eat popcorn” legend were fabricated in the 1950s.
²
What mere exposure can do is slightly influence you if you’re undecided
about which goal to pursue. Being exposed to a picture of a particular chocolate bar could
encourage you to pick out that bar if you’re standing at a counter with a dozen different
bars a few minutes later. What mere exposure
can’t
do is give you an
overpowering hunger to stand up, walk off, and find that chocolate, or even make you buy
chocolate if you’ve already decided you want chips.

Nor can mere exposure influence you with complicated instructions. There’s
barely enough time for the image of the three words “Hungry? Eat popcorn” to bump through
your visual production line, to make a representation in your brain, but certainly not
enough for the words to be understood as a sentence. A photograph, a shape, or a single
word is as far as it goes.