0:00:17.390,0:00:19.575
Vision is the most important

0:00:19.575,0:00:22.042
and prioritized sense that we have.

0:00:22.042,0:00:23.889
We are constantly looking

0:00:23.889,0:00:25.542
at the world around us,

0:00:25.542,0:00:27.972
and quickly we identify and make sense

0:00:27.972,0:00:29.744
of what it is that we see.

0:00:29.744,0:00:31.742
Let's just start with an example

0:00:31.742,0:00:33.100
of that very fact.

0:00:33.100,0:00:35.333
I'm going to show you[br]a photograph of a person,

0:00:35.333,0:00:36.800
just for a second or two,

0:00:36.800,0:00:38.729
and I'd like for you to identify

0:00:38.729,0:00:41.003
what emotion is on his face.

0:00:41.003,0:00:42.188
Ready?

0:00:42.188,0:00:45.076
Here you go. Go with your gut reaction.

0:00:45.345,0:00:47.060
Okay. What did you see?

0:00:47.060,0:00:49.316
Well, we actually surveyed

0:00:49.316,0:00:51.358
over 120 individuals,

0:00:51.358,0:00:53.689
and the results were mixed.

0:00:53.689,0:00:55.594
People did not agree

0:00:55.594,0:00:58.583
on what emotion they saw on his face.

0:00:58.583,0:01:00.794
Maybe you saw discomfort.

0:01:00.794,0:01:02.661
That was the most frequent response

0:01:02.661,0:01:04.095
that we received.

0:01:04.095,0:01:06.116
But if you asked the person on your left,

0:01:06.116,0:01:08.870
they might have said regret or skepticism,

0:01:08.870,0:01:10.772
and if you asked somebody on your right,

0:01:10.772,0:01:13.249
they might have said[br]something entirely different,

0:01:13.249,0:01:15.538
like hope or empathy.

0:01:16.143,0:01:17.777
So we are all looking

0:01:17.777,0:01:20.336
at the very same face again.

0:01:20.336,0:01:22.473
We might see something

0:01:22.473,0:01:24.789
entirely different,

0:01:24.789,0:01:27.474
because perception is subjective.

0:01:27.474,0:01:29.277
What we think we see

0:01:29.277,0:01:31.580
is actually filtered

0:01:31.580,0:01:33.827
through our own mind's eye.

0:01:33.827,0:01:36.314
Of course, there are many other examples

0:01:36.314,0:01:38.874
of how we see the world[br]through own mind's eye.

0:01:38.874,0:01:40.801
I'm going to give you just a few.

0:01:40.801,0:01:43.122
So dieters, for instance,

0:01:43.122,0:01:45.053
see apples as larger

0:01:45.053,0:01:48.130
than people who are not counting calories.

0:01:48.130,0:01:51.274
Softball players see the ball as smaller

0:01:51.274,0:01:53.680
if they've just come out of a slump,

0:01:53.680,0:01:57.580
compared to people who had[br]a hot night at the plate.

0:01:57.580,0:02:00.259
And actually, our political beliefs also

0:02:00.259,0:02:02.642
can affect the way we see other people,

0:02:02.642,0:02:04.795
including politicians.

0:02:04.795,0:02:08.263
So my research team and I[br]decided to test this question.

0:02:08.263,0:02:12.232
In 2008, Barack Obama[br]was running for president

0:02:12.232,0:02:13.532
for the very first time,

0:02:13.532,0:02:16.497
and we surveyed hundreds of Americans

0:02:16.497,0:02:18.825
one month before the election.

0:02:18.825,0:02:20.729
What we found in this survey

0:02:20.729,0:02:23.260
was that some people, some Americans,

0:02:23.260,0:02:24.839
think photographs like these

0:02:24.839,0:02:27.470
best reflect how Obama really looks.

0:02:27.470,0:02:29.927
Of these people, 75 percent

0:02:29.927,0:02:32.665
voted for Obama in the actual election.

0:02:32.665,0:02:35.544
Other people, though,[br]thought photographs like these

0:02:35.544,0:02:38.331
best reflect how Obama really looks.

0:02:38.331,0:02:40.322
89 percent of these people

0:02:40.322,0:02:42.278
voted for McCain.

0:02:42.278,0:02:45.621
We presented many photographs of Obama

0:02:45.621,0:02:47.397
one at a time,

0:02:47.397,0:02:50.003
so people did not realize[br]that what we were changing

0:02:50.003,0:02:52.032
from one photograph to the next

0:02:52.032,0:02:53.996
was whether we had artificially lightened

0:02:53.996,0:02:56.249
or darkened his skin tone.

0:02:56.249,0:02:58.138
So how is that possible?

0:02:58.138,0:03:00.838
How could it be[br]that when I look at a person,

0:03:00.838,0:03:02.514
an object, or an event,

0:03:02.514,0:03:04.717
I see something very different

0:03:04.717,0:03:06.617
than somebody else does?

0:03:06.617,0:03:08.750
Well, the reasons are many,

0:03:08.750,0:03:10.970
but one reason requires that we understand

0:03:10.970,0:03:13.665
a little bit more about how our eyes work.

0:03:13.665,0:03:15.705
So vision scientists know

0:03:15.705,0:03:17.501
that the amount of information

0:03:17.501,0:03:18.546
that we can see

0:03:18.546,0:03:20.746
at any given point in time,

0:03:20.746,0:03:23.703
what we can focus on,[br]is actually relatively small.

0:03:23.703,0:03:25.976
What we can see with great sharpness

0:03:25.976,0:03:28.137
and clarity and accuracy

0:03:28.137,0:03:29.840
is the equivalent

0:03:29.840,0:03:32.297
of the surface area of our thumb

0:03:32.297,0:03:34.637
on our outstretched arm.

0:03:34.637,0:03:37.075
Everything else around that is blurry,

0:03:37.075,0:03:39.540
rendering much of what is presented

0:03:39.540,0:03:41.813
to our eyes as ambiguous.

0:03:41.813,0:03:44.290
But we have to clarify

0:03:44.290,0:03:46.520
and make sense of what it is that we see,

0:03:46.520,0:03:49.887
and it's our mind[br]that helps us fill in that gap.

0:03:49.887,0:03:53.477
As a result, perception[br]is a subjective experience,

0:03:53.477,0:03:55.185
and that's how we end up seeing

0:03:55.185,0:03:57.493
through our own mind's eye.

0:03:57.493,0:03:59.397
So, I'm a social psychologist,

0:03:59.397,0:04:01.061
and it's questions like these

0:04:01.061,0:04:02.735
that really intrigue me.

0:04:02.735,0:04:04.319
I am fascinated by those times

0:04:04.319,0:04:06.660
when people do not see eye to eye.

0:04:06.660,0:04:08.328
Why is it that somebody might

0:04:08.328,0:04:10.534
literally see the glass as half full,

0:04:10.534,0:04:12.608
and somebody literally sees it

0:04:12.608,0:04:14.256
as half empty?

0:04:14.256,0:04:17.058
What is it about what one person[br]is thinking and feeling

0:04:17.058,0:04:18.771
that leads them to see the world

0:04:18.771,0:04:20.890
in an entirely different way?

0:04:20.890,0:04:23.072
And does that even matter?

0:04:23.072,0:04:25.858
So to begin to tackle these questions,

0:04:25.858,0:04:28.475
my research team and I[br]decided to delve deeply

0:04:28.475,0:04:30.706
into an issue that has received

0:04:30.706,0:04:32.570
international attention:

0:04:32.570,0:04:34.536
our health and fitness.

0:04:34.536,0:04:35.801
Across the world,

0:04:35.801,0:04:38.213
people are struggling[br]to manage their weight,

0:04:38.213,0:04:40.277
and there is a variety of strategies

0:04:40.277,0:04:43.445
that we have to help us[br]keep the pounds off.

0:04:43.445,0:04:47.015
For instance, we set[br]the best of intentions

0:04:47.015,0:04:48.956
to exercise after the holidays,

0:04:48.956,0:04:51.771
but actually, the majority of Americans

0:04:51.771,0:04:54.074
find that their New Year's resolutions

0:04:54.074,0:04:56.912
are broken by Valentine's Day.

0:04:56.912,0:04:58.862
We talk to ourselves

0:04:58.862,0:05:00.537
in very encouraging ways,

0:05:00.537,0:05:02.422
telling ourselves this is our year

0:05:02.422,0:05:04.118
to get back into shape,

0:05:04.118,0:05:06.080
but that is not enough to bring us back

0:05:06.080,0:05:07.424
to our ideal weight.

0:05:07.424,0:05:09.266
So why?

0:05:09.266,0:05:11.538
Of course, there is no simple answer,

0:05:11.538,0:05:13.853
but one reason, I argue,

0:05:13.853,0:05:15.673
is that our mind's eye

0:05:15.673,0:05:17.552
might work against us.

0:05:17.552,0:05:20.696
Some people may literally see exercise

0:05:20.696,0:05:22.409
as more difficult,

0:05:22.409,0:05:24.096
and some people might literally

0:05:24.096,0:05:26.455
see exercise as easier.

0:05:26.455,0:05:29.947
So, as a first step[br]to testing these questions,

0:05:29.947,0:05:32.493
we gathered objective measurements

0:05:32.493,0:05:34.805
of individuals' physical fitness.

0:05:34.805,0:05:37.327
We measured the circumference[br]of their waist,

0:05:37.327,0:05:40.230
compared to the circumference[br]of their hips.

0:05:40.230,0:05:42.296
A higher waist-to-hip ratio

0:05:42.296,0:05:44.750
is an indicator of being[br]less physically fit

0:05:44.750,0:05:47.266
than a lower waist-to-hip ratio.

0:05:47.266,0:05:49.107
After gathering these measurements,

0:05:49.107,0:05:50.810
we told our participants

0:05:50.810,0:05:52.869
that they would walk to a finish line

0:05:52.869,0:05:54.370
while carrying extra weight

0:05:54.370,0:05:56.123
in a sort of race.

0:05:56.123,0:05:57.910
But before they did that,

0:05:57.910,0:05:59.896
we asked them to estimate the distance

0:05:59.896,0:06:01.561
to the finish line.

0:06:01.561,0:06:04.192
We thought that the physical states[br]of their body

0:06:04.192,0:06:07.359
might change how they perceived[br]the distance.

0:06:07.359,0:06:09.125
So what did we find?

0:06:09.125,0:06:11.529
Well, waist-to-hip ratio

0:06:11.529,0:06:14.292
predicted perceptions of distance.

0:06:14.292,0:06:17.171
People who were out of shape and unfit

0:06:17.171,0:06:19.324
actually saw the distance[br]to the finish line

0:06:19.324,0:06:20.957
as significantly greater

0:06:20.957,0:06:23.084
than people who were in better shape.

0:06:23.084,0:06:24.996
People's states of their own body

0:06:24.996,0:06:27.814
changed how they perceived[br]the environment.

0:06:27.814,0:06:30.128
But so too can our mind.

0:06:30.128,0:06:32.073
In fact, our bodies and our minds

0:06:32.073,0:06:33.634
work in tandem

0:06:33.634,0:06:36.525
to change how we see the world around us.

0:06:36.525,0:06:38.665
That led us to think that maybe people

0:06:38.665,0:06:40.107
with strong motivations

0:06:40.107,0:06:41.802
and strong goals to exercise

0:06:41.802,0:06:44.519
might actually see[br]the finish line as closer

0:06:44.519,0:06:48.001
than people who have weaker motivations.

0:06:48.001,0:06:50.246
So to test whether motivations

0:06:50.246,0:06:53.745
affect our perceptual[br]experiences in this way,

0:06:53.745,0:06:55.800
we conducted a second study.

0:06:55.800,0:06:58.274
Again, we gathered objective measurements

0:06:58.274,0:07:00.261
of people's physical fitness,

0:07:00.261,0:07:02.426
measuring the circumference of their waist

0:07:02.426,0:07:04.457
and the circumference of their hips,

0:07:04.457,0:07:07.359
and we had them do[br]a few other tests of fitness.

0:07:07.359,0:07:09.778
Based on feedback that we gave them,

0:07:09.778,0:07:11.853
some of our participants told us

0:07:11.853,0:07:14.331
they're not motivated[br]to exercise any more.

0:07:14.331,0:07:16.762
They felt like they already met[br]their fitness goals

0:07:16.762,0:07:18.841
and they weren't going[br]to do anything else.

0:07:18.841,0:07:20.566
These people were not motivated.

0:07:20.566,0:07:22.680
Other people, though,[br]based on our feedback,

0:07:22.680,0:07:25.018
told us they were highly motivated[br]to exercise.

0:07:25.018,0:07:27.827
They had a strong goal[br]to make it to the finish line.

0:07:27.827,0:07:30.832
But again, before we had them[br]walk to the finish line,

0:07:30.832,0:07:32.743
we had them estimate the distance.

0:07:32.743,0:07:34.623
How far away was the finish line?

0:07:34.623,0:07:36.660
And again, like the previous study,

0:07:36.660,0:07:38.658
we found that waist-to-hip ratio

0:07:38.658,0:07:40.554
predicted perceptions of distance.

0:07:40.554,0:07:44.391
Unfit individuals saw[br]the distance as farther,

0:07:44.391,0:07:46.722
saw the finish line as farther away,

0:07:46.722,0:07:48.640
than people who were in better shape.

0:07:48.640,0:07:50.846
Importantly, though, this only happened

0:07:50.846,0:07:52.682
for people who were not motivated

0:07:52.682,0:07:54.289
to exercise.

0:07:54.289,0:07:55.854
On the other hand,

0:07:55.854,0:07:58.589
people who were highly motivated[br]to exercise

0:07:58.589,0:08:00.985
saw the distance as short.

0:08:00.985,0:08:03.563
Even the most out of shape individuals

0:08:03.563,0:08:05.189
saw the finish line

0:08:05.189,0:08:06.813
as just as close,

0:08:06.813,0:08:08.578
if not slightly closer,

0:08:08.578,0:08:11.010
than people who were in better shape.

0:08:11.010,0:08:12.827
So our bodies can change

0:08:12.827,0:08:15.243
how far away that finish line looks,

0:08:15.243,0:08:19.259
but people who had committed[br]to a manageable goal

0:08:19.259,0:08:21.364
that they could accomplish[br]in the near future

0:08:21.364,0:08:23.524
and who believed that they were capable

0:08:23.524,0:08:25.134
of meeting that goal

0:08:25.134,0:08:28.205
actually saw the exercise as easier.

0:08:28.942,0:08:30.645
That led us to wonder,

0:08:30.645,0:08:32.957
is there a strategy that we could use

0:08:32.957,0:08:34.754
and teach people that would help

0:08:34.754,0:08:37.331
change their perceptions of the distance,

0:08:37.331,0:08:39.858
help them make exercise look easier?

0:08:39.858,0:08:42.603
So we turned[br]to the vision science literature

0:08:42.603,0:08:44.547
to figure out what should we do,

0:08:44.547,0:08:47.040
and based on what we read,[br]we came up with a strategy

0:08:47.040,0:08:49.822
that we called,[br]"Keep your eyes on the prize."

0:08:49.822,0:08:52.114
So this is not the slogan

0:08:52.114,0:08:54.004
from an inspirational poster.

0:08:54.004,0:08:56.219
It's an actual directive

0:08:56.219,0:08:58.671
for how to look around your environment.

0:08:58.671,0:09:01.239
People that we trained in this strategy,

0:09:01.239,0:09:04.887
we told them to focus their attention[br]on the finish line,

0:09:04.887,0:09:06.843
to avoid looking around,

0:09:06.843,0:09:08.423
to imagine a spotlight

0:09:08.423,0:09:10.016
was shining on that goal,

0:09:10.016,0:09:12.391
and that everything around it was blurry

0:09:12.391,0:09:14.544
and perhaps difficult to see.

0:09:14.544,0:09:16.339
We thought that this strategy

0:09:16.339,0:09:18.817
would help make the exercise look easier.

0:09:18.817,0:09:20.505
We compared this group

0:09:20.505,0:09:22.245
to a baseline group.

0:09:22.245,0:09:23.699
To this group we said,

0:09:23.699,0:09:25.289
just look around the environment

0:09:25.289,0:09:26.722
as you naturally would.

0:09:26.722,0:09:28.277
You will notice the finish line,

0:09:28.277,0:09:29.885
but you might also notice

0:09:29.885,0:09:31.766
the garbage can off to the right,

0:09:31.766,0:09:34.578
or the people and the lamp post[br]off to the left.

0:09:34.578,0:09:36.721
We thought that people[br]who used this strategy

0:09:36.721,0:09:38.793
would see the distance as farther.

0:09:38.793,0:09:41.107
So what did we find?

0:09:41.107,0:09:43.075
When we had them estimate the distance,

0:09:43.075,0:09:44.690
was this strategy successful

0:09:44.690,0:09:46.980
for changing their perceptual experience?

0:09:46.980,0:09:48.368
Yes.

0:09:48.368,0:09:50.597
People who kept their eyes on the prize

0:09:50.597,0:09:53.452
saw the finish line as 30 percent closer

0:09:53.452,0:09:55.150
than people who looked around

0:09:55.150,0:09:57.007
as they naturally would.

0:09:57.007,0:09:58.436
We thought this was great.

0:09:58.436,0:10:00.311
We were really excited because it meant

0:10:00.311,0:10:02.046
that this strategy helped make

0:10:02.046,0:10:03.884
the exercise look easier,

0:10:03.884,0:10:05.424
but the big question was,

0:10:05.424,0:10:07.395
could this help make exercise

0:10:07.395,0:10:08.777
actually better?

0:10:08.777,0:10:10.226
Could it improve the quality

0:10:10.226,0:10:11.905
of exercise as well?

0:10:11.905,0:10:14.398
So next, we told our participants,

0:10:14.398,0:10:16.351
you are going to walk to the finish line

0:10:16.351,0:10:18.326
while wearing extra weight.

0:10:18.326,0:10:20.681
We added weights to their ankles

0:10:20.681,0:10:23.273
that amounted to 15 percent[br]of their body weight.

0:10:23.273,0:10:25.185
We told them to lift their knees up high

0:10:25.185,0:10:27.220
and walk to the finish line quickly.

0:10:27.220,0:10:29.606
We designed this exercise in particular

0:10:29.606,0:10:31.324
to be moderately challenging

0:10:31.324,0:10:32.987
but not impossible,

0:10:32.987,0:10:34.525
like most exercises

0:10:34.525,0:10:37.222
that actually improve our fitness.

0:10:37.222,0:10:39.526
So the big question, then:

0:10:39.526,0:10:41.663
Did keeping your eyes on the prize

0:10:41.663,0:10:43.762
and narrowly focusing on the finish line

0:10:43.762,0:10:46.731
change their experience of the exercise?

0:10:46.731,0:10:48.182
It did.

0:10:48.182,0:10:50.332
People who kept their eyes on the prize

0:10:50.332,0:10:52.368
told us afterward that it required

0:10:52.368,0:10:54.449
17 percent less exertion

0:10:54.449,0:10:56.486
for them to do this exercise

0:10:56.486,0:10:58.894
than people who looked around naturally.

0:10:58.894,0:11:01.595
It changed their subjective experience

0:11:01.595,0:11:03.371
of the exercise.

0:11:03.371,0:11:05.996
It also changed the objective nature

0:11:05.996,0:11:07.623
of their exercise.

0:11:07.623,0:11:09.846
People who kept their eyes on the prize

0:11:09.846,0:11:12.373
actually moved 23 percent faster

0:11:12.373,0:11:15.168
than people who looked around naturally.

0:11:15.446,0:11:17.504
To put that in perspective,

0:11:17.504,0:11:19.417
a 23 percent increase

0:11:19.417,0:11:23.039
is like trading in[br]your 1980 Chevy Citation

0:11:23.039,0:11:26.381
for a 1980 Chevrolet Corvette.

0:11:28.108,0:11:30.386
We were so excited by this,

0:11:30.386,0:11:32.188
because this meant that a strategy

0:11:32.188,0:11:33.946
that costs nothing,

0:11:33.946,0:11:35.984
that is easy for people to use,

0:11:35.984,0:11:37.946
regardless of whether they're in shape

0:11:37.946,0:11:39.650
or struggling to get there,

0:11:39.650,0:11:41.282
had a big effect.

0:11:41.282,0:11:42.915
Keeping your eyes on the prize

0:11:42.915,0:11:45.679
made the exercise look and feel easier

0:11:45.679,0:11:48.125
even when people were working harder

0:11:48.125,0:11:50.284
because they were moving faster.

0:11:50.284,0:11:53.257
Now, I know there's more to good health

0:11:53.257,0:11:55.313
than walking a little bit faster,

0:11:55.313,0:11:57.535
but keeping your eyes on the prize

0:11:57.535,0:11:59.223
might be one additional strategy

0:11:59.223,0:12:00.973
that you can use to help promote

0:12:00.973,0:12:03.000
a healthy lifestyle.

0:12:03.000,0:12:04.999
If you're not convinced yet

0:12:04.999,0:12:07.860
that we all see the world[br]through our own mind's eye,

0:12:07.860,0:12:09.919
let me leave you with one final example.

0:12:09.919,0:12:13.526
Here's a photograph of a beautiful street[br]in Stockholm, with two cars.

0:12:13.526,0:12:15.331
The car in the back looks much larger

0:12:15.331,0:12:16.675
than the car in the front.

0:12:16.675,0:12:18.641
However, in reality,

0:12:18.641,0:12:20.795
these cars are the same size,

0:12:20.795,0:12:23.495
but that's not how we see it.

0:12:24.095,0:12:25.446
So does this mean

0:12:25.446,0:12:27.549
that our eyes have gone haywire

0:12:27.549,0:12:29.672
and that our brains are a mess?

0:12:29.672,0:12:32.295
No, it doesn't mean that at all.

0:12:32.295,0:12:34.601
It's just how our eyes work.

0:12:34.601,0:12:37.241
We might see the world in a different way,

0:12:37.241,0:12:39.152
and sometimes that might not

0:12:39.152,0:12:41.194
line up with reality,

0:12:41.194,0:12:43.301
but it doesn't mean[br]that one of us is right

0:12:43.301,0:12:45.468
and one of us is wrong.

0:12:45.468,0:12:47.788
We all see the world[br]through our mind's eye,

0:12:47.788,0:12:50.253
but we can teach ourselves[br]to see it differently.

0:12:50.253,0:12:52.219
So I can think of days

0:12:52.219,0:12:54.418
that have gone horribly wrong for me.

0:12:54.418,0:12:56.808
I'm fed up, I'm grumpy, I'm tired,

0:12:56.808,0:12:58.697
and I'm so behind,

0:12:58.697,0:13:00.832
and there's a big black cloud

0:13:00.832,0:13:02.417
hanging over my head,

0:13:02.417,0:13:03.793
and on days like these,

0:13:03.793,0:13:05.716
it looks like everyone around me

0:13:05.716,0:13:07.653
is down in the dumps too.

0:13:07.653,0:13:09.707
My colleague at work looks annoyed

0:13:09.707,0:13:12.162
when I ask for an extension on a deadline,

0:13:12.162,0:13:14.243
and my friend looks frustrated

0:13:14.243,0:13:17.236
when I show up late for lunch[br]because a meeting ran long,

0:13:17.236,0:13:18.655
and at the end of the day,

0:13:18.655,0:13:20.522
my husband looks disappointed

0:13:20.522,0:13:23.315
because I'd rather go to bed[br]than go to the movies.

0:13:23.315,0:13:25.747
And on days like these,[br]when everybody looks

0:13:25.747,0:13:27.842
upset and angry to me,

0:13:27.842,0:13:31.242
I try to remind myself that there are[br]other ways of seeing them.

0:13:31.242,0:13:33.851
Perhaps my colleague was confused,

0:13:33.851,0:13:36.280
perhaps my friend was concerned,

0:13:36.280,0:13:39.823
and perhaps my husband[br]was feeling empathy instead.

0:13:39.823,0:13:41.728
So we all see the world

0:13:41.728,0:13:43.695
through our own mind's eye,

0:13:43.695,0:13:45.646
and on some days, it might look

0:13:45.646,0:13:47.247
like the world is a dangerous

0:13:47.247,0:13:49.576
and challenging and insurmountable place,

0:13:49.576,0:13:52.456
but it doesn't have to look[br]that way all the time.

0:13:52.456,0:13:54.807
We can teach ourselves[br]to see it differently,

0:13:54.807,0:13:57.502
and when we find a way to make the world

0:13:57.502,0:13:59.524
look nicer and easier,

0:13:59.524,0:14:01.673
it might actually become so.

0:14:01.673,0:14:03.163
Thank you.

0:14:03.163,0:14:05.455
(Applause)