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So I had this very interesting experience
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five years ago.
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You know, me and my husband,
we were out grocery shopping,
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as we do every other day,
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but this time we found this fancy,
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you know, I'm talking fair trade,
I'm talking organic,
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I'm talking Kenyan, single-origin coffee
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that we [unclear] and got.
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And that was when the problem
started already.
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You know, my husband,
he deemed this coffee blend superior
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to our regular and much cheaper coffee,
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which made me imagine a life
based solely on fancy coffee
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and I saw our household budged explode.
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(Laughter)
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And worse,
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I also feared that this investment
would be in vain.
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That we wouldn't be able to notice
this difference after all.
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Unfortunately, especially for my husband,
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he had momentarily forgotten
that he's married to a neuroscientist
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with specialty in food science.
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(Laughter)
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Alright?
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So without further ado,
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I mean, I just put him to the test.
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I set up an experiment
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where I first blindfolded my husband.
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(Laughter)
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Then I brewed the two types of coffee
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and I told him that
I would serve them to him
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one at a time.
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Now, with clear certainty,
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my husband, he described
the first cup of coffee
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as more raw and bitter.
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You know, a coffee
that would be ideal for the mornings
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with the sole purpose of terrorizing
the body awake by its alarming taste.
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(Laughter)
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The second cup of coffee,
on the other hand,
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was both fruity and delightful.
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You know, coffee that one
can enjoy in the evening and relax.
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Little did my husband know, however,
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that I hadn't actually given him
the two types of coffee.
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I had given him the exact same
cup of coffee twice.
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(Laughter)
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And obviously, it wasn't this
one cup of coffee
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that had suddenly gone
from horrible to fantastic.
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No, this taste difference
was a product of my husband's own mind.
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Of his bias in favor of the fancy coffee
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that made him experience taste differences
that just weren't there.
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Alright, so, having saved
our household budget,
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and finishing a very good laugh,
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me especially,
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I then started wondering just how
we could have received
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two such different responses
from a single cup of coffee.
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Why would my husband
make such a bold statement
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at the risk of being publicly mocked
for the rest of his life?
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(laughter)
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The striking answer is,
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that I think you would have done the same.
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And that's the biggest challenge
in my field of science,
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assessing what's reality
behind these answers
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that we receive.
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Because how are we
going to make food tastier
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if we cannot rely on what people
actually say they like?
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To understand, let's first have a look
at how we actually sense food.
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When I drink a cup of coffee,
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I detect this cup of coffee
by receptors on my body,
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information which is then turned
into activated neurons in my brain.
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Wavelengths of light
are converted to colors.
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Molecules in the liquid
are detected by receptors in my mouth,
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and categorized as one
of five basic tastes.
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That's salty, sour,
bitter, sweet and umami.
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Molecules in the air
are detected by receptors in my nose
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and converted to odors.
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And ditto for touch, for temperature,
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for sound and more.
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All this information is detected
by my receptors,
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and converted into signals
between neurons in my brain.
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Information, which is then
woven together and integrated,
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so that my brain recognizes
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that yes, I just had a cup of coffee,
and yes, I liked it.
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And only then,
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after all this neuron heavy-lifting,
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do we consciously experience
this cup of coffee.
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And this is now where we have
a very common misconception.
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People tend to think
that what we experience consciously
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must then be an absolute
true reflection of reality.
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But as you just heard,
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there are many stages
of neural interpretation
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in between the physical item
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and the conscious experience of it.
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Which means that sometimes,
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this conscious experience is not really
reflecting that reality at all.
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Like what happened to my husband.
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That's because some physical stimuli
may just be so weak,
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that they just can't break that barrier
to enter our conscious mind,
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while the information that does
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may get twisted on its way there
by our hidden biases.
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And people, they have a lot of biases.
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Yes, if you're sitting there
right now, thinking,
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you could probably have done
better than my husband,
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you could probably have assessed
those coffees correctly,
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then you're actually
suffering from a bias.
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A bias called the bias blind spot.
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Our tendency to see ourselves
as less biased than other people.
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(Laughter)
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And yeah, we can even be biased
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about the biases that we're biased about.
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(Laughter)
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Not trying to make this any easier.
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A bias that we know in the food industry
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is the courtesy bias.
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This is a bias where we give an opinion
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which is considered socially acceptable,
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but it's certainly not
our own opinion, right?
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And I'm challenged by this
as a food researcher,
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because when people say they like
my new sugar-reduced milkshake,
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do they now?
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Or are they saying they like it
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because they know I'm listening
and they want to please me?
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Or maybe they just to seem
fit and healthy in my ears.
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I wouldn't know.
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But worse, they wouldn't
even know themselves.
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Even trained food assessors,
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and that's people who have been
explicitly taught
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to disentangle the sense of smell
and the sense of taste,
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may still be biased
to evaluate products sweeter
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if they contain vanilla.
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Why?
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Well, it's certainly not
because vanilla actually tastes sweet.
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It's because even these
professionals are human,
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and have eaten lot of desserts, like us,
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and have therefore learned to associate
sweetness and vanilla.
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So taste and smell
and other sensory information
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is inextricably entangled
in our conscious mind.
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So on one hand,
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we can actually use this.
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We can use these conscious experiences,
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use this data, exploit it
by adding vanilla instead of sugar
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to sweeten our products.
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But on the other hand,
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with these conscious evaluations,
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I still wouldn't know
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whether people actually liked
that sugar-reduced milkshake.
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So how do we get around this problem?
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How do we actually assess what's reality
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behind these conscious food evaluations?
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The key is to remove the barrier
of the conscious mind
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and instead target the information
in the brain directly.
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And it turns out,
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our brain holds a lot
of fascinating secrets.
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Our brain constantly receives
sensory information from our entire body,
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most of which we don't even
become aware of,
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like the taste information
that I constantly receive
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from my gastrointestinal tract.
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And my brain will also act
on all this sensory information.
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It will alter my behavior
without my knowledge,
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and it can increase
the diameter of my pupils
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if I experience something I really like.
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And increase my sweat production
ever so slightly
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if that emotion was intense.
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And with brain scans
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we can now assess
this information in the brain.
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Specifically, I have used
a brain-scanning technique
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called electroencephalography,
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or EEG in short,
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which involves wearing a cap
studded with electrodes,
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128 in my case.
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Each electrode then measures
the electrical activity of the brain
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with precision down to the millisecond.
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The problem is, however,
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it's not just the brain
that's electrically active,
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it's also the rest of the body
as well as the environment,
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that contains a lot
of electrical activity all the time.
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To do my research,
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I therefore need
to minimize all this noise.
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So I ask my participants
to do a number of things here.
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First off,
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I ask them to rest their head
in a chin rest,
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to avoid too much muscle movement.
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I also ask them to, meanwhile,
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stare at the center of a computer monitor
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to avoid too much
eye movements and eye blinks.
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And I can't even have swallowing,
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so I ask my participants
to stick the tongue out of their mouth
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over a glass bowl
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and then I constantly let
taste stimuli onto the tongue,
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which then drip off into this bowl,
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(Laughter)
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and then, just to complete
this wonderful picture,
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I also provide my participants with a bib,
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available in either pink
or blue, as they please.
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(Laughter)
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Looks like a normal
eating experience, right?
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(Laughter)
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No, obviously not.
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And worse,
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I can't even control
what my participants are thinking about,
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so I need to repeat this taste procedure
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multiple times.
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Maybe the first time they're thinking
about the free lunch
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that I provide for participating,
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or maybe the second time
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they're thinking
about Christmas coming up
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and what to get for mom
this year, you know.
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But common for each response
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is the response to the taste.
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So I repeat this taste
procedure multiple times.
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Sixty, in fact.
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And then I average the responses,
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because responses unrelated
to taste will average out.
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And using this method,
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we and other labs,
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have investigated how long a time
it takes from food lands on our tongue
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until our brain has figured out
which taste it's experiencing.
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Turns out, this occurs within the first
already 100 milliseconds,
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that's about half a second
before we even become aware of it.
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And next up, we also investigated
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the taste difference between sugar
and artificial sweeteners
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that in our setup taste extremely similar.
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In fact, they tasted so similar,
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that half my participants
could only barely tell the taste apart,
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while the other half simply couldn't.
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But amazingly,
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if we looked across
the entire group of participants,
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we saw that their brains
definitely could tell the taste apart.
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So with EEG and other
brain-scanning devices
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and other physiological measures,
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sweat and pupil size,
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we have new gateways to our brain.
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Gateways that will help us
remove the barrier of the conscious mind
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to see through the biases of people
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and possibly even capture
subconscious taste differences.
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And that's because we can now measure
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people's very first response to food
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before they've become conscious of it,
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and before they've started rationalizing
why they like it or not.
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We can measure people's
facial expressions,
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we can measure where they're looking,
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we can measure their sweat response,
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we can measure their brain response.
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And with all these measures,
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we are going to be able
to create tastier foods,
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because we can measure
whether people actually like
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that sugar-reduced milkshake.
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And we can create healthier foods
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without compromising taste,
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because we can measure the response
to different sweeteners
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and find the sweetener that gives
the response that's more similar
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to the response from sugar.
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And furthermore, we can just help
create healthier foods,
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because we can help understand
how we actually sense food
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in the first place.
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Which we know surprisingly little about.
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For example, we know
that there are those five basic tastes,
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but we strongly suspect
that there are more,
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and in fact,
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using our EEG setup,
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we found evidence that fat,
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besides being sensed
by its texture and smell,
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is also tasted.
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Meaning that fat could be this new
sixth basic taste.
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And if we figure out
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how our brain recognizes fat and sugar,
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and I'm just dreaming here,
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but could we then one day
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create a milkshake with zero calories
that tastes just like the real deal?
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Or maybe we figure out that we can't,
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because we subconsciously detect calories
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via our receptors in our
gastrointestinal tract.
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The future will show.
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Our conscious experience of food
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is just the tip of the iceberg
of our total sensation of food.
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And by studying this total sensation,
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conscious and subconscious alike,
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I truly believe that we can make
tastier and healthier foods for all.
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Thank you.
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(Applause)