What happens in your brain when you taste food
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0:01 - 0:04So I had this very interesting experience
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0:04 - 0:05five years ago.
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0:06 - 0:09You know, me and my husband,
we were out grocery shopping, -
0:09 - 0:11as we do every other day,
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0:11 - 0:14but this time, we found this fancy,
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0:14 - 0:18you know, I'm talking fair-trade,
I'm talking organic, -
0:18 - 0:20I'm talking Kenyan, single-origin coffee
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0:20 - 0:22that we splurged and got.
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0:23 - 0:27And that was when the problem
started already. -
0:27 - 0:30You know, my husband,
he deemed this coffee blend superior -
0:30 - 0:33to our regular and much cheaper coffee,
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0:33 - 0:37which made me imagine a life
based solely on fancy coffee -
0:37 - 0:40and I saw our household budget explode.
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0:40 - 0:41(Laughter)
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0:41 - 0:42And worse ...
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0:43 - 0:46I also feared that this investment
would be in vain. -
0:46 - 0:50That we wouldn't be able to notice
this difference after all. -
0:51 - 0:55Unfortunately, especially for my husband,
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0:55 - 0:58he had momentarily forgotten
that he's married to a neuroscientist -
0:58 - 1:00with a specialty in food science.
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1:00 - 1:01(Laughter)
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1:01 - 1:03Alright?
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1:03 - 1:04So without further ado,
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1:04 - 1:06I mean, I just put him to the test.
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1:07 - 1:09I set up an experiment
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1:09 - 1:12where I first blindfolded my husband.
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1:12 - 1:14(Laughter)
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1:14 - 1:17Then I brewed the two types of coffee
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1:17 - 1:20and I told him that
I would serve them to him -
1:20 - 1:21one at a time.
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1:22 - 1:24Now, with clear certainty,
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1:24 - 1:27my husband, he described
the first cup of coffee -
1:27 - 1:28as more raw and bitter.
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1:28 - 1:31You know, a coffee
that would be ideal for the mornings -
1:31 - 1:35with the sole purpose of terrorizing
the body awake by its alarming taste. -
1:35 - 1:37(Laughter)
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1:37 - 1:40The second cup of coffee,
on the other hand, -
1:40 - 1:44was both fruity and delightful.
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1:44 - 1:48You know, coffee that one
can enjoy in the evening and relax. -
1:49 - 1:52Little did my husband know, however,
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1:52 - 1:56that I hadn't actually given him
the two types of coffee. -
1:56 - 1:59I had given him the exact same
cup of coffee twice. -
1:59 - 2:01(Laughter)
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2:01 - 2:04And obviously, it wasn't
this one cup of coffee -
2:04 - 2:07that had suddenly gone
from horrible to fantastic. -
2:07 - 2:11No, this taste difference
was a product of my husband's own mind. -
2:12 - 2:15Of his bias in favor of the fancy coffee
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2:15 - 2:18that made him experience taste differences
that just weren't there. -
2:20 - 2:24Alright, so, having saved
our household budget, -
2:24 - 2:26and finishing on a very good laugh,
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2:26 - 2:27me especially --
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2:27 - 2:28(Laughter)
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2:28 - 2:31I then started wondering
just how we could have received -
2:31 - 2:35two such different responses
from a single cup of coffee. -
2:35 - 2:39Why would my husband
make such a bold statement -
2:39 - 2:43at the risk of being publicly mocked
for the rest of his life? -
2:44 - 2:45(Laughter)
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2:47 - 2:51The striking answer is
that I think you would have done the same. -
2:51 - 2:54And that's the biggest challenge
in my field of science, -
2:54 - 2:58assessing what's reality
behind these answers -
2:58 - 2:59that we receive.
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2:59 - 3:02Because how are we
going to make food tastier -
3:02 - 3:05if we cannot rely on what people
actually say they like? -
3:07 - 3:10To understand, let's first have a look
at how we actually sense food. -
3:11 - 3:13When I drink a cup of coffee,
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3:13 - 3:17I detect this cup of coffee
by receptors on my body, -
3:17 - 3:22information which is then turned
into activated neurons in my brain. -
3:23 - 3:25Wavelengths of light
are converted to colors. -
3:25 - 3:29Molecules in the liquid
are detected by receptors in my mouth, -
3:29 - 3:33and categorized as one
of five basic tastes. -
3:33 - 3:37That's salty, sour,
bitter, sweet and umami. -
3:38 - 3:42Molecules in the air
are detected by receptors in my nose -
3:42 - 3:43and converted to odors.
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3:44 - 3:48And ditto for touch, for temperature,
for sound and more. -
3:48 - 3:52All this information is detected
by my receptors -
3:52 - 3:56and converted into signals
between neurons in my brain. -
3:56 - 4:00Information which is then
woven together and integrated, -
4:00 - 4:03so that my brain recognizes
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4:03 - 4:09that yes, I just had a cup of coffee,
and yes, I liked it. -
4:10 - 4:12And only then,
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4:12 - 4:15after all this neuron heavy lifting,
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4:15 - 4:18do we consciously experience
this cup of coffee. -
4:19 - 4:23And this is now where we have
a very common misconception. -
4:23 - 4:27People tend to think
that what we experience consciously -
4:27 - 4:30must then be an absolute
true reflection of reality. -
4:31 - 4:32But as you just heard,
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4:32 - 4:36there are many stages
of neural interpretation -
4:36 - 4:40in between the physical item
and the conscious experience of it. -
4:40 - 4:43Which means that sometimes,
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4:43 - 4:46this conscious experience is not really
reflecting that reality at all. -
4:47 - 4:49Like what happened to my husband.
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4:50 - 4:54That's because some physical stimuli
may just be so weak -
4:54 - 4:58that they just can't break that barrier
to enter our conscious mind, -
4:58 - 5:00while the information that does
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5:00 - 5:04may get twisted on its way there
by our hidden biases. -
5:05 - 5:09And people, they have a lot of biases.
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5:12 - 5:14Yes, if you're sitting there
right now, thinking ... -
5:16 - 5:19you could probably have done
better than my husband, -
5:19 - 5:22you could probably have assessed
those coffees correctly, -
5:22 - 5:25then you're actually
suffering from a bias. -
5:26 - 5:29A bias called the bias blind spot.
-
5:29 - 5:33Our tendency to see ourselves
as less biased than other people. -
5:34 - 5:35(Laughter)
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5:35 - 5:36And yeah, we can even be biased
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5:36 - 5:38about the biases that we're biased about.
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5:38 - 5:39(Laughter)
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5:39 - 5:42Not trying to make this any easier.
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5:42 - 5:47A bias that we know in the food industry
is the courtesy bias. -
5:48 - 5:50This is a bias where we give an opinion
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5:50 - 5:54which is considered socially acceptable,
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5:54 - 5:56but it's certainly not
our own opinion, right? -
5:58 - 6:00And I'm challenged by this
as a food researcher, -
6:00 - 6:05because when people say they like
my new sugar-reduced milkshake, -
6:05 - 6:06do they now?
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6:06 - 6:08(Laughter)
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6:08 - 6:10Or are they saying they like it
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6:10 - 6:13because they know I'm listening
and they want to please me? -
6:14 - 6:17Or maybe they just to seem
fit and healthy in my ears. -
6:18 - 6:20I wouldn't know.
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6:20 - 6:24But worse, they wouldn't
even know themselves. -
6:25 - 6:27Even trained food assessors,
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6:27 - 6:29and that's people who have been
explicitly taught -
6:29 - 6:33to disentangle the sense of smell
and the sense of taste, -
6:33 - 6:37may still be biased
to evaluate products sweeter -
6:37 - 6:38if they contain vanilla.
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6:38 - 6:40Why?
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6:40 - 6:43Well, it's certainly not
because vanilla actually tastes sweet. -
6:45 - 6:48It's because even these
professionals are human, -
6:48 - 6:52and have eaten lot of desserts, like us,
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6:52 - 6:55and have therefore learned to associate
sweetness and vanilla. -
6:56 - 6:59So taste and smell
and other sensory information -
6:59 - 7:02is inextricably entangled
in our conscious mind. -
7:03 - 7:05So on one hand, we can actually use this.
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7:05 - 7:08We can use these conscious experiences,
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7:08 - 7:12use this data, exploit it
by adding vanilla instead of sugar -
7:12 - 7:14to sweeten our products.
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7:15 - 7:17But on the other hand,
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7:17 - 7:19with these conscious evaluations,
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7:19 - 7:20I still wouldn't know
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7:20 - 7:23whether people actually liked
that sugar-reduced milkshake. -
7:24 - 7:26So how do we get around this problem?
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7:26 - 7:28How do we actually assess what's reality
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7:28 - 7:31behind these conscious food evaluations?
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7:31 - 7:35The key is to remove the barrier
of the conscious mind -
7:35 - 7:38and instead target the information
in the brain directly. -
7:39 - 7:40And it turns out
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7:40 - 7:43our brain holds a lot
of fascinating secrets. -
7:44 - 7:49Our brain constantly receives
sensory information from our entire body, -
7:49 - 7:51most of which we don't even
become aware of, -
7:51 - 7:54like the taste information
that I constantly receive -
7:54 - 7:56from my gastrointestinal tract.
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7:57 - 8:01And my brain will also act
on all this sensory information. -
8:01 - 8:05It will alter my behavior
without my knowledge, -
8:05 - 8:08and it can increase
the diameter of my pupils -
8:08 - 8:10if I experience something I really like.
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8:10 - 8:13And increase my sweat production
ever so slightly -
8:13 - 8:15if that emotion was intense.
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8:16 - 8:18And with brain scans,
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8:18 - 8:21we can now assess
this information in the brain. -
8:22 - 8:24Specifically, I have used
a brain-scanning technique -
8:24 - 8:27called electroencephalography,
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8:27 - 8:29or "EEG" in short,
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8:29 - 8:33which involves wearing a cap
studded with electrodes, -
8:33 - 8:35128 in my case.
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8:36 - 8:40Each electrode then measures
the electrical activity of the brain -
8:40 - 8:42with precision down to the millisecond.
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8:44 - 8:46The problem is, however,
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8:46 - 8:48it's not just the brain
that's electrically active, -
8:48 - 8:51it's also the rest of the body
as well as the environment -
8:51 - 8:54that contains a lot
of electrical activity all the time. -
8:54 - 8:55To do my research,
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8:55 - 8:58I therefore need
to minimize all this noise. -
8:58 - 9:02So I ask my participants
to do a number of things here. -
9:02 - 9:04First off,
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9:04 - 9:07I ask them to rest their head
in a chin rest, -
9:07 - 9:09to avoid too much muscle movement.
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9:09 - 9:13I also ask them to, meanwhile,
stare at the center of a computer monitor -
9:13 - 9:16to avoid too much
eye movements and eye blinks. -
9:16 - 9:19And I can't even have swallowing,
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9:19 - 9:23so I ask my participants
to stick the tongue out of their mouth -
9:23 - 9:25over a glass bowl,
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9:25 - 9:30and then I constantly let
taste stimuli onto the tongue, -
9:30 - 9:32which then drip off into this bowl.
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9:32 - 9:33(Laughter)
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9:33 - 9:37And then, just to complete
this wonderful picture, -
9:37 - 9:40I also provide my participants with a bib,
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9:40 - 9:43available in either pink
or blue, as they please. -
9:43 - 9:47(Laughter)
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9:47 - 9:49Looks like a normal
eating experience, right? -
9:49 - 9:51(Laughter)
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9:52 - 9:53No, obviously not.
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9:55 - 9:56And worse,
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9:56 - 9:59I can't even control
what my participants are thinking about, -
9:59 - 10:01so I need to repeat this taste procedure
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10:01 - 10:03multiple times.
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10:03 - 10:06Maybe the first time,
they're thinking about the free lunch -
10:06 - 10:08that I provide for participating,
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10:08 - 10:11or maybe the second time,
they're thinking about Christmas coming up -
10:11 - 10:14and what to get for Mom
this year, you know. -
10:15 - 10:19But common for each response
is the response to the taste. -
10:19 - 10:23So I repeat this taste
procedure multiple times. -
10:23 - 10:25Sixty, in fact.
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10:25 - 10:27And then I average the responses,
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10:27 - 10:30because responses unrelated
to taste will average out. -
10:30 - 10:32And using this method,
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10:32 - 10:35we and other labs,
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10:35 - 10:38have investigated how long a time
it takes from "food lands on our tongue" -
10:38 - 10:41until our brain has figured out
which taste it's experiencing. -
10:42 - 10:45Turns out this occurs within the first
already 100 milliseconds, -
10:45 - 10:48that's about half a second
before we even become aware of it. -
10:48 - 10:50And next up, we also investigated
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10:50 - 10:54the taste difference between sugar
and artificial sweeteners -
10:54 - 10:56that in our setup taste extremely similar.
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10:57 - 10:59In fact, they tasted so similar
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10:59 - 11:02that half my participants
could only barely tell the taste apart, -
11:02 - 11:05while the other half simply couldn't.
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11:05 - 11:07But amazingly,
-
11:07 - 11:10if we looked across
the entire group of participants, -
11:10 - 11:14we saw that their brains
definitely could tell the taste apart. -
11:15 - 11:18So with EEG and other
brain-scanning devices -
11:18 - 11:20and other physiological measures --
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11:20 - 11:21sweat and pupil size --
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11:21 - 11:23we have new gateways to our brain.
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11:24 - 11:27Gateways that will help us
remove the barrier of the conscious mind -
11:27 - 11:30to see through the biases of people
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11:30 - 11:32and possibly even capture
subconscious taste differences. -
11:33 - 11:37And that's because we can now measure
people's very first response to food -
11:37 - 11:39before they've become conscious of it,
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11:39 - 11:42and before they've started rationalizing
why they like it or not. -
11:42 - 11:45We can measure people's
facial expressions, -
11:45 - 11:47we can measure where they're looking,
-
11:47 - 11:49we can measure their sweat response,
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11:49 - 11:52we can measure their brain response.
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11:52 - 11:54And with all these measures,
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11:54 - 11:56we are going to be able
to create tastier foods, -
11:56 - 11:59because we can measure
whether people actually like -
11:59 - 12:01that sugar-reduced milkshake.
-
12:01 - 12:05And we can create healthier foods
without compromising taste, -
12:05 - 12:08because we can measure the response
to different sweeteners -
12:08 - 12:11and find the sweetener that gives
the response that's more similar -
12:11 - 12:12to the response from sugar.
-
12:12 - 12:15And furthermore, we can just help
create healthier foods, -
12:15 - 12:18because we can help understand
how we actually sense food -
12:18 - 12:19in the first place.
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12:20 - 12:22Which we know surprisingly little about.
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12:23 - 12:26For example, we know
that there are those five basic tastes, -
12:26 - 12:28but we strongly suspect
that there are more, -
12:28 - 12:33and in fact, using our EEG setup,
we found evidence that fat, -
12:33 - 12:36besides being sensed
by its texture and smell, -
12:36 - 12:37is also tasted.
-
12:38 - 12:41Meaning that fat could be
this new sixth basic taste. -
12:42 - 12:46And if we figure out
how our brain recognizes fat and sugar, -
12:46 - 12:47and I'm just dreaming here,
-
12:47 - 12:49but could we then one day
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12:49 - 12:53create a milkshake with zero calories
that tastes just like the real deal? -
12:55 - 12:57Or maybe we figure out that we can't,
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12:57 - 13:00because we subconsciously detect calories
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13:00 - 13:03via our receptors
in our gastrointestinal tract. -
13:03 - 13:05The future will show.
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13:06 - 13:09Our conscious experience of food
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13:09 - 13:14is just the tip of the iceberg
of our total sensation of food. -
13:14 - 13:16And by studying this total sensation,
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13:16 - 13:19conscious and subconscious alike,
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13:19 - 13:24I truly believe that we can make
tastier and healthier foods for all. -
13:24 - 13:25Thank you.
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13:25 - 13:30(Applause)
- Title:
- What happens in your brain when you taste food
- Speaker:
- Camilla Arndal Andersen
- Description:
-
With fascinating research and hilarious anecdotes, neuroscientist Camilla Arndal Andersen takes us into the lab where she studies people's sense of taste via brain scans. She reveals surprising insights about the way our brains subconsciously experience food -- and shows how this data could help us eat healthier without sacrificing taste.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 13:43
Oliver Friedman edited English subtitles for What happens in your brain when you taste food | ||
Oliver Friedman approved English subtitles for What happens in your brain when you taste food | ||
Oliver Friedman edited English subtitles for What happens in your brain when you taste food | ||
Krystian Aparta accepted English subtitles for What happens in your brain when you taste food | ||
Krystian Aparta edited English subtitles for What happens in your brain when you taste food | ||
Krystian Aparta edited English subtitles for What happens in your brain when you taste food | ||
Krystian Aparta edited English subtitles for What happens in your brain when you taste food | ||
Krystian Aparta edited English subtitles for What happens in your brain when you taste food |