Episode Transcript
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Speaker 1 (00:01):
Welcome to brain Stuff production of I Heart Radio, Hey
brain Stuff, Lauren bob o blam here. The world is
full of faces. Faces in wall outlets, faces in lamp switches,
faces in cheese graters. Sometimes these faces have religious significance,
or like the woman who found an image of the
Virgin Mary and her grilled cheese, or the cheeto that
(00:24):
looks convincingly like Jesus. The phenomenon of seeing faces where
they're not supposed to be, in clouds, on buildings in
tacos is so common and widespread that it has a
name paraidolia. In Greek, paraidolia translates as beyond form or image,
and it means finding meanings or patterns where there aren't any,
(00:46):
like hearing a heartbeat in white noise, or believing that
a seat cushion is mad at you. It's easy to
dismiss paraidolia as at best of fun optical illusion or
at worst a psychotic delusion. But some scientists now believe
that our uncanny ability to find faces and everyday objects
points to a new understanding of how our brains process
(01:08):
the outside world. Instead of taking in visual cues and
then making sense of them. As an apple, a tree
or a face. It might be the other way around.
What if our brains are actually telling our eyes what
to see. We spoke with Kang Lee, a professor of
applied psychology and human development at the University of Toronto.
(01:30):
Lee has spent decades studying how infants, children and adults
process faces, and relatedly, he gave a popular Ted talk
on how to tell kids are lying. Lee explained that
we're basically programmed to see faces as a product of
millions of years of evolution. Quote as soon as we're born,
we start to look for faces. One reason is that
(01:52):
our ancestors needed to avoid predators or find prey, all
of which have faces. And a second reason is that
humans are very social animals. When we interact with each other,
we need to know if the other person is a
friend or foe. Since the ability to quickly recognize and
respond to different faces could be a matter of life
(02:13):
and death. There's a much higher cost for not seeing
the lions face in the underbrush than for mistaking an
orange and black flower for a lion's face. The brain
is better off making a false positive if it means
that you're primed to recognize real danger too. Okay, So
if evolution has programmed our brains to prioritize faces, how
(02:36):
exactly does it all play out under the hood. The
conventional understanding of how we see things is that the
eyes taken visual stimuli from the outside world a light, colors,
shapes movement, and send that information to the visual cortex,
located in a region of the brain known as the
occipital lobe. After the occipital lobe translates the raw data
(02:57):
into images, those images are sent to the frontal lobe,
which does the high level processing. We look at a cliff,
and our brains then have to determine is that a
rock outcropping or is it a giant head. That conventional
model is what Lee calls bottom up processing, in which
the brain's role is to passively take an information and
(03:19):
make sense of it. If the brain sees faces everywhere,
it's because the brain is responding to face like stimuli,
basically any cluster of spots and spaces that roughly look
like two eyes, a nose, and amount. But Lee and
other researchers began to question the bottom up of processing model.
They wondered if it wasn't the other way around, a
(03:41):
top down process In which the brain is calling the shots.
Alice said, we wanted to know whether the frontal lobe
actually plays a very important role in helping us to
see faces instead of the face imagery coming from the outside.
The brain generates some kind of expectation from the frontal lobe,
then goes back to the occipital lobe and finally to
(04:03):
our eyes, and then we see faces. That question is
what made Lee think about paradolia. Had read those stories
of people seeing images of Jesus, Elvis, and angels in
their toast and tortillas and wondered if he could build
an experiment around it. So Lee recruited a bunch of
(04:24):
regular people, hooked them up to an fm R I scanner,
and showed them a series of grainy images, some of
which contained hidden faces and some of which were pure noise.
The participants were told that exactly half of the images
contained a face, which was not true, and we're asked
with each new image, do you see a face? As
(04:45):
a result of this prodding, participants reported seeing a face
thirty four percent of the time, and there was nothing
but static. What was most interesting to Lee were the
images coming back from the real time f m R
I scan. When part disipants reported seeing a face, the
face area of their visual cortex lit up even when
(05:05):
there was no face in the image at all. That
told Lee then another part of the brain must be
telling the visual cortex to see a face. In a
paper provocatively titled seeing Jesus in Toast Neural and Behavioral
Correlates a Face Paraidolia, Lee and his colleagues reported that
when the brain was properly primed to see faces, then
(05:27):
the expectation to see a face was coming from the
frontal lobe, specifically an area called the inferior frontal gyrus.
Lee explained, the inferior frontal gyrus is a very interesting area.
It's related to generating some kind of idea and an
instructing our visual cortex to see things. If the idea
is a face, then it would see a face. If
(05:49):
the idea is Jesus, I'm pretty sure the cortex is
going to see Jesus. If the idea is Elvis, then
it's going to see Elvis. The Jesus in Toast paper
one Lee teen ig Noble Prize, a cheeky award handed
out by the humorous science magazine Annals of improbable research,
but Lie says the Paradolia experiment proved the top down
(06:11):
processing plays a critical role in how we experience the
world around us. He said, a lot of things we
see in the world aren't coming from our site, but
are coming from inside our minds. Lee has also run
research on babies and racial bias. He found that the
very youngest babies were able to recognize differences between faces
(06:31):
of all races, but lost that ability as they grew older.
By nine months, they could only differentiate between faces that
were their same race. The rest started to blur together.
The reason is that they had only been exposed to
same race faces, in most case mom and dad, for
the first nine months of their life. From his research,
(06:53):
Lee now believes that racial biases are not biological. We
simply learned to trust people that look like the faces
we saw when our brains were first developing. Unfortunately, this
can develop later into different kinds of biases based on
societal messaging and stereotypes. Lee said. The reason that there
are racial biases is because of early experiences. If we
(07:16):
created a diverse visual and social experience for children, then
they would be less likely to have biases. The good
news is that parents and educators can combat racial bias
by exposing infants and toddlers to faces of all races
and identifying them by things like names, professions, or other
personally identifying qualifiers or interests, not as a white person
(07:40):
or a black person. Today's episode was written by Dave
Ruse and produced by Tyler Clain. For more on this
amounts of other topics, visit how stuff works dot com.
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