Face Blindness study sheds light on typical brain function – Science Nation

Face Blindness study sheds light on typical brain function – Science Nation


[Music]
Miles O’Brien: To meet her,
you’d never know it. But, Dacia Reid
has brain damage. A car coming out
of a blind alley knocked her off her bike
when she was child. Brad Duchaine:
Face processing is especially dependent on the right temporal lobe,
and so it’s on the side here. Miles O’Brien: Dacia made a good recovery
and leads a normal life. But, she says, she long
had a nagging feeling that something was off. Dacia Reid:
It took a really long time. Just a few years ago
that I really realized I had a hard time
with facial recognition. Miles O’Brien:
It’s called “prosopagnosia,” or face blindness. With support from the National
Science Foundation, psychologist Brad Duchaine
and a team at Dartmouth College want to understand how we
recognize and process faces. To do it, they study
the brains of people who can’t. Brad Duchaine:
My main interest is trying to understand
the organization of the normal brain, and we use these brains
that have suffered brain damage to try to make inferences
about the way the normal brain operates.
Miles O’Brien: Acquired prosopagnosia
is a rare condition. Duchaine says maybe only
a few thousand people have it in all of North America. About 20 of them,
including Dacia, are coming here to his lab
to undergo a battery of tests. Marie-luise Kieseler:
You ready? Dacia Reid:
Mmm hmm. Miles O’Brien:
Like the “Famous Faces” test. Dacia Reid:
Eh! I don’t know. Dacia Reid:
Ah, I don’t know. Um, John Travolta. Marie-luise Kieseler:
Yeah, baby. Dacia Reid:
That chin. You can’t deny the chin.
(laughter) Miles O’Brien:
But they do other testing as well. Can they tell when one circle
is slightly bigger than another? Can they remember seeing
a particular scene or a certain kind of car? Brad Duchaine:
And, so imagine that we find somebody who suffered brain damage, and they can’t recognize
faces any longer, but they can still recognize
cars in the parking lot and they can recognize scenes
and things like that. What that suggests is
that faces are processed by different mechanisms
in the brain. Miles O’Brien:
And they do brain scans, MRI and functional MRI, watching which parts
of the brain are active when they see faces
or other scenes. Marie-luise Kieseler:
They are missing certain parts of the brain, or they have damaged
certain parts of the brain, and we see that on MRI scans. So, if the part is not there,
it can’t act on anything. So, we can make inferences
on what that part does. Miles O’Brien:
The ultimate goal – better understanding of
how the brain divides up tasks. Brad Duchaine:
We hope that by really developing and understanding
the face processing itself that will provide us
with a model for understanding the way other parts
of the brain work. Miles O’Brien:
Duchaine says his work won’t lead directly to any treatments
for the face blind. But Dacia still wants
to be part of it. Dacia Reid:
Well, I’m glad if they can
learn things from me. It also helped me when I found
out what my condition was because I kind of
recognized “that’s why,” you know, I don’t
recognize people because there is an issue
with the facial recognition. Miles O’Brien:
Probing the brain to understand better how our minds
process what we see. For Science Nation,
I’m Miles O’Brien.