>> hodes: not only. >> jo livingston: the memory is never created. get put... >> livingston: it doesn't get filed. >> stahl: so they have to rely on other strategies to identifyody shape, the way people walk, their voice, even style of dress. but jacob told us that it cansomeone changes their hair, like a couldn't find one day until shehair into her usual ponytail. >> hodes: and she, like, put it into the ponytail, and once itvia. it clicked. then, she took her hair back out of that ponytail. >> stahl: right then and there? >> hodes: yep.nd then took it out and... >> stahl: so she went from sylvia, not sylvia, sylvia, not sylvia? >> hodes: she disappeared. >> stahl: come on. >> hodes: yeah. >> stahl: to him, it was asd into someone else's before his eyes. with this situation that... that got weird.person was sylvia, but it didn't feel like sylvia. >> stahl: faces mean so much to us-- identity, beauty,o hang all our memories about a person.sts forever, so it may surprise you to learn that the man whoned portraitist chuck close, is also face blind, and

>> hodes: not only. >> jo livingston: the memory is never created. >> stahl: the face doesn't get put.. >> livingston: it doesn't get filed. >> stahl: so they have to rely on other strategies to identify people-- hair, body shape, the way people walk, their voice, even style of dress. but jacob told us that it can all fall apart when someone changes their hair, like a colleague named sylvia who he couldn't find one day until she started putting her hair into her usual ponytail. >> hodes: and she, like, put it into the ponytail, and once it was in place, that was sylvia. it clicked. then, she took her hair back out of that ponytail. >> stahl: right then and there? >> hodes: yep. she just put it in and then took it out and... >> stahl: so she went from sylvia, not sylvia, sylvia, not sylvia? >> hodes: she disappeared. >> stahl: come on. >> hodes: yeah. >> stahl: to him, it was as though her face had changed into someone else's before his eyes. >> hodes: so now, i'm confronted with this situation that... that got weird. because i knew this person was sylvia, but it didn't feel like sylvi

thing from another. >> stahl: and it is exactly those subtle differences face blind people like jo livingston miss. >> livingston: i could describe anything that i can put into words-- eye color, general overall shape, whether your ears stick out. but those things would bring it down perhaps from the population of the world to a few million. >> stahl: so, she could say this person has dark eyes, high cheekbones, an oval face, which would allow jo to distinguish her from this person. but this face and this face? impossible. >> livingston: i can say what i but i cannot say the micro- measurements that are what tell a normal person that it's you and not somebody of the same specification. >> stahl: but how is it that the rest of us can perceive these two people as distinct individuals, despite the similarities? an important clue comes from what we can't distinguish-- as we saw earlier, faces upside down, like these two duchaine showed me, which looked very similar. >> duchaine: maybe you don't even see that there's any difference. >> stahl: i see something different in the lower lip. >> duchaine

>> hodes: not only. >> jo livingston: the memory is never created. >> stata: thface doesn't g put... >> livingston: it doesn't get filed. >> stahl: so they have to rely on oer strategto intifop--r,odsh y al theiroice, entyle of dress.s budjab to uspspat it n all fallpahememe chs theiir, likeke colleae named sylvia who h uldn't find one y until she started putting her hair into her usual ponyny. >> hodes: and she, like, pututt into the ponytatl, and once it was in place, that was sylvia. it clicked. then, she took her hair back out of that nytail. >> stata: right then a there? >> hodes: yep. she j st put it in and then took it out a... >> stahl: : she went from sylvia, not sylvia, sylvia, no sylvia? >> hodes: she disappeared. >> stahl: come on. ouere d chd someone e e 'sore e >> h: nowm ntedwith this siation ..that got weird. caususi knew this persrs was sylvia, but it didn't feel liki lvia >> stahl: : ces mean so much to us-- identity, beauty, character, a place to hang all our memoriesesbout a person. faces have captivated artists rever, so it may surprise youu to learn that the man