| Identifier |
prosopagnosia_lee_novel |
| Title |
Prosopagnosia |
| Creator |
Andrew G. Lee, MD; Sowmya Yennam |
| Affiliation |
(AGL) Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, Texas; Professor of Ophthalmology, Weill Cornell Medicine, New York City, New York; (SY) Class of 2022, Baylor College of Medicine, Houston, Texas |
| Subject |
Facial Blindness |
| Description |
Summary: • Prosopagnosia is a form of facial blindness in which patients cannot recognize faces • Chief complaint: "I can't recognize faces" • Subtypes include: o Apperceptive agnosia - cannot perceive image o Associative agnosia - can see image, but cannot connect it with a person (i.e. cannot identify the image as a face) o Mirror image agnosia - cannot recognize self in the mirror (but know what the mirror is and what they should be recognizing) • Vision pathway for facial recognition: o Eye/retina > optic nerve > optic chiasm > radiations > geniculate cortex > occipital (visual) cortex o Then, visual cortex -> visual association cortex, where information is interpreted via two streams > Ventral stream to the temporal cortex = what we are looking at > Dorsal stream to the parietal cortex = where (visual-spatial/motion) • Lesion location: o Inferior occipital lobe's fusiform gyrus, where the occipital lobe and temporal lobe interact to identify a face o Bilateral lesions are the most common o Unilateral lesions tend to be right sided. |
| Transcript |
Today we're going to be talking about a very strange complaint called prosopagnosia. "Gnosia" means know - to know. "A" means not. "Prosop" is face. So, it is a form of facial blindness where patients literally cannot recognize the face of another individual and in fact sometimes can't even recognize their own face. It sounds like a crazy complaint but it's absolutely real. So, as you know the information traveling from the eye and the retina, optic nerve, chiasm, radiations through the geniculate and to the occipital cortex. That is all processing information to the visual cortex but once it leaves there, it travels to the visual association cortex. For vision. And so, when we try to interpret what we're seeing, we have both a dorsal stream and a ventral stream. The ventral stream is telling us what we're looking at, and the dorsal stream is more for spatial (visual-spatial) and motion pathways. That is the where pathway versus the what pathway. And in facial recognition, it's down here, which is the inferior occipital lobe. And that's the fusiform gyrus where the occipital lobe is talking directly to the temporal lobe to tell us whose face is this. So, that is a very specific complaint. Usually, the lesions are bilateral inferior occipital temporal but it can be unilateral. And when it is unilateral, it's usually a right-sided lesion. So, typically we're dealing with a right-sided lesion and a left homonymous hemianopsia associated with this very specific symptom: "I can't recognize faces." When they can't recognize their own face in the mirror, that's a special form of prosopagnosia which is a mirror image agnosia. They know it's a mirror, they know what a mirror is, they can tell it's not a real thing, they're not talking to the image, they're not crazy. Well, they cannot recognize their own self-image in that mirror. That's a very special type of agnosia. So, you need to know a little bit about facial blindness. It's a very specific complaint, it localizes to the inferior portion of the occipital temporal region, and it's usually a bilateral lesion but it can be a right-sided lesion. And so, in any patient who has a left homonymous hemianopsia, even if their acuity is 20/20, if you hear that complaint, "I can't see people's faces and recognize them", you should be thinking about prosopagnosia. In the prosopagnosia people, they can tell who it is as soon as the person starts talking. So, they know who the person is. And the two types aperceptive and associative agnosia. The aperceptive cannot even perceive the image. The associative can see something but they can't tell who it is; so, they're having a problem connecting the person's name, their backstory, with that particular face. Both the apperceptive and the associative agnosias of facial recognition are called prosopagnosia. |
| Date |
2021-04 |
| Language |
eng |
| Format |
video/mp4 |
| Type |
Image/MovingImage |
| Collection |
Neuro-Ophthalmology Virtual Education Library: Andrew G. Lee Collection: https://novel.utah.edu/Lee/ |
| Publisher |
North American Neuro-Ophthalmology Society |
| Holding Institution |
Spencer S. Eccles Health Sciences Library, University of Utah |
| Rights Management |
Copyright 2019. For further information regarding the rights to this collection, please visit: https://NOVEL.utah.edu/about/copyright |
| ARK |
ark:/87278/s6x987v4 |
| Setname |
ehsl_novel_lee |
| ID |
1680620 |
| Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6x987v4 |
