Prosopagnosia Flashcards
Prosopagnosia is also called ..
face blindness
Prosopagnosia, also called face blindness, is a ..
..a cognitive disorder of face perception in which the ability to recognize familiar faces, including one’s own face (self-recognition), is impaired, while other aspects of visual processing (e.g., object discrimination) and intellectual functioning (e.g., decision- making) remain intact
Which specific brain area usually is associated with prosopagnosia?
the fusiform gyrus, which activates specifically in response to faces
The functionality of the fusiform gyrus allows most people to recognize faces in more detail than they do similarly complex inanimate objects
Which hemisphere is more often involved in face recognition?
The right hemisphere fusiform gyrus is more often involved in familiar face recognition than the left
Which two types of prosopagnosia are there?
acquired
and
congenital (developmental)
From what does acquired prosopagnosia usually results from?
Who experience it?
Acquired prosopagnosia results from occipito-temporal lobe damage and is most often found in adults
What two subdivisions of prosopagnosia do exist?
apperceptive and associative prosopagnosia
How is congenital prosopagnosia expressed?
In congenital prosopagnosia, the individual never adequately develops the ability to recognize faces
- Lifelong
- Manifesting in early childhood
- Genetic factor (several studies)
Nearby brain areas and associated disorders:
o Hemianopsia
o Achromatopsia
o Topographical disorientation
Hemianopsia
right occipital lobe; loss of vision from left side of space
Achromatopsia
temporo-occipital junction; color perception
Topographical disorientation
posterior part of parahippocampal gyrus and anterior part of lingual gyrus of right hemisphere; loss of environmental familiarity and difficulties in using landmarks
Apperceptive type
- Right occipital temporal regions
- Cannot make any sense of faces
- Unable to make same-different judgments
- Unable to recognize familiar and unfamiliar faces
- Struggle recognizing facial emotion
- Can recognize via non-face clues such as clothing, hairstyle, skin color, voice
Associative type
- Spared/intact perceptual processes
- Impaired links between early face perception and semantic information from memories
- Right anterior temporal regions
- Able to make same-different judgments
- Can derive age and sex from a face (some face information)
- But not able to then identify person with name, occupation, or last encounter
Caused by lesions in verious parts of..
inferior occipital areas, fusiform gyrus, anterior temporal cortex
Anterior temporal structures integrate info about ..
face, voice and name of familiar person
Vascular causes
Posterior cerebral artery infarcts, hemorrhages
Unilateral left lesions result in ..
object agnosia; if it affects face perception, mostly difficulties in person-specific semantic information
Can be diagnosed through..
Face tests
Benton Facial Recognition Test
Cambridge Face Memory Test
The 20-item Prosopagnosia Index
Faces tests:
o Have to recognize faces of famous persons
o difficult to standardize
Benton Facial Recognition Test
o Six test faces, one target face
o Have to tell which test face matches target face
o Images eliminate hair and clothes
o First six items: only one test face matches target; next seven items, three test faces match target
o :( Reliability questioned
o :) useful to identify apperceptive type, since it is mainly matching test, and they are unable to recognize familiar and unfamiliar faces
o :( not useful to diagnose associative type since they are able to match faces anyway
Cambridge Face Memory Test
o Three images each of six different target faces
o Then presented with many three-image series, with one image of a target face and two distracters
o More accurate and efficient than previous tests
o But similar to the BFRT, match faces and needs further testing
The 20-item Prosopagnosia Index
o Freely available and validated self-report questionnaire
o Validated
Treatment
No widely accepted treatments
Prognosis
- Impairments after stroke: low rate of success
- Sometimes it resolves spontaneously
Children
- Often unaware of their disorder and that others can distinguish people
- Disorder is often overlooked
- Children have hard time making friends
- Difficulties following TV plots; cartoons are easier
