1. Benton
Miranda Srnka

2.  Basic strategies underlying facial perception?
 How are faces encoded?
 Does spatial recognition have a special
status?... Determine this by asking is
impairment of this capacity an autonomous
deficit or one expression of a pervasive
visuoperceptive disability

3.  Failure to recognize or identify a visual stimulus w/
in the context of apparently adequate visuosensory
capacity
 FACIAL AGNOSIA (prosopagnosia)- incapacity of
patient to identify familiar faces on the basis of
visual perception
 Caused by bilateral disease (lesion to inferior
occipital area of right hemisphere)
 Simplest interpretation = impairment to analysis
and synthesis of complex visual stimulus
configurations that most clearly manifests itself in
facial recognition because its such a formidable
discriminative task (visuoperceptive disability)

4.  Some prosopagnosia patients can identify
unfamiliar faces quite well
 Patients with serve visuoanalytic and
visuosynthetic capacity generally do not show
facial agnosia
 There is something special about facial
recognition and its disturbances

5.  Incapacity to perceive individuality within a
single class of objects
 Material specific defect in memory (defect in
integrating current facial percepts with past
experience of them)
 *no single explanation is supported with
impressive empirical evidence b/c facial
agnosia is too rare to accumulate ample data

6.  Series of different facial recognition tasks
given to brain-disease patients to determine
relationship of performance level w/ locus of
lesion.
 A.) matching of identical front-view
photographs of a face
 B.) Matching of a front-view w/ views from
different angles
 C.) Matching of front-view photographs
under different lighting conditions

7.  Right anterior
 Right posterior
 Left anterior (nonaphasic)
 Left posterior (nonaphasic)
 Left anterior (aphasic w/o comprehension defect)
 Left posterior (aphasic w/o comprehension
defect)
 Left anterior (aphasic w/ comprehension defect)
 Left posterior (aphasic w/ comprehension defect)

8.  Patients w/ posterior right hemisphere lesions &
visual field defects performed at a lower level
than the rest of the groups
 Among patients w/ posterior right hemi. Lesions,
those w/ visual field defects showed higher
frequency of failing facial recognition
performance
 Only a minimal difference for patients w/ left
hemi. Posterior lesions
 Injury to central visual pathways in not a
determinant in failing performance on facial
recognition in patients with posterior lesions
 Right hemisphere plays a particularly important
role in mediating the discrimination of unfamiliar
faces.

9.  Group of patients with left hemisphere disease
that show noticeably high frequency of failure
in facial recognition (aphasic patients w/
defective aural lang. comprehension)
 Therefore, in addition to visuoperceptive
mechanisms of the right hemisphere,
mechanisms of the left hemi. are also involved
in the discrimination of faces
 Left hemisphere = linguistic (verbal encoding
of perceptions help out in facial recognition)
ex: “long nose” “she’s pretty” “big ears”

10.  Assumption that detection of familiar and
unfamiliar faces relies on the same capacities
proved incorrect
 Disabilities in identifying familiar and unfamiliar
faces are dissociative
 Prosopagnosia patients can identify unfamiliar
faces but not familiar faces.
 Prosopagnosia = bilateral disease (product of
occipito-temporal disease)
 Incapacity to ID unfamiliar faces = unilateral
hemispheric disease Impairment of facial
recognition comes in 2 forms… Prosopagnosia
and defect in discriminating unfamiliar faces.