Week 4

Question 1

Are the same mechanisms used for face

and object perception?

Answer 1

separate

Are the same mechanisms used for face
and object perception?
Support for specialist face processing module
Evolutionary argument

look at faces

facial expression

salient affective information
Empirical evidence for specialised face
processing module

Question 2

Neural mechanisms

Answer 2

Often co-occurrence of object and face recognition
impairments

impairments face recognition – associated with
multiple lesions

Bilateral lesions – multiple strokes, head trauma,
encephalitis, poisoning

Question 3

Single cell recordings - primates

Answer 3

Superior temporal sulc
us cells in monkeys
Stimuli presented were monkey faces, human
faces or stimuli that had characteristics
associated with faces
Found cells that selectively responded to

frontal monkey profile

others all facial stimuli
But cannot conclude cells purely for face
processing

Question 4

Dissociation of object and face recognition

Answer 4

Patients ok object recognition but poor at face
recognition
Explained by different levels of sensitivity of tests
used for object and face recognition

object – between classes
face – within same class

Dissociate Prosopagnosia from other forms of
agnosia
?

Question 5

McNeil & Warrington (1993)

Answer 5

Sheep farmer suffered multiple strokes
Pick famous faces from an array

Chance performance picking famous faces from unfamiliar
faces

Could pick sheep from his own flock compared to
unfamiliar sheep
Test recognition memory for faces and sheep

Human faces performance at chance

Sheep faces good for both hi
s own and unfamiliar sheep

Question 6

Farah et al (1994)

Patient LH

Answer 6

Patient L.H. – diffuse brain damage after accident
Two recognition memory tests

face stimuli

eye glasses
Study phase half stimuli presented
Test phase all stimuli presented
Task – judge stimulus old/new
Correct performance
LH          –  64%          faces
63%          glasses
Controls  - 85% faces
69% glasses
Agnosia – 98% faces
chance glasses

Question 7

Face Inversion Effect

Answer 7

Face recognition more difficult for inverted compared
to upright faces
Evidence – upright = holistic analysis
inverted = analysis by parts (cannot use face
system)
Predict impaired face recognition only upright faces

Normals – correct 94% upright, 82% inverted

LH – correct 58% upright, 72% inverted

Question 8

Unique face recognition processing?

Answer 8

Farah (1990)
Acquired alexia
Reading problems, read letter by letter
Visual confusions between words eg. ball doll
Left hemisphere lesion – angular gyrus posterior
region parietal lobe
(Temporal lobe – face processing)
Specific type visual agnosia – patients can
comprehend, speak and write

Deficit – within category (words)
Often occurs with impairments in object recognition
Object recognition – decompose stimuli into parts
Face recognition – overall configuration (holistic

Question 9

Viewer centred description to the expression independent description (similar to object centred description) (bruce&young 86)

Answer 9

Structural encoding of face ( formation of face
percept)

PARALLEL extraction of number types of face
information

Question 10

(facial) Expression Analysis

Answer 10

what expression is a person making

eg. happy, sad

Question 11

facial speach analysis

Answer 11

speaking, movement of mouth and tongue - lip reading

Question 12

Directed Visual Processing

Answer 12

manipulate facial representations

similarities/ differences between unfamiliar people

Question 13

Face Recognition Units

Answer 13

recognise familiar faces

Question 14

Face Recognition Units : Link

Answer 14

structural encoding face appearance to

person identity nodes

Question 15

Person Identity Nodes

Answer 15

stored information – known people

occupation, personal characteristics

Question 16

Face Recognition Units

Answer 16

structural description
known person’s appearance

fire – seen face resembles stored description

Question 17

Recognise familiar people via other

characteristics/ cues

Answer 17

such as voice, laugh

uses other routes to
access person identity nodes

Question 18

Prosopagnosia

Answer 18

inability to recognise familiar
faces

Bodamer (1947)

coined term Prosopagnosia

first report distinct face recognition impairment ?

Not unitary disorder
General term – inability to recognise familiar faces
Various causes
Identification of Different Types of Prosopagnosia
Difficult – deficit rarely occurs in isolation
Types - two distinct groups
Impaired ability to perceive faces

Defect affects Structural Encoding – model
Impaired face recognition

Intact perceptual abilities but
cannot recognise or process
faces satisfactorily

Question 19

Case study:

Prosopagnosia

Answer 19

Charcot (1883) and Wilbrand (1882)

Reported patients with face recognition problems
but patients also had widespread perceptual
problems and memory difficulties
Prosopagnosia patients
Unable to identify familiar faces

wives, family, friends, themselves in mirror
Know looking at face but cannot identify it
Can use other cues to recognise people

gait, clothing, voice, contex

Question 20

Covert face recognition - physiological

Patient LF

Answer 20

Patient LF (Bauer, 1984)
Task to select the correct name from five alternatives
to match a photograph of a familiar face
LF performed at chance
Skin conductance responses (SCRs) were greater
and more frequent to the correct name compared to
distractors
Tranel & Damasio (1985) – patient shown slides of
faces produced
↑SCRs to familiar faces compared
to unfamiliar faces

Question 21

Covert face recognition - behavioural

patient PH

Answer 21

De Haan Patient PH
Performs at chance on a forced choice terms
requiring to choose the familiar face from two items
Face matching task – are 2 simultaneously
presented faces are the same person
Normals are faster to indicate a match for familiar
compared to unfamiliar faces
P. H. also shows that effect

Question 22

covert face recognition - behavioural

Answer 22

Interference experiment – faces are shown with a
printed name
Name is that of the person, a person with a related
occupation, or an entirely unrelated person
Participants indicate if the name is that of a Politician
Normals take longer if t
he name is unrelated to the
face
P. H. also shows this effect

Associative priming experiments
A prime face is presented before a written name
target
Task decide if target is familiar or not
Normals – faster responses when the prime is
associated with a target compared to when there is
no association between the prime and target or the
prime is the face of an unfamiliar person
P. H. shows the same effect
Not all Prosopagnosia patients show convert effects,
some show affects only to a subset of known people

Question 23

Example of Patient with Defective Face
Perception
Unteroffizer S

Answer 23

Bodamer (1947) Unteroffizier S
24yr old non-commissioned officer wounded in 
1944
Result of injury could not recognise once familiar 
faces
Could still imagine what faces looked like
Faces all the same 

flat, white oval plates 
with emphatically dark eyes
Could differentiate between faces and most 
types of objects
Few errors on animal faces

rabbit – ok

dogs – no
Correct pick out features

nose, mouth, eyes but no s
ense of face individuality
Familiar faces did not  provoke feeling familiarity

failed to recognise his mother

Hairstyle able to dete
rmine age, gender of person

Defective interpretation of facial expression

report movements associated
with facial expression but
affective expression had no meaning

in front of mirror with ot
hers – see his own facial
movements but could not recognise himself
Bodamer concluded Uffz S – perceptual disorder
Ok individual face elements
Poor overall unique character
Therefore impaired feature and configuration analysis

Question 24

Example of Patient with Defective Face

Perception - pallis (55)

Answer 24

Pallis (1955) – patient see nose, eyes, mouth but
reported that they did not add up
Therefore deficit in seeing configuration formed by
individual features more severe than Uffz S

Question 25

Metamorphopsia

Answer 25

perceptual distortion

Question 26

Metamorphopsia (more info)

Answer 26

``` Bodamer (1947) Two patients saw distorted faces One patient described faces as having  noses turned sideways by several degrees  one eyebrow higher than the other  mouth askew  hair shifted like an ill-fitting cap Third patient metamorphic but could recognise faces to some extent ``` So either perceptual distortions not severe enough to prevent recognition OR perceptual impairments of Prosopagnosia not same as metamorphopsia

Question 27

Impaired Face Memory

Answer 27

``` Intact face perception Material specific memory impairment Mr W Bruyer et al (1983) - 54 yr old Belgian farmer unable to identify familiar people for 4 years impairment began whilst in hospital treatment cardiac problems CT scan  bilateral lobe lesions Verbal IQ 90, Performance IQ 95 (normal) Faces “less beautiful” Could see faces and face parts but could not recognise faces Was able to  distinguish between human faces  copy line drawings of faces  do gender classification  perceive and interpret facial expression  same/different expression matching  match expression to target  judge appropriateness facial expression with emotional state pictures eg. clown, funeral  match unfamiliar faces ``` ``` 18  discriminate between line drawings where at least one feature altered  pick target face from array  as with normal performance worse when stimuli blurred  if face perception problem then blurring no significant effect ``` match ¾ views to full face view of target  match target face neutral expression to those of same person with variety of facial expressions (hair occluded) Mr W adequate facial percept but unable to use differences between facial percepts to recognise Familiar Faces tests with hair-styles occluded (hoods) 10 famous faces, 5 cued named in prior discussion X Mr W 1 correct  normals 9.7 correct Video tapes X Himself, doctor, neuropsychologist, patient friend, 2 unfamiliar people X Doubtful about familiarity of himself but all other unfamiliar Impaired Face Memory Familiar Faces Without hoods – hair style seen  Recognise himself – long delay  Friends face – familiar  Might know – Neuropsychologist Task where faces familiar 8/20 correct X Of those rejected 8 he knew personally X Did not recognise celebrities as familiar Impaired Face Memory 20 Mr W Severely impaired tasks precise identification (naming) Some sense familiarity faces well known to him Problem accessing previously stored face memories Ok remembering people by spoken name or voice problem getting from actual face to memory representation Defective face recognition units faces

Question 28

Anomia (person name)

Answer 28

lack of knowledge of peoples names

Question 29

anomia peoples names case study

Answer 29

GBL McKenna & Warrington (1980) Patient anomic only for people’s names Could only name 3/20 photos of famous people correctly But could accurately describe 18/20 correct who they were Correct 16/20 European towns and 12/12 English towns

Question 30

Genetic basis prosopagnosia

Answer 30

Normal infants can recognize face like patterns a few hours after birth Newborn babies can distinguish between their mother’s face and the faces of other women at 2 days old Babies a few months old can recognize familiar faces The rapid development of face recognition suggests that this skill might be modular (Fodor, 1983)

Question 31

Developmental Prosopagnosia

Answer 31

Developmental Prosopagnosia Congenital Prosopagnosia One idea - developmental Prosopagnosia is caused by a generalized deficit in configural processing Evidence suggests that developmental Prosopagnosia runs in families

Question 32

Face Anosognosia

Answer 32

inability to recognise familiar faces along with the unawareness of this deficit and complete lack of acceptance Young, De Hann & Newcombe (1990) Woman suffered a severe right hemisphere stroke  poor at recognizing familiar faces She was completely unaware of this impairment Complete lack of acceptance of this impairment Able to recognise other cognitive limitations Possibly explained by the automaticity of face recognition