Face Perception Terms Flashcards
Intraclass discrimination
between members of the same stimulus category
Eg. poodle vs border collie
Interclass discrimination
between members of different categories
Eg. dog vs cat
First-order arrangement information
spatial relations between constituent parts of an object; all faces share common first-order information
Eg. all eyes located above the nose
Second-order relational information
relative size of spatial relations between parts of an object; individuals differ on second -order information
Eg. John has closely set eyes, Maria has a small nose
Face Patch
specialized mechanisms for face perception; brain circuits that are not used in the perception of other objects
Eg. newborn infants: gaze longer at pictures of mother than of a stranger, look longer at attractive faces, can discriminate and imitate facial expressions at 36 hours after birth
Eg. double dissociation of W.J (prosopagnosia: could identify sheep faces but not human faces) and C.K. (visual object agnosia: can’t identify things visually but had intact face perception) shows support for existence of distinct face-processing regions
Isolated-part condition
given a choice of two object parts, pick why one had been presented before
Eg. which of these is Larry’s nose? Or Which of these is Bill’s door?
Whole-Object Condition
given a choice of two whole objects, pick out the one they had seen earlier
Eg. Which of these is Larry’s face? Or Which of these is Bill’s house?
Inversion Effect
upside-down faces are more difficult to identify; perception of features is unaffected, shows faces are represented as undifferentiated wholes, inversion interferes with this processing, necessitating feature-by-feature analysis
Eg. Thompson (1980) experiment, inversion of faces caused people to be slower and less accurate then when face was right side up
Fusiform Face Area (FFA)
located in right lateral fusiform gyrus (in inferior temporal lobe), fMRI found face specific attention activated FFA more strongly than objects of similar complexity
Relate: FFA damage = prosopagnosia
Fusiform gyrus
contains FFA, in inferior temporal lobe, PET scans found right fusiform gyrus activity is greatest during face memorization tasks, activity correlates with performance
Prosopagnosia
failure in the visual processing of faces which is not due to a general intellectual impairment, sensory impairment or language disorder, caused by damage to FFA
Eg. W.J case study: RH damage and had severe prosopagnosia, normal visual acuity and normal LH functioning, worse at recognizing human faces than individual sheep from a flock he had acquired after prosopagnosia developed. Recognition memory performance with unfamiliar sheep surpassed that of normal controls, matched for profession and experience with sheep. W.J. has a face-specific deficit not generalizable to other classes of complex stimuli.
Occipital Face Area (OFA)
located in inferior occipital gyrus; activated by individual facial features
Superior temporal sulcus (fSTS)
face selective region in STS, sensitive to face parts not to correct facial configuration
Greebles
imaginary faceless plantlike creatures, used in tasks where they have to be classified according to sex and family.
Different families and different individuals. When pairs of matching greebels are identified it elevates fusiform gyrus activity.
Does not activate the right anterior fusiform area.
Prosopagnosia individuals show deficits in intraclass discrimination of greebles, but visual object agnosia could not discriminate greebles
Apperceptive Prosopagnosia
impairment in basic face perception; patient cannot “see” faces normally, cannot determine they are looking at a face and hence cannot identify it. Visual association areas within right occipital and temporal regions
Eg. faces don’t look normal anymore, are distorted and look like sketches by Picasso
Case study of Unteroffizier S: patient unable to identify previously familiar face, including famous faces, friends, family an patient’s own face in a mirror
Associative Prosopagnosia
can determine they are looking at a face but associated information can no longer be retrieved, preventing identification, right anterior temporal regions implicated
Eg. Case study of Mr. W: 54-year old Belgian farmer could copy drawings of faces, match faces, determine gender through faces, poor at identifying famous faces and at familiarity judgment of personally known faces
Capgras Syndrome
delusion that a close relative or friend has been replaced by an exact double - an imposter, imposter is a key figure for the patient at the time of onsent of symptoms,
patient may also see themself as their own double, may believe that inanimate objects have been replaced by exact doubles,
not obtained when talking to people on the phone,
associated with brain injury, history of delusions, psychoses (may be interaction of brain injury and delusion), may be failure for recognition to elicit appropriate emotional output
Eg. those with Capgras do not have normal GSR to familiar faces
Can identify faces but lack emotional response to them
Problem may be underactivation of normal autonomic arousal
Fregoli Delusion
patient has delusional belief that different people (strangers) are one single familiar person who changes appearance or is in disguise.
Patient usually believes this familiar person to be a persecutor who is following them, named for famous actor
Leopoldo Fregoli who was renowned for his ability to make quick changes in appearance during stage act.
Right anterior fusiform gyrus damage is implicated as well as temporal lobe locations involved in face recognition
Problem may be excess inappropriate arousal to viewing unfamiliar faces in temporo-limbic connections
Distinctive Faces
coded further out on face-space dimensions, stand out from the crowd due to lower face density, so more memorable
Average Faces
cluster densely around center; more conusable with neighbours so less memorable but more familiar and attractive
Evolutionary advantage view
attractive face is adaptive for mate choice, may signal important aspects like health, high cross-cultural agreement on attractiveness, preferences emerge before cultural standards of beauty are learned
Eg. attracted to symmetrical faces because they represent health.
Evolutionary hypothesis: preferences for symmetrical faces should be weaker when they are inverted (less mate-relevant)
Perceptual Hypothesis: inversion does not affect symmetry so preferences should be unchanged
In experiment treated upright faces as mate choice relevant stimuli and inverted faces as objects. Saw decrease from 57% preference of upright symmetric faces vs asymmetric to 52% for inverted symmetric faces. Favours evolutionary over perceptual
Perceptual Bias View
preference for attractive face is a byproduct of visual information processing, like to look at things that are easier to process, beauty in averageness effect (people tend to prefer highly prototypical stimuli over unusual exemplars), average face is similar to mental face prototype thus is more easily processed
Eg. prefer symmetrical faces as it is easier to process symmetrical stimuli
