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