Lecture 3 Face Perception Flashcards
Evolutionary reasons we develop ability to recognise faces
Have specific brain area thought to process primarily faces (FFA)
Innate template of the human face means we are predisposed to recognise and interpret
Environmental reasons we develop an ability to recognise faces
Exposure to faces from birth, specifically human, allows us to distinguish
Describe fantz 1963 infant face preference
Presented infants with 3 faces where features arranged either naturally, scrambled or a control - matched for contrast
measure fixation time on stimuli as an indicator of preference
4d/o prefer structured natural face over both scrambled and control
+ compare with complex patterns of bullseye, b+w text, face and pattern with similar facial structure
- look long at patterns but longer for face
Problem with face preference study in infants (fantz 1963)
May just be recognising patterns not faces
A too complex to and b too simple
Describe Maura and Barrera 1981 face preference in infants
Matched stimuli for symmetry and contour - tested after habituation
Faces arranged naturally symmetrical, scrambled symmetrical or assymetric scrambled
Results of Maura and Barrera 1981
1 month - infants show now discrimination between stimuli
2 month - discriminate all and show preference for natural symmetric > others
role of experience?
Describe Johnson and Morton 1991 face preference via infant tracking
Slowly move stimulus across infants line of sight
1 month Track face like stimuli further than scrambled or blank
3-5 month no longer discriminate - track to same extent across stimuli
What do face preference studies show
Preference to static naturally arranged faces by 2months
Preference to moving naturally arranged faces from birth
Describe Johnson and Morton two process theory ‘CONSPEC AND CONLERN’
paradox in infancy CONSPEC Mediates tracking 0-1 month Innate template for directing attention to faces
CONLERN
Mediated static face recognition via learning
1+ months
CONSPEC theorised to ‘‘train up” CONLERN by regulatin approach behaviour/attention to facial sitmuli
Describe CONSPEC
Infant has innate info on structure of faces (not specific to humans) in subcortical visuomotor system
Mental architecture - contain relative structural architecture about location of elements
Not species/genus specific - only need to identify from other stimuli
Describe CONLERN
CONSPEC trains up CONLERN
Direction to conspecifics of face allows learning of visual characteristics
Build representations for stimuli that we encounter (superior processing of this)
perception in cortex
Describe Pascalis et al - face processing over time
6-10m infants ability to discriminate between native speech sounds increases while decreases for foreign sounds
Looking paradigm - 6+9months familiarised to human and monkey faces
Time spent looking at novel human or monkey faces compared to familiar
Results of Pascalis et al
Adults not good at recognising differences between old and new monkey faces but good with humans
6m can discriminate equally well between monkey and human faces - recognise new stimuli regardless of previous exposure
9m discriminate as adults
Describe sangrioli and deschonen 2004 race discrimination and expertise study
tested face recognition in 3-month-old Caucasian infants by conducting two experiments using Caucasian and Asiatic faces and a visual pair-comparison task
Define the other race effect
Inability to distinguish between other races due to limited exposure
Results of sangrioli and deschonen
her race effect develops together with face processing skills during the first months of life
recognition performance was better for Caucasian than for Asiatic faces
Describe diamond and Carey recognition with expertise stimuli
looked at expertise of dogs and birds using inversion paradigm on people expert in field
experts show same skill in identification as those in human face detection
Describe Gauthier et al 2000 FFA in face and stimuli processing
prev research suggests FFA specific to facial processing theorefore objects should show dissociated activity
Describe Kanwisher 2010 effect size in fmri FFA studies
against expertise
Large effect size shouldn’t be ignored as determines strength of inference in mri
Studies using other stimuli other than faces have sign effect but smaller effect size
higher res imaging techiniques fail to show more than half the response in FFA for objects compared to faces
Define social cognition
Encoding storage retrieval and processing of info relating to conspecifics
Anything for later to interactions with the world around us
why is face perception in infancy important for development
facilitate social interaction and commnication
allows us to respond appropriately in social situations
cassian, suman and umilta 2001 evolution and face perception
preference for neural facial stimuli when in periphery > direct, reflected onto area that is governed by primiteive brain centres
johnson and morton 1991 face tracking in older infancts
by 5 months tracking disappears and begin to track all stimuli to the same extent
prefer static > other stimuli at 2+ m
prefer track > other stimuli under 3m
no preference following 5m
age development of conspec and conlern face processing
0-2 months
conlern acquires knowledge of human faces
end of 1st month, conlern reduces influence
2-3m
cortical structures begin to control infant response
inhibit subcortical pathways underlying conspec
5m
conlern has good knoweldge of faces
decreased pref for static over other stimuli
feinham and entwisle 1976 other race effect
larger other race effect in children and adolsecnet in US segregated communities than those that are more integrated
sangrioli et al 2005 other race effect
eval of face recog abilities in adults of korean origin adopted by european caucassian families between 3-9years compared to native european and native korean
match to target paradigm: show target then must identify target from set of two pics
korean adopted show similar race discrimination to european while native korean better at own
- discrimination dependent on experience and early experience with one group can be reversed through later experience
why might perceptual narrowing of race identification be beneficial (mckone and robbins 2010)
means can better identify individuals from own group
the eyes in face detection
batki et al 2000
farroni et al 2002
batki - prefer open>closed eyes
prefer direct>averted gaze
the expertise hypothesis
diamond and carey 1986
face specific processing forms mechanism that can apply to all objects/stimuli - tends to be restricted to faces due to practice facial identification via experience and less experience with other species
BUT development not limited just to early experience
can be expertised in other domains - mechanism becomes specialised to whatever is necesary
results Gauthier et al 2000 FFA in face and stimuli processing
bird experts > birds and faces > obects and cars
car experts > cars and faces > birds and objects
bird experts: birds and faces cause increased activity in right and left FFA and right OFA (occ face area)
car experts: cars and faces cause increased activitiy in central right FFA and right OFA
activity greater overall for faces (innate?) BUT experience means can adapt to other stimuli
mckone and robbins 2010 cortex and object/face processing
extrastriate appears to be for more object general processing
lateral occ cortex prefer objects > scrampled objects and have close to equal activation for both objects and faces
genetics in face processing - prosopagnosia
prosopagnoia is a genetic disorder that impairs facial recognition and is highly heritable
suggests specific problem in genetic influence/development
BUT deficit of gene for prospagnosia may simply be about the attentional awareness of faces or for a social interest - uncertain as of yet
