MT1 intro to social/developmental psych- faces Flashcards
How is perception of faces different to perception of objects
Faces are complex and dynamic, fine discrimination needed within and between people to identify different people or at different angles, faces have social importance
What is the fusiform face area
The fusiform gyrus- area of the brain that is activated more to face than non-face stimuli
How is there double dissociation for face and object processing in adults
Acquired prosopagnosia- specific to recognition of human faces
Suggests object and face processing function independently of one another
What are domain general processes
Processes that might serve learning, perception etc more generally, that become specific over time with experience with faces, but aren’t necessarily face-specific to begin with
Johnson et al (1991) experiment 1- procedure
30min old neonates, tracking procedure following head and eye turns to face-like stimuli- one face-like representation, one scrambled face (same complexity and no of perceptual features), one blank
Johnson et al (1991) experiment 1- results
Babies tracked longer with eye and head mvoement for face stimuli, then scrambled stimuli, then blank stimuli
Johnson et al (1991) experiment 2- procedure
Same eye and head tracking of neonates
Face stimuli, configurational version of a face (v stripped down), upside-down configurational version, scrambled linear face
Johnson et al (1991) experiment 2- results
No effect of condition for head turns
For eye tracking- face stimuli, then a tiny bit below is config stimuli, then inverse and scrambled linear face
Suggests neonates prefer facelike stimuli even with equally visually salient stimuli
Study showing faces are special to infants even before they are born
Reid et al (2017) Face-like or inverted stimuli of lights projected across maternal abdomen moving across the fetal visual field
Ultrasound scans found more foetal head-turns to face-like configuration
Johnson et al (1991) experiment 2- criticism
Reporting of data is sparse
Study showing face preference varying over first few months
Johnson et al (1991)- decline in face preference between 1 and 2 months, that reemerges around 2-3 months
What do U shaped developmental curves often suggest
The operation of 2 systems- the first cruder and easier to deploy, then during the transition to the 2nd more complex system there is a drop in performance before an even higher level is achieved
Two-process theory of face processing- what are the 2 pathways
Johnson and Morton (1991)-
1) CONSPEC (specific) 2) CONLEARN
Two-process theory of face processing- what is CONSPEC
Johnson and Morton (1991)-
subcortical visuomotor pathway responsible for preferential tracking of faces in newborns (akin to FAP)
Two-process theory of face processing- what is CONLEARN
Johnson and Morton (1991)- adult-like cortical pathways specialised for faces that emerge over time as a consequence of experience
Two-process theory of face processing-how do CONSPEC and CONLEARN work together to develop
Johnson and Morton (1991)- CONSPEC predisposes infants to be interested in faces and attend to them, providing substrate that fuels the development of CONLEARN, which may in turn inhibit CONSPEC
Two-process theory of face processing- summarise how CONSPEC leads to the emergence of a face area in the brain
A region of brain receives input only from ovals with inverted triangles
This inverted triangle bias causes the brain region to receive only face-like input, causing it to gradually become specialised for faces
Criticising CONSPEC- doesn’t explain preference for attractive faces?
Slater et al (2000)- faces judged by adults as more attractive (more average, more symmetrical) are looked at for longer by neonates
Only for upright faces, internal features seem important
Too complex behaviour for simplistic CONSPEC
Criticising CONSPEC- doesn’t explain preference for direct gaze?
Farroni et al (2002)- babies preferentially look at faces with direct gaze compared to averted gaze
Processing too sophisticated for CONSPEC?
Criticising CONSPEC- is it really face specific?
Cassia et al (2004)- infants have a preference for top-heavy configurations that not specific to faces
Criticising CONSPEC- possible explanation preferences for attractive/direct gaze/top heavy faces?
Better fit to ‘face prototype’ that CONSPEC may be looking for?
Criticising CONSPEC- need for 2 process theory?
Data also consistent with gradual development of a single mechanism, reflecting an immature adult system
Criticism of study suggesting neonate preference for HUMAN faces
The human and non-human primate faces used differ in lots of ways- brightness, concentration, contrast… lower level perceptual features may drive looking preference
Study showing no human-specific neonate preference in first week of life
Di Giorgio et al (2012)- 1-3 day old infants shown a human and monkey face matched for perceptual factors eg LSF- they showed habituation so could discriminate the faces, yet showed no looking preference for either face, and preferred upright monkey faces just like with humans
Study showing no human-specific neonate preference in first week of life- what do the results suggest
Monkey faces are initially processed in the same way as human faces (same effect of inversion consistent with top-heavy prototype)
Criticism of stimuli used in most face-processing experiments
Stimuli are often 2D isolated faces, or face-like schematic stimuli- in the real world stimuli is very varied and complex eg lots of different angles, movement, which may drive learning (Jayaraman et al, 2017)
Study measuring detection of salient vs non-salient faces- procedure
Kelly et al (2019)- monitored eye movement of 3-12 mos viewing scenes with a person present vs absent, and salient vs non-salient
Face was considered ‘detected’ if the first detected movement post-stimulus onset was to face
Study measuring detection of salient vs non-salient faces- results
Kelly et al (2019)- more first looks to faces than equivalently salient non-face areas of interest
Salient faces more detected than non-salient faces
Study measuring detection of salient vs non-salient faces- conclusions
Kelly et al (2019)- babies attend to faces regardless of salience, despite varying spatial location, small visual angle and much competing info
MORE IMPRESSIVE FACE DETECTION THAN ASSUMED FROM ARTIFICIAL STIMULI
Study supporting experience-based learning of face preference in monkeys- procedure
Sugita (2008)- monkeys were separated from their mother at birth and not exposed to faces for 6, 12 or 24 months
Looking preferences to human and monkey faces, and objects was then tested
Study supporting experience-based learning of face preference in monkeys- results
Sugita (2002)- monkeys showed interest in faces despite no experience of faces but NOT SPECIES-SPECIFIC
1 month post-deprivation- human experience leads to human preference, monkey experience leads to monkey preference
Preferences maintained for at least 12 months after exposure become general
Study supporting experience-based learning of face preference in human infants vs adults- procedure
Pascalis et al (2002)- adults, 6mos and 9mos do a visual paired comparison paradigm
Familiarised to one human/monkey face then test for a novelty preference to new face (suggests discrimination)
Study supporting experience-based learning of face preference in human infants vs adults- results
Pascalis et al (2002)- adults and 9mos don’t show looking preference between new and familiar monkey faces- can’t distinguish them
6mos show novelty preference to monkeys as well as humans, better at discriminating monkey faces than older people
What does it suggest that 6mos can discrminate monkey faces but 9mos and adults can’t (Pascalis et al, 2002)
Infants improve at processing stimuli that are meaningful for the environment (human faces), and lose the ability to process stimuli that are irrelevant to the environment (monkeys)
Experience-based learning in face processing
Study supporting face processing development as perceptual tuning
Pascalis et al (2005)- infants exposed to monkey faces between 6 and 9 months maintained the ability to discriminate monkey at 9 months
Suggests we improve our judgement on things that are relevant and frequent in our life
What is the other-race effect (ORE)
Human adults are expert at recognising faces, but susceptible to errors when the target face is from an unfamiliar racial group
How can the ORE be partly explained by experience
We each develop a unique face prototype, the average of all faces we have seen
Optimal tuning is based on experience we will not be well equipped to distinguish faces from an unfamiliar racial group
Study supporting emergence of ORE in infants
Kelly et al (2005)- Caucasian neonates and 3mos do a visual preference task for different race faces
Neonates show no looking preference
3mos- slight looking preference to Caucasian faces, no difference when 2 Caucasian faces are paired
Study supporting emergence of ORE in infants- what conclusions can be drawn from Kelly et al (2005)’s study
Preferential looking for own-race faces emerges by 3 months
Broad and unspecified neonate face processing system becomes tuned to a facial prototype to own-race dimensions through early predominant exposure to own race
Causes preference to familiar own-race face stimuli
Study into discrimination of different races faces in infants
Kelly et al (2007)- tested 3, 6 and 9mo caucasian infants, shown a test pair containing a novel and habituated face
3mos- can discriminate between 2 faces across all races
6mos- can discriminate Chinese and Caucasian faces
9mos- can only discriminate Caucasian faces
When does Kelly et al (2007)’s study suggest ORE emerges
No ORE at 3 months, partial at 6 months, complete at 9 months
What is the consequence of developed preference towards own-race faces as the more familiar class of faces
We develop superior recognition/discrimination for faces of our own racial group
Study suggesting cultural effects in adult eye movements
Kelly et al (2010) Caucasian obervers show more looks to eyes and mouth, East Asian observers show more looks to nose
Looking pattern generalises to sheep faces, and even to non-face stimuli of greebles
What are Greeble stimuli
Invented category of novel objects with small no of parts in common configuration
Study showing Caucasian development of face scanning patterns
Wheeler et al (2011)- for own race, interest in eyes increases with age, mouths go down (nose no change)
Study showing Chinese development of face scanning patterns
Liu et al (2011)- for own race, interest in noses increases with age, for other race, nose interest declines with age
What do cultural differences in scanning patterns in infants reflect
Attention being directed to parts of the face that promote meaningful information for that environment (eyes for Caucasian, noses for Chinese)
How are cultural differences of scannign patterns generalised once adopted for faces
Extends to other race faces, animal faces, and non-face stimuli
What is autism
A pervasive neurodevelopmental disorder- characterised by qualitative impairments in social/communicative/imaginative behaviors, and repetitive stereotyped patterns of activity and interests
What is the social hypothesis for differences in face-processing in autistic people
Reduced interest in/motivation to process faces -> face processing differences
What is the non-social hypothesis for differences in face-processing in autistic people
Differences in general processing -> face differences
What conditions have been proposed for a study to argue for face-specific differences in neurotypicals vs people with autism
Ewers et al (2013) Studies must
1) Establish a statistic interaction between face/non-face conditions
2) Non-face condition of comparable difficulty and complexity
3) Large sample (heterogeneity)
Autism face-processing study- procedure
Ewers et al (2013)- autistic and neurotypical children shown faces, cars and inverted faces in discrimination and memory tasks
Autism face-processing study-findings
Ewers et al (2013)- for both memory and discrimination tasks, main effect of group aka autistic children behave differently across face/car/inverted condition
No interaction between condition (stimulus type) and main effect
Autism face-processing study- conclusions drawn from main effect of group
No evidence for SELECTIVE FACE processing deficit
Suggests general processing differences impact face processing in autistic people
Reduced social motivation (social hypothesis) unlikely to be sole explanation of differences in face processing in autism