Lecture 2: Recognising faces Flashcards
(27 cards)
how many faces do people know ?
5000
what is the inversion effect? (Yin 1969)
identifying inverted (upside-down) faces is significantly more difficult than identifying upright faces7. This effect is much more pronounced for faces compared to other objects17. Key points about the face inversion effect include:
It demonstrates a disproportionate impairment in recognizing inverted faces compared to inverted non-facial objects7.
The effect is thought to occur because inverting a face disrupts the holistic or configural processing typically used for facial recognition37.
When faces are inverted, the brain switches from holistic processing to a more feature-based approach, similar to how it processes object
what is the ‘thatcher effect’?
phenomenon in face perception where it becomes difficult to detect local feature changes in an inverted face, even though these changes are obvious when the face is upright.
Configural coding of face is sensitive to spatial relations and orientation of features may be compromised
what is the composite effect? (Young et al)
It occurs when the top half of one face is aligned with the bottom half of another face, creating a compelling illusion of a new facial configuration17.
Recognition of the top half of a face is significantly impaired when it’s aligned with a different bottom half, compared to when the halves are misaligned34.
The effect is typically stronger for upright faces than for inverted faces, though recent research suggests a reliable inverted composite effect with larger sample sizes4.
It’s considered evidence for holistic face processing, as it shows that we tend to integrate information from different facial regions into a unified representation
what is the part-whole effect ‘Tanaka and Farah’
Participants are better at recognizing facial features when presented within the context of a whole face compared to when shown in isolation15.
This effect is specific to upright faces and is not observed for inverted faces, scrambled faces, or non-face objects like houses1.
The effect is more pronounced for certain facial features, with eyes and mouth showing a larger benefit from whole-face context than the nose1.
It supports the idea that faces are encoded and remembered as integrated wholes rather than as collections of individual parts4
What did tanaka and sengcro in 1996 go onto say?
- Similar effects of spatial relations
- Worse performance when spatial relations change
what did diamond and carey do in 1986
Second order spatial relations
* First order relations are constant in all faces
* Sometimes authors refer to this as ”configuration
what do tanaka and farah empahsise?
- Holistic representations
- Represent the whole face including all its parts and their spatial relations
how are both studies important?
- Both things are important and they are difficult to separate
- Configural and holistic used interchangeably to mean
- Whole face including the parts and their relations
what is Prosopagnosia?
inability to recognise faces
following brain damage
e.g Patient F.B Riddoach et al 2008
what was moscovitch et al’s study in 1997?
CK - spared face sees faces, but didn’t realise the faces were made of objects.
what does fmri do when studying facial perception?
- Blood oxygen level dependent response
- Shows which bits of brain are more acctive in response to brain stwhat does imuli
- Explosion of work in 1990’s
what did kanwasher et al 1997 find?
- Landmark study
- Identified an area of the ventral temporal lobe
- In the fusiform gyrus
- Primarily in the right hemisphere
- Showed a selective response to faces
- Argues for a “module” specialized for faces
explain bruce and young’s fictional model #
structural enoding = stage 1
- compute visual description to enable recognition of expression.
expression independent descriptions = stage 2
-Capture individuals encoding those aspects that are critical to differentiate people, stable across views.
expression pathway = stage 3
- Visually specified semantic information e.g Expression but also age gender etc.
Identify pathway
Identify specific semantic information.
Separate pathways for expression and identity.
what are the behavioural approaches ?
- Etcoff (1984) Card sorting
- Calder et al (2000)
- Composite effects for identity and emotion independent
what are the two major pathways accordig to haxby et al’s influential model?
One from visual cortex via FFA identity
One from visual cortex via superior temporal lobe
stages of facial identification/
Face recognition
- FRU; stored representation of particular face
- Structural code matches FRU gateway to fruther info about face
- According to bruce and young activation have signals familiarity to observer.
Person identification:
- ‘this person is into football and takes ps425’
- PIN - code semantic info about people
- Occupations, relationships, preferences
Name generation ‘it is john’
- Putting a name to a face.
what are the dissociations between stages?
1) Possible for someone to be familiar without knowing anything about them
* 2) Possible to know things about a person without knowing their name
* 3) Should be difficult or impossible to have access to a name without other
information
* Diary studies (e.g. Young et al., 1985) show that 1 and 2 are common but 3 is rare
what is priming?
studies examine the effect of previous exposures of certain stimuli on performance
what studies investigated this?
(Bruce & Valentine, 1985) - repetition priming
Semantic priming of face identification Young et al. (1994)
explain semantic priming
When processing faces we access semantic information
* Accessing semantic information speeds access
* Semantic information for faces
* Shared by multiple faces
* Organised around relationships
what was Gauthier & Tarr (1997) expertise hypothesis?
Faces are not special because they are faces
* Faces are special because we have the most expertise with them
* We are expert at individuating specific faces
touch on greeble experiment
what is capgras delusion?
- Patients claim that people they know
- Close relatives, like mother, father spouse
- Have been replaced by duplicates
- They look like that person but they are not that person
- Sometimes robots or clones
e.g. Patient DS Hirstein and Ramachandran (1997)
