Facial Recognition
- Created by: Jessica Harrington
- Created on: 29-03-13 13:02
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- Facial Recognition
- Bruce & Young Model
- States face recognition involves a small set of distinct processes; recognising individuals; emotional states (which are present for social & evolutional purposes) & understanding speech.
- These processes occur in seperate stages 1 after the other. The diagram shows the order of processes & how each stage is linked.
- Recognising faces helps a person detect danger or be able to interact meaningfully with someone they've met before.
- These processes occur in seperate stages 1 after the other. The diagram shows the order of processes & how each stage is linked.
- Bruce & Young thught for a face to be familiar it has to be seen on several occassions & in different contexts.
- The more memory traces stored from different occassions & contexts the more familiar the face becomes.
- They also thought that facial perception is a holistic process based on the features as a whole rather than seperately.
- The process begins with seeing a gface, which leads onto structural encoding where you decide on things like if its a face, the persons gender etc.
- Speech & expression is analysed to check whether you know the person or not, it also tells you what mood the person is in eg whether they are a threat.
- The next stage is FRU's where you decide if you know the face based on stored structural descriptions of known faces.
- The theory is for facial recognition only, implying that face recognition is seperate from recogntion of objects.
- States face recognition involves a small set of distinct processes; recognising individuals; emotional states (which are present for social & evolutional purposes) & understanding speech.
- Case Studies
- Young et al: studied 3 prosopagnostic patients who had all suffered brain damage.They couldnt tell that a face was or wasnt a face & analyse it any more than that.
- They couldnt do the first stage of structural encoding sp supports the placement pf encoding in the model & that further processing relies on it.
- De Hann et al: cites a case study of a patient who suffered brain damage. Could classify faces or non faces correctly but could go no further in the processing of the face.
- This shows that structural encoding is possible without the use of cognitive systems & that further analysis is a seperate stage.
- Flude et al: explained a case study where a patient could percieve faces correctly & whether they were familiar or not, he could also recall semantic info about the faces but he could not name the person.
- This supports the model idea that name generation is the last process & not needed for further recognition.
- Yin: used inverted recognition test of objects & faces. Inverted objects suffered 10% deficit compared to up right objects but faces suffered 30%.
- Supports idea that facial recognition is a seperate process.
- Sergent: found p.s could decide if 2 identikit faces were different more quickly when 2 dimensions were different rather than 1.
- Suggesting they were looking at the faces as a whole rather than individual features. Supports the concept of holistic processing.
- Young et al: studied 3 prosopagnostic patients who had all suffered brain damage.They couldnt tell that a face was or wasnt a face & analyse it any more than that.
- Explanations of Prosopognosia
- Agnosia is Greek for 'not knowing' & refers to a disorder relating to whatever comes before it. Visual agnosia refers to visually not knowing or not being able to recognise things.
- Prosopon is Greek for face/mask. :. prosopognosia is the inability to recognise familiar faces.
- Visual agnosia is usually divided into 2 parts.
- Apperceptive: an inability to recognise objects (including faces)
- Associative: to do with associated knowledge.
- Typically people can recognise or match names to faces/objects but cannot say anything about them.
- Studies of prosopognosia patients support model.
- Agnosia is Greek for 'not knowing' & refers to a disorder relating to whatever comes before it. Visual agnosia refers to visually not knowing or not being able to recognise things.
- Evaluation
- Main problem with evidence is that majority is case studies.
- Cant generalise to the rest of the population with case studies as it is a specific case
- As there are so many case studies to support model it is safe to assume the evidence is valid and generalise it.
- Cant generalise to the rest of the population with case studies as it is a specific case
- How Science Works.
- All case studies tested through overt behavioural measures which may be unreliable.
- Methodological issue: what is meant by a familiar face? The case studies may have used different meanings & it is impossible to classify what definition should be tested.
- It is unclear whether PIN's store or just access info.
- P.A include the use of security systems that use facial recogntion.
- Main problem with evidence is that majority is case studies.
- Bruce & Young Model
- Ethical issues: sensitivity issue.
- emotional for p.s not being able to recognise faces and loved ones, may cause stress/upset.
- Would have to gain consent & measures would have to be taken to support p.s in order for ethical treatment.
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