Visual Agnosias

Which three psychologists can use their studies to support Prosopagnosia being face specific?

Barton et al (2002) Hadjikhani (2003) Farah et al (1995)

How is confidentiality kept in Prosopagnosia research?

Referring to them with their initials e.g. HM

In extreme cases, what are people with Prosopagnosia unable to do?

Recognize themselves

Give one example of an associative agnosia

Prosopagnosia

Define Prosopagnosia

Inability to recognize faces despite intact intellectual functioning and visual recognition of other stimuli.

What is a visual agnosia?

Inability to recognize familiar objects presented visually

How are greebles similar to faces in terms of processing? (2 ways)

1) can both be processed through configuration 2) all only have small differences, like faces do

Give two reasons why the study of Prosopagnosia is important

1) Can help our understanding of normal face recognition processes 2) Help identify areas in the brain which are involved in recognition

Outline the two dominant explanations of Prosopagnosia

1) Face Specific Problem 2) Not a Face Specific Problem

Give one weakness of Gauthier's explanation

1) Prosopagnosiacs can identify greebles (OBJECTS), but still not faces - suggests faces and greebles do not use the same brain mechanism - is it not the FFA?

Suggest two weaknesses of using case studies in research for Prosopagnosia

1) Small sample so results cannot be generalized to EVERYONE suffering from Prosopagnosia, particularly as there has been conflicting evidence 2) Damage to the brain is different for everyone - some damage = bullet wounds, others from a stroke, so difficult to precisely locate the problems caused by any one part of the brain

Barton et al: How many of the participants in Barton's study did NOT have brain damage to FFA? What were the consequences of this?

1/5 did not have FFA damage, and performed normally when asked to discriminate between faces

Barton et al: How many of the 5 performed poorly when discriminating between the faces? Why?

4/5 because they had damage to their FFA

How many participants did Barton et al use? What did they have damage to?

5 Prosopagnosiacs with brain damage to their FFA (fusiform face area)

Barton et al: What had happened to the features on some of the faces?

Altered slightly - vertical position of mouth, distance between eyes

How can case studies into Prosopagnosia have a real life application?

Although nothing can be done to treat Prosopagnosia, understanding of the causes can help comfort and explain to sufferers what they are dealing with

Explain the difference between apperceptive agnosia, and associative agnosia

Apperceptive agosia = Impaired visual perception so failure to form a correct percept of stimulus Associative Agnosia = Intact perceptual ability, but inability to interpret, or assign meaning to to an object or face due to difficulty accessing relevant knowledge from memory

What did Gauthier et al (1999) computer generate in his study?

Artificial objects called greebles

How were the cows seen in the farmer study? Why?

As objects because they all look the same

Barton et al: What were the participants asked to do?

Asked to discriminate between faces in which the features had been altered (e.g. vertical position of the mouth)

What kind of equipment did Gauthier use?

Brain scan

Whose model of face recognition can also provide support for there being a specific facial recognition centre?

Bruce and Young's

How can Farah support Barton AND Hadjikhani?

Case study LH could discriminate between familiar objects such as chairs, but not between faces

In people with Associative Agnosia, what can difficulty accessing relevant knowledge from memory lead to?

Inability to interpret or assign meanings to an object or face

What ethical issues may have arisen from using case studies in Prosopagnosia research? Give one example.

Distress - because Prosopagnosia is such a confusing disorder, individuals are usually kept in studies for years - can be distressing. Man who suffered stroke in 1981 and still tested years later.

Which area of the brain is more active during facial recognition, but LESS active during object recognition?

FFA (fusiform face area)

What have a number of case studies shown to support Prosopagnosia being a specific face recognition problem?

FFA is activated during face recognition, and less during object recognition

Who else can provide support for Barton, as well as Hadjikhani?

Farah et al (1995)

How can the study of a farmer support Gauthier?

Farmer suffered brain damage, and could no longer identify is cows (objects) - supports Proso not just being face specific

How does Hadjikhani support Barton et al?

Found those with Prosopagnosia showed no FFA activation when viewing faces, compared to those without disorder whose FFA did activate when viewing faces.

What does FFA stand for?

Fusiform Face Area

What is the name of the main psychologist who argues that Prosopagnosia is NOT a face specific problem?

Gauthier et al (1999)

Which H can support Barton et al's 2002 study?

Hadjikhani et al (2003)

How can Jones' TA be criticized?

He had a covert ability to recognize faces - not face specific

What did Gauthier's finding suggest about Prosopagnosia?

It is not face specific, also involves object recognition difficulties

What does Hadjikhani's study suggest about the FFA?

It it inabilities within the FFA which may be a casual factor in Prosopagnosia

Give one weakness of Barton et al (2002)

Just because FFA is involved in recognizing faces, does not mean it is responsible. Cannot be certain damage to FFA has a direct causal effect, and so cannot say for sure it is the FFA damage causing Prosopagnosia.

What might faces being very similar to each other suggest about the abilities of people with prosopagnosia?

Lost ability to distinguish between very similar objects, rather than similar faces

Those with ASSOCIATIVE AGNOSIA have a.................deficit, because they cannot access relevant knowledge from memory to add meaning to stimulus

Memory deficit

The development of which two brain imaging techniques have allowed us to study brain functions during cognitive processes?

PET scans and fMRI scans

What approach does the explanations of Prosopagnosia take, and how can this be criticized?

Physiological approach Criticized for being biological reductionist - ignores psychological factors, maybe some individuals have psychological reasons for not wanting to identify faces or objects.

What conclusions can be brought from Gauthier's criticisms?

Prosopagnosia remains a face specific problem

Why does Barton's study support Prosopagnosia being face specific?

Suggests people process faces in a different area of the brain, and prosopagnosia is a specific problem with facial recogntion

How can Jones' TA support both facial and object recognition?

TA couldn't distinguish between mother/father and strangers, and also couldn't recognize objects in a category

What happened to participants in Gauthier et al's study?

Tested to see if they could recognize individual greebles

Why might some people have difficulty recognising faces?

They are very similar to eachother

How might the ethical issue of distress be overridden though?

They can opt out, and while giving consent, they are providing valuable insights into the causes.

Why can those with APPERCEPTIVE AGNOSIA be said to have a PERCEPTUAL DEFICIT?

They have no difficulty with memory or meaning, but cannot form a correct percept of a stimulus

Give one methodological strength of Barton et al (2002)

Used objective measurements in form of a brain scan, easier to be definite that it is FFA damage than just asking

What did Gauthier et al find out about participants?

Using the FFA to recognize the greebles, in the same way they use it to recognize faces

What does Prosopagnosia appear to be a failure of?

Visual and associative memories coming together to produce recognition

What have some researchers questioned about face recognition

Whether it is different from object recognition

What kind of brain scan did Hadjikhani (2003) use to support Barton? Who was used?

fMRI on people with Prosopagnosia and people without Prosopagnosia

How do some case studies support the nature debate?

some children are born with Prosopagnosia, supports suggestion we are born with some ability to recognise faces

How was Farah's study different from Barton and Hadjikhani's, and how can this be criticized?

used recognition test, not a brain scan (e.g. fMRI), so not as objective as Barton and Hadjkhani's studies, and cannot be sure if it was due to FFA damage