Agnosia and Prosopagnosia

Question 1

Agnosia is when … fails?

Answer 1

Object recognition

Question 2

Agnosia occurs after damage to what areas of the brain?

Answer 2

Occipital or inferior temporal cortex

Question 3

Summarise Apperceptive agnosia

Answer 3

1. Able to move about and negotiate obstacles without difficulty
2. Low-level binding of features appears to be absent (find really hard to combine features in order to create letter)
3. unable to perform basic copying and matching tasks
4. Damage to stage 2 of model

Question 4

Summarise Associative agnosia

Answer 4

1. Copying and matching skills unimpaired
2. patient unable to name object despite intact knowledge (can draw key, talk about key if verbally asked what it is, but if asked to name picture don’t know what it is)
3. Involves failure in accessing knowledge about objects
4. Damage to stage 3 of model

Question 5

What is prosopagnosia?

Answer 5

Loss in ability to recognise faces. Unable to recognise previously familiar faces via visual input but recognition by other modalities remains intact, meaning individuals can be recognised by their voices

Question 6

Damage to what area of the brain results in prosopagnosia?

Answer 6

Right inferotemporal lesion

Question 7

What is capgras delusion?

Answer 7

Recognition without feeling - recognise a face and yet deny the identity of the person. Recognise the face looks identical to the person they know, but the skin conductance is absent - have lost the emotional contact. Won’t interact with the person as think they’re an imposter

Question 8

How is the dorsal route linked to capgras delusion

Answer 8

Emotional context - you can have an emotional response to everything including home, this is why capgras think they’re not in their real home as emotional context lost

Question 9

Compare the routes of recognition in prosopagnosia and capgras delusion

Answer 9

Dorsal route through superior temporal sulcus and inferior parietal lobe (Capgras)
Overt ventral stream (Prosopagnosia)