Selective deficit

Question 1

Apperceptive Agnosia

Answer 1

Right hemisphere ; occipital/temporal;/parietal lesions

Usually quite diffuse, due to CO damage / lack of oxygen

Patients see individual features but can’t integrate into a whole, failure of perceptual organization

Gollin picutre task (degraded pictures/letters) and copying is bad

Unusual (non-accidental) view/shading task is bad

Question 2

Integrative Agnosia

Answer 2

Similar to apperceptive but

• Copying is somewhat intact (copy very illogically but are able: piecemeal copying)
• Unusual views variable (some can come can’t)
• Overlapping objects are not seen individually

Question 3

Face recognition

Answer 3

Still intact, first support in idea that ‘faces are special’. In the vegetable picture, they can see the face but not that its made up of vegetables

Feedforward sweep seems to function normally in both conditions, but they can’t make sense of the combination of the features

Question 4

Prosopagnosia

Answer 4

Face selective neuropsychological deficit
- After extensive bilateral or right sided lesions in temporal and occipital lobes

Question 5

Double dissociation

Answer 5

Considered the best evidence for specialized neural module;
Lesion X = deficit in A not in B
Lesion Y = deficit in B not in A

Eg apperceptive/integrative agnosia and prosopagnosia

Against;
- Comparing between category with within category; First recognize category, than the difference

For:
- Farah: Within category better in faces than objects in ‘normal’ people, same in prosopagnostics
- Face inversion efffect (Tatcher illusion)