Disorders of object recognition

Question 1

List 5 reasons why people might fail to recognise objects

Answer 1

Sensory deficity eg acuity, field cut, loss of colour vision
Knowledge deficit- Alzheimer’s
Name (language deficit)- anomia

Question 2

What is agnosia?

Answer 2

able to draw from memory, define something, identify by touch BUT cant recognise object

Question 3

What is optic ataxia

Answer 3

patients have trouble reaching for an object, adjusting their grasp

• recognition is normal
• example of double dissociation

Question 4

visual agnosia and optic ataxia arise from problems where..

Answer 4

VA = vent stream to inf temporal lobe 
OA = dorsal stream projecting to parietal lobe

Question 5

Describe apperceptive agnosia

Answer 5

DF cant put edges of the object together / work out whats background or shadows. cant fill in fragments of pictures or cant see pics if they overlap

edge grouping, feature binding, view normalisation

Question 6

describe associative agnosia

Answer 6

GS can see the whole form of the shape but cant recognise the object - can copy objects down etc but cant name them

failure to access semantic representation

Question 7

Which one has unconscious awareness of action and what is it?

Answer 7

GS given a picture of a lock, he cant name it but subconsciously twirls his fingers in the motion of unlocking a lock

Question 8

associative and apperceptive which is which patient

Answer 8

GS - associative

DF - apperceptive