Object recognition (Chris)

Question 1

What are the 2 visual systems?

Answer 1

Ventral

Dorsal

Question 2

Where is the ventral pathway located?

Answer 2

The lower pathway in the parietal lobe (temporal cortex)

Question 3

Where is the dorsal pathway located?

Answer 3

The upper pathway located in the occipital/temporal lobe (parietal cortex)

Question 4

What is the function of the ventral pathway and where does this activation occur?

Answer 4

Processes the identity of objects + discriminates between then. Vision for perception

Greater activation in primary fusiform gyrus

Question 5

What is the function of the dorsal pathway?

Answer 5

Involved in processing where objects are - spatial recognition = elevated activation in the dorsal pathway

Question 6

What happens if the dorsal pathway experiences lesions?

Answer 6

Deficits in spatial awareness (hemispatial neglect)

Question 7

What is visual agnosia? (Caused by lesions of the ventral pathway)

Answer 7

Impairment in visual perception but above the level of a basic sensory deficit. Difficulty discriminating sample visual stimuli and can’t recognise simple shapes such as triangles + circles.

Question 8

What is associative agnosia?

Answer 8

Have basic perception but can’t recognise properly e.g., can describe a picture of a dog and say it ‘barks and is a ‘pet’ but can’t say that it’s a dog - loss of understanding.

Question 9

What is prospagnosia?

Answer 9

Selective deficit in recognition of faces

Question 10

What is the role of the primary visual cortex (V1)?

Answer 10

Involved in correspondence between spatial structure of the PVC and spatial structure of the real world.

Question 11

Which area produces visual motion?

Answer 11

The MT - within the ventral visual pathway

Question 12

What did fMRI reveal about the lateral occipital complex? (LOC)

Answer 12

Seems to encode higher level representations of shape, even when not purely by retinal input

Question 13

How has fMRI helped understand object recognition?

Answer 13

Can investigate the sensitivity of neurons and whether the specific neurons adapt to identify an object.

Question 14

What did Vuilleumier et al (2002) find using fMRI?

Answer 14

Found a region in the left fusiform cortex that represents objects - this region is sensitive to object identify regardless of viewpoint.

Also revealed a region in the medial temporal lobe representing objects by their function