Secondary visual association areas (areas 18 and 19)

Question 1

What are the secondary visual association areas?

Answer 1

areas 18 and 19

Question 2

How do the secondary visual association areas differ from the primary visual cortex anatomically?

Answer 2

they lack the characeristic extra stria found in primary visual cortex

Question 3

Where are the secondary visual association areas located?

Answer 3

lie above and below area 17, extend onto the lateral surfaces of the cerebral hemispheres

Question 4

What are the layers like in the visual asociation areas compared with the primary visual cortex?

Answer 4

there are the usually 6 layers

layer IV is less extensive

Question 5

What are 4 regions that areas 18 and 19 receive afferent input fibres from?

Answer 5

1. area 17
2. thalamus
3. pulvinar
4. other regions of cerebral cortex

Question 6

What structures do the connections of areas 18 and 19 mainly follow?

Answer 6

follow dorsal and venrtal pathways

Question 7

What is the role of outputs from the visual association areas to area 7 (parietal cortex)?

Answer 7

mainly involved in stereopsis and movement

Question 8

What is the role of ventral outputs from the visual association areas to the inferotemporal cortex?

Answer 8

concerned with analysis of colour and form

Question 9

What is the role of connections from the visual association areas to area 37 (temporal lobe)?

Answer 9

associated with recognition of faces

Question 10

What evidence is there that area 18 is lkely invovled in sensory-motor eye coordination?

Answer 10

because this is known to be linked to the frontal eye fields and oculomotor nuclei via descending pathways

Question 11

How are the visual association areas involved in integration of information?

Answer 11

integrate information from two halves of the visual field via commissural fibres crossing the midline in the splenium of the corpus callosum