Cortical processing of visual information

Question 1

What is the pathway from the optic nerve to the primary visual cortex?

Answer 1

Optic tract axons
LGN
Primary visual cortex

Question 2

What are the two visual pathways?

Answer 2

1.Ventral-
object recognition
final destination= inferior temporal lobe
2.Dorsal-
location stream
final destination= posterior parietal lobe

Question 3

What are the trends along the ventral stream? (V1 to temporal lobe)

Answer 3

1. Increase in complexity of responses of neurons

2. Increase in the receptive field size of neurons

Question 4

How many layers are there in the LGN?

Answer 4

6

Question 5

Where does 80% of LGN input come from?

Answer 5

The primary visual cortex (backwards)

Question 6

What are the 3 main structures found in the visual cortex?

Answer 6

Ocular dominance columns
Orientation columns
Blobs

Question 7

What are the 3 main cell types in the visual cortex?

Answer 7

1. Simple cells
2. Complex cells
3. Hypercomplex

Question 8

What is the difference between simple and complex cells?

Answer 8

Simple cells have distinct ON and OFF regions in their receptive fields
Complex cells give ON and OFF responses to stimuli throughout their receptive field

Question 9

What is the ‘grandmother cell’ idea?

Answer 9

Theory that there are 5-10 cells with receptive fields so highly defined that the cells respond only to 1 person
Location (?)- temporal lobe