W4: Parallel Visual Pathways

Question 1

What is disparity and it’s use?

Answer 1

For a far object, image lands to the right of the left fovea and left of the right fovea.
Selectivity for the difference in position between the eyes is called disparity sensitivity used in depth perception

Question 2

Describe and explain the structure of V2 with V1 outputs

Answer 2

4B from V1 into thick V2 stripes for movement direction and disparity

2/3 inter-blobs from V1 into pale V2 stripes for real/illusory orientation and contrast

2/3 blobs from V1 into thin V2 stripes for colour and contrast

Question 3

Describe the Ventral pathway

Answer 3

V1 (2/3) to V2 (pale/thin stripes) to
V4 (complex form and colour) to
Inferotemporal Cortex (facial expressions/body language)

Question 4

Describe the Dorsal pathway

Answer 4

V1 (4b) to V2 (thick stripes) to
V3 (depth processing) to

V5: associates multiple motion signals with motion of multi-limbed object, projects to

Medial Superior Temporal cortex processes optic flow to Inferior Parietal Lobule: translates visual space to motor space to guide movement

Question 5

Describe the infero-temporal cortex and it’s importance in survival

Answer 5

Large receptive fields respond to face/hand components for expressions/body language and identifies what is human

Question 6

Describe the Inferior Parietal Lobule

Answer 6

7a: cells active when eye moves to target
Lateral Intra Parietal cortex: keeps memory trace with connections to frontal eye fields

Question 7

Describe Frontal Eye Fields

Answer 7

Has memory and is linked to the superior colliculus for eye movement

Question 8

Describe the medial superior temporal cortex

Answer 8

Process optic flow (movement of the visual field) to the intra parietal lobule

Question 9

Name 2 visual pathway problems

Answer 9

Dorsal: Optical Ataxia issues locating object
Ventral: prosopagnosia (face blindness)