Extrastriate cortical areas

Question 1

Difference between V1 and V2-V5

Answer 1

V1:
Small receptive fields
Respond to local properties: orientation, length, width, speed, direction

V2-V5:
large receptive fields. Responds to global properties. Color, shape.

Question 2

V2

Answer 2

Stripes appear perpendicular to v1/v2 border.

Thick stripes. M cell pathway. Input from 4C alpha. Output to V3 and V5. Orientation, motion, binocular disparity.

Thin stripes. P cell–> 4C beta –> blobs. Input from blobs. Output to V3, V4, V5. orientation, and binocular disparity.

pale stripes. P cell –> Interblob. Input from layers 2 and 3 (everything except blobs). Output to V4. Orientation and binocular disparity.

Question 3

V3.

Answer 3

Receives M and P cell info from V2. Integrates motion and color. Output to V5 and parietal cortex.

V3A only sends output to parietal cortex.

Question 4

V4

Answer 4

Major input form parvocellular path. Blob and inter blob. Perception of color and form.
Damage here = loss of color vision.

Question 5

V5

Answer 5

Major input from magnocellular pathway. Motion. Damange= motion blindness. Akinetopsia.

Question 6

Ventral stream

Answer 6

Ventral= side of head= parvo = what =
V1–V2–V4–IT
Largely parvo input. Some konio
Damage causes inability to recognize familiar objects or faces.

Question 7

Dorsal stream

Answer 7

Dorsal= top of head= margo= motion
V1–V2–V3–V5–Lateral parietal area of 7A– Frontal eye fields
Damage causes inability to see motion