Extrastriate cortical areas Flashcards
Difference between V1 and V2-V5
V1:
Small receptive fields
Respond to local properties: orientation, length, width, speed, direction
V2-V5:
large receptive fields. Responds to global properties. Color, shape.
V2
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.
V3.
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.
V4
Major input form parvocellular path. Blob and inter blob. Perception of color and form.
Damage here = loss of color vision.
V5
Major input from magnocellular pathway. Motion. Damange= motion blindness. Akinetopsia.
Ventral stream
Ventral= side of head= parvo = what =
V1–V2–V4–IT
Largely parvo input. Some konio
Damage causes inability to recognize familiar objects or faces.
Dorsal stream
Dorsal= top of head= margo= motion
V1–V2–V3–V5–Lateral parietal area of 7A– Frontal eye fields
Damage causes inability to see motion