21.12 NS, Colour perception and motion

Question 1

Which layers do M and P cells terminate in?

Answer 1

M cells: layer 4Ca (inputs)

P cells: layer 4Cb (inputs)

Question 2

Where do M cells project to?

Answer 2

motion detection–>LGN–>4Ca–> (4B)

Question 3

What is directional selectivity? Where does this occur?

Answer 3

Some cells show orientation selectivity (motion direction), layer 4B

Question 4

How much of the cortex is involved in vision?

Answer 4

40%

Question 5

What are the 2 parallel visual streams indicating?

Answer 5

Dorsal (where)

Ventral (what)

Question 6

What area detects motion?

Answer 6

Dorsal stream, area MT (directionally/type selective)

Question 7

What are the different wavelengths that the cones respond to?

Answer 7

R: 560
G: 530
B: 430

Question 8

What happens when you shine a red light on the retina?

Answer 8

R cones: hyperpolarise (central)
ON bipolar cell: depolarises (Glutamate released)
ON ganglion: depolarises

Question 9

What happens when you shine a green light

Answer 9

G cones, hyperpolarise

HCs: hyperpolarise (less GABA release)

R cones: depol, Glut, hyperpolarisation

Question 10

What area is important for colour and shape perception?

Answer 10

Area V4 (input via V2)

Question 11

What are is important for facial recognition?

Answer 11

Area IT (output of V4)

Question 12

What do:
Protan
Deutan
Tritan
mean?

Answer 12

Protan: red
Deutan: green
Tritan: blue

Question 13

With regards to colour blindness, what does ‘nope’ or ‘nomal’ mean?

Answer 13

• nope: no xyz

- nomal: abnomal xyz

Question 14

What is anomalous trichromacy?

Answer 14

All three cones work, one expresses an abnormal pigment

Question 15

Neurons within V1 are….. ……?

Answer 15

directionally selective