Stimulus recognition

Question 1

What is the relay station before signals reach the primary visual cortex?

Answer 1

Lateral geniculate nucleus

Question 2

How many layers are there?

Answer 2

6 layers of grey matter

Question 3

What are layers 1 + 2?

Answer 3

Magnocellular layers

• Receive from rods
• Depth, movement, light change

Question 4

What are layers 3-6?

Answer 4

Parvocellular

• Cones (long & medium wavelengths)
• Colour and fine detail
• Response slow and sustained

Question 5

What does monocular input mean?

Answer 5

Receives input from ganglion cells in 1 eye only

Question 6

What kind of organisation is there in the LGN?

Answer 6

Retinotopic

Question 7

What do parvocellular cells sample?

Answer 7

HIgh resolution

Question 8

Magnocellular?

Answer 8

Motion and object position

Question 9

What is the LGN also callled?

Answer 9

Thalamic relay system

Question 10

What makes 1:1 connections?

Answer 10

Ganglion cell axons ==> projection neurons

Question 11

Where does info go after LGN?

Answer 11

V1 cortex

Question 12

What is the ventral stream pathway?

Answer 12

Pganglion==>LGN==>V1==>V2==>V4==>inferior temporal cortex

Question 13

What occurs if there are lesions in the inferior temporal cortex?

Answer 13

Decreases the ability to recognise objects

Question 14

What do occular dominance columns receive input from

Answer 14

just 1 eye

Question 15

How can occular dominance columns be shown experimentally?

Answer 15

Inject radioactive proline and its is eventually accepted into cortex and you get striated picture

Question 16

What do orientation columns do?

Answer 16

Respond to particular oritentation

Question 17

What do blob columns do?

Answer 17

process and discriminate info about colour

Question 18

What do blob columns recieve input from?

Answer 18

Parvocellular layers of the LGN

Question 19

What do simple cells respond to?

Answer 19

Respond to bar orientated in certain direction

Question 20

Where are simple cells located?

Answer 20

layers 4+6

Question 21

What are the receptive fields like for simple cells?

Answer 21

Elongated

Question 22

What is the difference between a complex cell and a simple cell?

Answer 22

A complex cell responds to a bar in a certain orientation positioned anywhere in the receptive field

Question 23

Which layers are complex cells located?

Answer 23

2, 3, 5

Question 24

What may complex cells receive input from?

Answer 24

Many simple cells

Question 25

How does a hypercomplex cell work?

Answer 25

Respond to certain orientation of bar if the stimulus goes away from the receptive field the cell stops responding. But if the bar changes orientation outside of receptive field it starts responding again

Question 26

Where are simple cells located and where do they send signals?

Answer 26

4+6 and send info to 2+3

Question 27

What do inferior temporal lobe neurons respond to?

Answer 27

faces

Question 28

What is the jennifer aniston neuron?

Answer 28

Idea that an object is represented by a large population of cells - population coding model

Question 29

How is the info bottleneck of the optic nerve dealt with?

Answer 29

Retina rejects unimportant info

Question 30

In darkness, what will be the state of on-bipolar cells in the fovea, and which receptors mediate this?

Answer 30

hyperpolarised, metabotropic glutamate receptors

Question 31

What is the difference between type I afferents and type II afferents from the cochlea?

Answer 31

A type II afferents turn basally to innervate high frequency outer hair cells

Question 32

What can be said of neurons further along the object recognition pathway?

Answer 32

receptive fields grow and responses become more complex