Higher Visual Processing Flashcards Preview

MD1 Neuroscience > Higher Visual Processing > Flashcards

Flashcards in Higher Visual Processing Deck (53):
1

From where are the visual information streams segregated?

From retina to visual cortex

2

Is information from each eye mixed in the thalamus?

No

3

What type of information do M ganglion cells carry?

Motion

4

What type of information do P ganglion cells carry?

Colour

5

What is the input layer from the thalamus into sensory cortices?

Layer IV

6

In which layer of V1 do M cells terminate?

Layer IVC alpha (superior)

7

In which layer of V1 do P cells terminate?

Layer IVC beta (inferior)

8

Which layer of V1 is important for motion detection?

Layer IVB

9

From layer IVC, where does information go?

Other layers of V1

10

To what area do layers II, III, and IVB send their information?

Other cortical areas like
- V2, 3, 4, 5
- MT

11

To what area does layer V send its information?

Superior colliculus
Pons

12

To what area does layer VI send its information?

Lateral geniculate nucleus

13

What is the diameter of M ganglion cells?

Large

14

Are M ganglion cells wavelength sensitive?

No

15

To what part of the brain do M ganglion cells project?

Magnocellular layer of LGN

16

Where do M cells from the thalamus project to?

Layer IVC alpha of V1

17

Where do cells from layer IVC alpha project to?

Layer IVB of V1

18

Where does mixing of information from the two eyes occur?

In layer IVB of V1

19

What kind of selectivity do some cells have in layer IVB?

Orientation selectivity
Directional selectivity

20

How much of the cortex is involved in vision?

40%

21

What is the Brodmann's area of the secondary visual cortex (V2)?

Area 18

22

What are the two streams of visual processing?

Dorsal
Ventral

23

What does the dorsal pathway process?

Where; eg: movement

24

What does the ventral pathway process?

What; eg: object recognition

25

What is area MT?

In middle temporal lobe
Specialised for processing object motion

26

Where does MT receive information from?

Range of cortical areas including V2 and V3
Direct input also from layer IVB of V1

27

What is the size of the receptive fields in area MT?

Large

28

What do the receptive fields of area MT respond to?

Movement

29

What kind of selectivity do cells in area MT have?

Directional selectivity

30

What kind of columns does area MT have?

Direction of motion columns

31

What produces the perception of white light?

Equal activation of red, green, and blue cones

32

What allows the first response in the perception of colour?

Combined response of all 3 cones

33

What kind of receptor field do some P ganglion cells have?

Colour opponent centre-surround

34

Describe red ON-centre P ganglion cells

Centre responds to red
Surround responds to green

35

Describe blue ON-centre P ganglion cells

Centre responds to blue
Surround responds to yellow

36

Describe the receptive fields of neurons in V4

Large
Orientation selective
Colour selective

37

What is V4 important for?

Perception of shape and colour

38

Where is area IT?

In inferior temporal lobe

39

What do neurons in area IT respond to?

Wide variety of abstract shapes and colours

40

What is area IT important for?

Visual memory
Perception, especially of faces

41

Are colour deficiencies acquired or inherited?

Both

42

What proportion of males and females have colour blindness?

8% of males
0.5% of females

43

What is monochromacy?

Have only one type of cone - usually blue

44

What is dichromacy?

Have only two types of cones

45

What is anomalous trichromacy?

Have all three types of cones, but one expresses abnormal pigment and doesn't work the same as normal cones

46

What is protanope?

No red cone

47

What is protanomal?

Abnormal red cone

48

What is deutanope?

No green cone

49

What is deutanomal?

Abnormal green cone

50

What is tritanope?

No blue cone

51

What is tritanomal?

Abnormal blue cone

52

What does it mean to be colour blind?

Trouble dealing with colour in everyday life

53

How can you test for colour blindness?

Using pseudoisochromatic plates

Decks in MD1 Neuroscience Class (55):