Sem 4 Week 4 Lecture 3

Front 1

M ganglion cells ?

Back 1

-large diameter ganglion cells
-Wavelength insensitive

Front 2

M ganglion cells project to which layers of LGN ?

Back 2

Magnocellular layers of LGN--> layer IVC alpha-->layer IVB (of striate cortex)

Front 3

Cells within layer IVB are sensitive to ?

Back 3

-Orientation of a bar
-Direction in which a bar moves across the receptive field.

Front 4

Some cells in layer IVB are

Back 4

Direction selective.

Front 5

Layer IVB ?

Back 5

-some cells show orientation selectivity
-some cells show preference for direction of motion of target.

Front 6

What percent of cortex involved in vision?

Back 6

40

Front 7

Cortical visual system is composed of

Back 7

Multiple visual areas with diff. functions.

Front 8

What are the 2 large cortical systems of visual processing?

Back 8

-Dorsal (WHERE ?)
-Ventral(WHAT ?)

Front 9

DOrsal stream important for ?

Back 9

-Motion detection

Front 10

Ventral stream important for ?

Back 10

-Perception of colour and higher order recognition such as face recognition.

Front 11

Area MT is found in

Back 11

Dorsal stream.

Front 12

Area MT ?

Back 12

Region within middle temporal lobe specialized for detection and processing of object motion.

Front 13

Area MT receives input from where?

Back 13

-Retinotopic info from no. of cortical areas incl. V2 & V3
-layer IVB of primary visual cortex

Front 14

Area MT ?

Back 14

-neurons have large receptive fields
-respond to stimulus mvt
-almost all cells within area MT are direction selective

Front 15

Area MT respond to diff types of motion such as drifting spots of light.

Back 15

TRUE

Front 16

Area MT has

Back 16

Direction-of-motion columns

Front 17

Colour is defined by which 3 physical properties of light?

Back 17

-Wavelength
-Purity
-Intensity

Front 18

What is the tricolour theory ?

Back 18

A particular colour is determined by the ratio of excitation of a red,green or blue system.

Front 19

What did Hering propose ?

Back 19

The opponent response theory with red-green and blue-yellow opponent systems

Front 20

How many diff. types of cones are there?

Back 20

3

Front 21

What are they?

Back 21

3 diff types of cones with 3 diff. photopigments maximally sensitive to:-
-Long(RED) wavelength
-Medium(GREEN) wavelength
-Short(BLUE) wavelength

Front 22

3 corresponding percepts of colour ?

Back 22

-Hue:related to wavelength
-Saturation:how washed out the colour is.
-Brightness:Related to reflectance or luminosity.

Front 23

Mixing of red,green and blue light causes

Back 23

Equal activation of 3 types of cones-->perception is white.

Front 24

Colour vision is based on

Back 24

3 types of photreceptors each with diff spectral sensitivity & all colours encoded by relative activity of these 3 receptors.

Front 25

How do you get neural coding of colour?

Back 25

There are centre surround ganglion cells in which centres and surrounds are sensitive to diff. colours(blue/yellow and red/green single opponent cells)

Front 26

P ganglion cells exhibit

Back 26

Colour opponent centre-surround.

Front 27

Some P ganglion cells are excited by Red falling on their centre and inhibited by green following on the surround.

Back 27

True

Front 28

Colour perceived is determined by ?

Back 28

Activity of ganglion cells.

Front 29

M and P pathways feed into

Back 29

2 extrastriatal cortical pathways
-dorsal(motion and depth)
-ventral(contrast & contour;colour)

Front 30

Ventral extrastriate stream important for

Back 30

Colour perception

Front 31

Area V4

Back 31

-receives input from blob and interblob regions of primary visual cortex via V2
-important for shape and colour

Front 32

Neurons in V4 have

Back 32

large receptive fields that are both ORIENTATION selective and COLOUR selective.

Front 33

Area IT

Back 33

-major output of V4
-neurons respond to wide variety of abstract shapes and colours

Front 34

Area IT important for

Back 34

Visual memory and perception(of FACES)

Front 35

Few ppl are truly colour blind.

Back 35

True

Front 36

Colour vision deficiencies can be

Back 36

-Acquired
-Inherited

Front 37

Colour vision deficiencies in males and females?

Back 37

-8 % in males
-0.5 % in females

Front 38

Monochromacy

Back 38

Ppl have only one type of cone

Front 39

Dichromacy

Back 39

Sufferers have only 2 functional cones.

Front 40

Anomalous trichromacy

Back 40

Sufferers have all 3 cones but one expresses abnormal pigment and doesnt work the same as normal cones.

Front 41

What are the 3 types of colour inherited colour vision deficiencies ?

Back 41

-Protan
-Deutan
-Tritan

Front 42

Protanope

Back 42

No RED cone(person is dichromat)

Front 43

Protanomal

Back 43

Abnormal red cone

Front 44

Deutanope

Back 44

no GREEN cone

Front 45

Deutanomal

Back 45

Abnormal GREEN cone

Front 46

Tritanope

Back 46

no BLUE cone

Front 47

Tritanomal

Back 47

Abnormal BLUE cones