Chapter 10: Vision

Question 1

Vision

Answer 1

The detection of light in an environment.

Question 2

Light

Answer 2

Certain frequencies of electromagnetic waves.

Question 3

Pinhole Camera

Answer 3

Image gets converted as it passes through an aperture

Question 4

What serves a main importance in vision?

Answer 4

The shape of the eye

Question 5

Myopia

Answer 5

Eye is too long so the image surrounding the retina is blurred.

Question 6

How can myopia be resolved?

Answer 6

Glasses

Question 7

What two sides are the retina divided into?

Answer 7

1. temporal
2. nasal

Question 8

If the image hits the outer edge of the eye, it fields into the ___ side of the brain.

Answer 8

SAME

Question 9

If the image hits the inner edge of the eye, it fields into the ___ side of the brain.

Answer 9

OPPOSITE

Question 10

What side is the temporal retina on?

Answer 10

Left

Question 11

What side is the nasal retina on?

Answer 11

Right

Question 12

Are the things that the left and right eye see identical?

Answer 12

No

Question 13

What is the one type of cell in the retina that produces AP?

Answer 13

Ganglion cells

Question 14

Rods

Answer 14

-Work in dim light
- Black and white
(scotopic system)

Question 15

Cones

Answer 15

• Work in bright light
• differentiate between wavelengths of light
• Color
  -(photopic system)

Question 16

What are the 5 types of cells in the retina?

Answer 16

1. Photoreceptors (rods and cones)
2. Bipolar cells
3. Amacrine cells
4. Horizontal cells
5. Ganglion cells

Question 17

Retina

Answer 17

Large convergence of inputs outside the fovea (very little inside)

Question 18

What does your visual system respond to?

Answer 18

Changes in light

Question 19

Horizontal and Amacrine Cells

Answer 19

Very important for interactions with the retina

Question 20

Lateral Inhibition

Answer 20

Inhibitory connections between interneurons create a sharper border contrast.

Question 21

What is an example of horizontal and amacrine cells?

Answer 21

Lateral inhibition

Question 22

How does photoreceptor transduce light into neural signals?

Answer 22

Rods

Question 23

What is the pathway of light?

Answer 23

1. Light hyper polarizes neurons, which reduces neurotransmitter release
2. It breaks up retinal/rhodopsin, eventually leading to the closing of Na+ channels
3. The cascade of effects increase the sensitivity of cells
4. Information is integrated over time, leading to increased sensitivity but not as god temporal resolution.

Question 24

How do we handle a huge range in light intensity?

Answer 24

Pupils constrict/dilate

Question 25

Range Fractionation

Answer 25

Rods vs Cones

Question 26

Adaption

Answer 26

Cells themselves can adapt to ambient light

Question 27

Calcium ions

Answer 27

Cells that regulate intracellular levels, which alters neurons sensitivity

Question 28

What is needed for transduction?

Answer 28

Availability of chemicals

Question 29

What is sensitivity of the eye influenced by?

Answer 29

the ratio of rate of breakdown/recombination of retinal/rhodopsin.

Question 30

What do cones connect to?

Answer 30

Bipolar neurons

Question 31

How many types of bipolar cells are there?

Answer 31

2

Question 32

How do bipolar cells respond?

Answer 32

Oppositely when the cone hyper polarizes

Question 33

What receptor fields are used for bipolar cells?

Answer 33

On center and Off center

Question 34

What receptive field do ganglion and LGN cells have?

Answer 34

Concentric receptive fields

Question 35

On Surround pairs with

Answer 35

off center

Question 36

Off Surround pairs with

Answer 36

on center

Question 37

Parvocellular Cells

Answer 37

Small receptive fields, not responsive to different wavelengths.

Question 38

Magnocellular Cells

Answer 38

Large receptive fields, not responsive to different wavelengths.

Question 39

Ganglion cells can be labeled...

Answer 39

M or P (magnocellular or parvocellular)

Question 40

What do cortical cells require to respond?

Answer 40

specific stimuli

Question 41

Simple Cortical Cells

Answer 41

Respond to edge or bar with particular width, location, and orientation.

Question 42

Complex Cortical Cells

Answer 42

Elongated receptive fields, not as tied to location.

Question 43

High frequencies require ___ receptive fields.

Answer 43

small

Question 44

What cells are an example of high frequency?

Answer 44

Cells in the fovea (detail and sharp contrasts)

Question 45

Low frequency cells

Answer 45

Cells in the periphery with larger receptive fields

Question 46

What are low frequency cells more involved in?

Answer 46

Gradual transitions and large uniform areas.

Question 47

Where does visual information initially come from?

Answer 47

V1 region - layer IV cells

Question 48

V2 Region

Answer 48

Responsible for illusory contours (similar to V1 in processing)

Question 49

V4 Region

Answer 49

Receives input from V2 and responds to sinusoidal frequencies. - Concentric and radial stimuli

Question 50

V5 Area

Answer 50

Perception of Motor

Question 51

Inferior Temporal (IT)

Answer 51

Complex forms

Question 52

What is the Inferior Temporal apart of?

Answer 52

Prefrontal cortex = responds to faces

Question 53

Layer IV

Answer 53

Receives LGN input (molecular input)

Question 54

How do all layers except layer IV receive input?

Answer 54

binocularly

Question 55

How is the V1 cortex organized?

Answer 55

Columns (same ocular dominance through each)

Question 56

How are the columns linked together?

Answer 56

ocular dominance slabs

Question 57

Columns within the same region respond...

Answer 57

In the same way

Question 58

What is color constructed by?

Answer 58

Your visual system

Question 59

Trichromatic Hypothesis (Helmholtz)

Answer 59

Photoreceptors would have specific, defined wavelengths -they respond to 3 of them.

Question 60

What can photoreceptors not fully account for?

Answer 60

Color

Question 61

Opponent Process Theory

Answer 61

Opponent pairs of colors Red vs Green Blue vs Yellow Black vs White

Question 62

How do you get better color discrimination?

Answer 62

When colors oppose each other

Question 64

Why are these spectrally opposing cells so useful?

Answer 64

Cones show significant overlap (M and L cones have very close absorbance peaks)

Question 65

Region V4 is specifically important for...

Answer 65

Processing color

Question 66

What does processing color require?

Answer 66

Context (comparison with nearby colors)

Question 67

What type of vision is not widespread among mammals?

Answer 67

Trichromatic Vision (depends on the need of the animal)

Question 68

Dorsal stream processes...

Answer 68

Movement and location

Question 69

Ventral stream processes...

Answer 69

objects, faces, etc.

Question 70

Patient DF

Answer 70

Had CO2 poisoning and could not recognize objects/faces

Question 71

Patient DF had damage to...

Answer 71

Ventral stream, but not dorsal