Vision

Question 1

Cornea

Answer 1

Refracts light at the retina

Question 2

Lens

Answer 2

Changes shape to fine-tune the image and further refract light towards the retina

Question 3

Rods

Answer 3

More common and see in the dark

Question 4

Cones

Answer 4

Less common but high acuity and see in the day

Question 5

Horizontal cells

Answer 5

Contact photoreceptors and bipolar cells

Question 7

Amacrine cells

Answer 7

Contact bipolar and ganglion cells

Question 8

Order of visual processing

Answer 8

Rods/cones> bipolar cells> ganglion cells> optic nerve

Question 9

Fovea

Answer 9

Centre region of the retina that has a high density of smaller, tightly packed cones with high acuity

Question 10

Retina

Answer 10

A layer of neurons at the back of the eye

Question 11

Optic nerve

Answer 11

the collec­tion of ganglion cell axons that extends from the retina to the occipital cortex of the brain.

Question 12

Optic chiasm

Answer 12

The point at which parts of the two optic nerves cross the midline.

Question 13

Optic tract

Answer 13

The axons of retinal ganglion cells (form optic nerve) after they have passed the optic chiasm. Most of these axons terminate in the lateral geniculate nucleus.

Question 14

V1

Answer 14

Where most visual information arrives first

Question 15

V2

Answer 15

Adjacent to V1, can respond to illusory boundaries and complex relations among parts of the receptive field4

Question 16

V4

Answer 16

Strong responses to the frequency gratings

Question 17

V5

Answer 17

Specialized for the perception of motion and its direction

Question 18

On-centre receptive field

Answer 18

Light hits the cone and causes glutamate release to decrease, depolarizing the on-centre bipolar cell and increasing its neurotransmitter release. This goes to the on-centre ganglion cell which increases its firing rate.

Question 19

Off-centre receptive field

Answer 19

Light hits the cone and causes glutamate release to decrease, hyperpolarizing the off-centre bipolar cell and decreasing its neurotransmitter release. This goes to the off-centre ganglion cell which decreases its firing rate.

Question 20

Hubel & Wiesel’s theoretical model of visual analysis

Answer 20

Is hierarchical.

More complex receptive fields are built up from inputs of simpler ones.

Question 21

Visual acuity

Answer 21

Sharpness of vision

Question 22

Adaptation

Answer 22

Each photoreceptor adjusts its level of sensitivity to match the average ambient level of light.

Question 23

Lateral inhibition

Answer 23

The phenomenon by which interconnected neurons inhibit
their neighbours, producing contrast at the edges of regions.

Question 24

Trichromatic hypothesis

Answer 24

Three different types of cones (RGB) that each respond to a specific part of the spectrum. Each has its own separate pathway to the brain and color is recognized based on which receptors are activated.

Question 25

Opponent-process hypothesis

Answer 25

Four unique hues (blue, green, yellow, red) and three opposed pairs of colours (b&y, g&r, b&w).

Question 26

Dorsal stream

Answer 26

Assessing the location of objects (where) and guiding our movements towards them

Question 27

Ventral stream

Answer 27

Identifying objects (what)

Question 28

Rhodopsin

Answer 28

The photopigment in rods that responds to light.

Question 29

Lateral geniculate nucleus (LGN)

Answer 29

The part of the thalamus that receives information from the optic tract and sends it to visual areas in the occipital cortex.

Question 30

on-center bipolar cell

Answer 30

A retinal bipolar cell that is excited by light in the center of its receptive field. know how they work

Question 31

off-center bipolar cell

Answer 31

A retinal bipolar cell that is inhibited by light in the center of its receptive field.

Question 32

on-center ganglion cell

Answer 32

A retinal ganglion cell that is activated when light is presented to the center, rather than the periphery, of the cell’s receptive field.

Question 33

off-center ganglion cell

Answer 33

A retinal ganglion cell that is activated when light is presented to the periphery, rather than the center, of the cell’s receptive field.

Question 34

Amblyopia

Answer 34

Reduced visual acuity not caused by optical or retinal damage

Question 35

Optic ataxia

Answer 35

Difficulty using vision to reach for and grasp objects

Question 36

Simple cortical cells

Answer 36

"Bar detectors" respond to edge or bars of a particular width that is in a specific location in the visual field

Question 37

Complex cortical cells

Answer 37

Responds best to bar of a particular width that is in motion anywhere in the field

Question 38

Lateral inhibition

Answer 38

Sensory receptor cells inhibit information from the neighbouring receptor cells

Question 39

Scotopic system

Answer 39

Rods

Question 40

Photopic system

Answer 40

Cones

Question 41

Myopia (nearsightedness)

Answer 41

Difficulty seeing distant objects