Module 3 - Vision

Question 1

4 sensory systems

Answer 1

olfactory, audition, visual, and somatosensory

Question 2

what are sensory receptors

Answer 2

transduce energy from environment into neural activity

Question 3

receptive field

Answer 3

a sensory space in which a stimulus modifies a receptor’s activity

produces patterns/maps

brain uses to identify sensory info

Question 4

neural relays

Answer 4

the idea that receptors connect to cortex through sequence of connecting neurons sharing information

Question 5

sensory coding

Answer 5

after being transduce, information from sensory systems is encoded by action potentials that travel along nerves until entering spinal cord/brain

Question 6

topographic map

Answer 6

neural-spatial representation of sensory world

Question 7

what part of electromagnetic spectrum can humans see

Answer 7

visual light (400-700nm)

Question 8

sclera

Answer 8

the white of the eye

Question 9

cornea

Answer 9

clear outer covering

bends light upon entering the eye

Question 10

iris

Answer 10

colored area of eye

opens/closes to allow light in through the pupil

Question 11

pupil

Answer 11

black part of eye where light enters

Question 12

lens

Answer 12

focuses and bends light after the cornea

Question 13

retina

Answer 13

where light energy initiates neural activity

Question 14

fovea

Answer 14

the centre of there retina

high density of photoreceptors specialized for color

specialized for high visual acuity

Question 15

optic disc

Answer 15

where blood vessels enter the eye

where nerves from optic nerve leave the eye

no receptors and is where blind spot is located

Question 16

blind spot

Answer 16

no receptors

in optic disc

location is different in each eye - right eye can see left eye’s blind spot and vice versa

Question 17

myopia

Answer 17

nearsightedness

cannot see far away things

light falls short of retina

Question 18

hyperopia

Answer 18

farsightedness

cannot see close things

light falls beyond retina

Question 19

2 main types of retinal neurons

Answer 19

bipolar and ganglion cells

Question 20

characteristics of retinal neurons

Answer 20

translucent, not light sensitive, located at the front of retina

Question 21

2 types of photoreceptors

Answer 21

rods and cones

Question 22

characteristics of photoreceptors

Answer 22

located at back of eye, work with retinal neurons to translate light into action potentials, discriminate wavelengths to create colours etc.

Question 23

characteristics of rods

Answer 23

low light specialization

more numerous than cones

longer and cylindrical

Question 24

characteristics of cones

Answer 24

responsive to low light

less numerous than cones

specialized for colour and high visual acuity

Question 25

three types of cones

Answer 25

s cones (small = blue light) m cones (medium = green light) l cones (long = red light)

Question 26

two types of retinal ganglion cells

Answer 26

m cells and p cells

Question 27

characteristics of m cells

Answer 27

large receive input from rods sensitive to light, not color found throughout retina and periphery sensitive to movement

Question 28

characteristics of p cells

Answer 28

small, found mostly in fovea receive in put from cones sensitive to color, not light sensitive to differences in form

Question 29

optic chiasm

Answer 29

junction of optic nerves where the optic nerves cross before entering the brain after exiting each eye

Question 30

three pathways from retina to lobes in brain

Answer 30

geniculostriate system tectopulvinar system retinohypothalamic tract

Question 31

two possible streams to lobes after apthways

Answer 31

dorsal (parietal lobe) and ventral (temporal lobe)

Question 32

visual field

Answer 32

what is seen by the eyes divided into right and left visual fields input from right visual field goes into left hemisphere and vice versa

Question 33

how is neural excitation demonstrated

Answer 33

an increase in firing

Question 34

how is neural inhibition demonstrated

Answer 34

a decrease in firing

Question 35

where is shape constructed

Answer 35

in the cortex from information that ganglion cells pass on about events in their receptive fields

Question 36

why is shape not constructed in retina

Answer 36

receptive fields are too small