Sensory Systems - General & Visual

Question 1

sensory receptors do what

Answer 1

they convert sensory energy into neural activity

Question 2

which senses have sensory receptors

Answer 2

all 5 senses

Question 3

receptors are energy ______

Answer 3

filters, they respond only to a narrow band of energy

Question 4

for vision, it converts what into what

Answer 4

converts light rays into chemical energy in the photoreceptors, which is then converted into action potentials

Question 5

for taste and smell, it converts what into what

Answer 5

converts chemical energy into action potentials

Question 6

for audition, converts what into what

Answer 6

air pressure waves into mechanical energy which activates auditory receptors which produces action potentials

Question 7

for somatosensory, converts what into what

Answer 7

mechanical energy activates mechanoreceptors which produce action potentials

Question 8

pathway w receptor for touch sensation

Answer 8

touch - displacement of hair
- causes stretch sensitive channels on dendrite to open, allowing an influx of Na+
- Influx of Na+ causes voltage-gated Na+ and K+ channels to open, producing a nerve impulse

Question 9

what is the receptive field

Answer 9

specific part of the world to which a sensory receptor responds
- for eyes, what you can see
- for hearing, 20 - 20000 Hz

Question 10

higher density of sensory receptors leads to

Answer 10

increased sensitivity
- ex: two point sensitivity (getting poked with two things, but in some low sensitivity areas it feels like just one poker)

Question 11

what are neural relays

Answer 11

All receptors connect to the cortex through a sequence of three or four intervening neurons
- spots where sensory systems can interact w eachother and the motor system

Question 12

what is the mcgurk effect, what concept does it relate to

Answer 12

what we see overrides what we hear
- if you can’t see the lips of someone when they speak, it can sound like they’re saying something else, even with the exact same audio
- relates to interaction of sensory systems at neural relays
- includes the vision and hearing systems

Question 13

which sense does not go through the thalamus

Answer 13

smell

Question 14

Sensory Information is Encoded by

Answer 14

action potentials

Question 15

what transmits info about stimuli after transduction

Answer 15

action potentials

Question 16

each sensory system is composed of

Answer 16

subsystems with distinct functions

Question 17

sensory systems have one ______ cortical area, and additional ________ areas

Answer 17

primary; secondary

Question 18

what do secondary areas do

Answer 18

perform specific tasks required for perception

Question 19

topographic organization of sensory systems

Answer 19

neural-spatial representation of the body or of areas in the sensory world that a sensory organ detects

for hearing: tonotopic map, different sound frequencies are represented in order along the cochlea and cortex.

for vision: retinotopic map, neighboring areas of the retina project to neighboring neurons in the visual cortex.
for somatosensory: body surface on body and homonculus

Question 20

hearing has ____ pathways and _____ pathways

Answer 20

“what” pathways and “where” pathways

Question 21

what lobe is motor info in

Answer 21

frontal

Question 22

what lobe is body senses located in

Answer 22

parietal

Question 23

what lobe is vision located in

Answer 23

occipital

Question 24

what lobe is hearing located in

Answer 24

temporal

Question 25

what aspects does the visual system pick up

Answer 25

general visual form, location, movement

Question 26

where are the primary and secondary areas for smell and taste

Answer 26

smell: buried in frontal lobe by the insula Taste - ventral surface

Question 27

sensory receptors of vision

Answer 27

photoreceptors

Question 28

location of photoreceptors

Answer 28

retina

Question 29

2 types of photo receptors

Answer 29

rods and cones

Question 30

rods - sensitive to what - located where

Answer 30

dim light, night vision peripheral retina

Question 31

why at night time, is it better to not look directly at something

Answer 31

because the rods, which are sensitive to dim light, are on the periphery of the retina

Question 32

cones

Answer 32

sensitive to bright light - day and colour vision densely packed in the fovea (in the center)

Question 33

cones or rods for dim light

Answer 33

rods

Question 34

cones or rods for bright light

Answer 34

cones

Question 35

what synapses with the rods/cones

Answer 35

bipolar cells/neurons

Question 36

where do bipolar cells/neurons send info to

Answer 36

ganglion cells

Question 37

where do ganglion cells/neurons go to

Answer 37

send axons to the brain axons form the optic nerve (CN2)

Question 38

what axons form the optic nerve CN2

Answer 38

ganglion cells/neurons axons

Question 39

difference between sensation and perception

Answer 39

perception is our interpretation of sensations

Question 40

do our sensory receptors respond to a large band of energy in the energy spectrum

Answer 40

no, our sensory receptors respond to only a narrow band of energy (ex. 20 - 20000 Hz for hearing) ex: dogs hearing sounds we cant hear

Question 41

our sensory systems ______ physical or chemical energy into ____ ________

Answer 41

transduce; action potentials

Question 42

each sensory system has a ______ field

Answer 42

receptive

Question 43

receptor ______ determines sensitivity

Answer 43

density

Question 44

what encodes a stimulus intensity

Answer 44

the amount of increase or decrease in a neuron's discharge rate

Question 45

how much does the cornea bend the rays

Answer 45

slightly

Question 46

how much does the lens bend the light; what else does it do

Answer 46

to a much greater degree than the cornea, and also inverts it upside down and backward, and focuses it onto the receptors in the back of the eye

Question 47

pathway of light throw the eyeball

Answer 47

through the cornea and light is refracted a bit, then through the lens and even more refraction occurs and the image is inverted upside down and backward, and then onto the receptors at the back of the eye

Question 48

2 main visual pathways

Answer 48

Geniculostriate Pathway & Tectopulvinar Pathway

Question 49

lead up to the 2 visual pathways (flow after the light enters the eyes)

Answer 49

Optic nerves leave each eye and cross at the optic chiasm, but only half of fibers (nasal ½) from each eye cross. - The right half of each eye's visual field is represented in the left hemisphere, the left half of each eye's visual field is represented in the right hemisphere. - Now they are in the brain proper, the optic tract now diverges into 2 main pathways

Question 50

info from the right half of the visual field falls on the _____ half of the retinas and ends up in the ____ hemisphere

Answer 50

left; left

Question 51

left visual field = ____ side of the eye = ____ side of the brain

Answer 51

right; right

Question 52

which visual pathway first goes through the thalamus in their pathway

Answer 52

geniculostriate pathway

Question 53

which visual pathway goes through the superior colliculi of the midbrain first

Answer 53

tectopulvinar pathway

Question 54

steps of the geniculostriate pathway

Answer 54

optic tract goes to the lateral geniculate nucleus of the thalamus, then to the primary visual cortex (aka striate cortex) in the occipital lobe

Question 55

what does the geniculostriate pathway take part in

Answer 55

pattern recognition and conscious visual functions - responsible for what we think of as vision

Question 56

which visual pathway is the what pathway, which is the where

Answer 56

geniculostriate pathway = what tectopulvinar pathway = where

Question 57

how is the visual field represented in the primary visual cortex (aka striate cortex, aka V1)

Answer 57

retinoptic map of the visual field represented in V1, but upside down, inverted (same inversion seen in eyeball), and reversed (right field to left hemisphere).

Question 58

info from right and left visual fields is ____________ in primary visual cortex

Answer 58

contralateral

Question 59

where does the optic nerve cross

Answer 59

optic chiasm (but remember its only half of their fibres)

Question 60

where is the central part of visual field represented

Answer 60

peripheral visual cortex

Question 61

where is the periphery of the visual field represented

Answer 61

medially

Question 62

where is the upper part of the visual field represented

Answer 62

below the *calcarine fissure* at the middle of the occipital lobe

Question 63

where is the lower part of the visual field represented

Answer 63

above the *calcarine fissure*

Question 64

what seperates the representaion of the upper and lower part of the visual field in the V1

Answer 64

the calcarine fissure

Question 65

would above or below the calcarine fissure in V1 present us with a distal view of the space we move in; which shows a proximal view of our hands

Answer 65

below - distal view (space) above - proximal view (hands)

Question 66

tectopulvinar pathway steps

Answer 66

optic tract goes to superior colliculi in midbrain tectum, then through the posterior-pulvinar complex of the thalamus, does NOT go to primary visual cortex; goes to other visual areas in temporal and parietal lobes

Question 67

what is anopsia; what causes it

Answer 67

visual field deficits after stroke - damage to temporal lobe where pathways (like geniculostriate pathway) pass through - could be complete or partial depending on the amount of damage

Question 68

what does the tectopulvinar pathway detect

Answer 68

Detects stimuli in space, detects movement and helps us orient to stimuli

Question 69

how many intervening neurons for vision, hearing, and somatosensory

Answer 69

3 for vision, 4 for hearing and somat

Question 70

what forms the auditory nerve

Answer 70

Axons of hair cell form auditory nerve

Question 71

what are the first signs of huntington's disease

Answer 71

Psychological or behavioural changes

Question 72

order of sensory info in posterior parietal cortex for motor planning

Answer 72

Proprioception first, then hapsis, vision, and auditory

Question 73

what directly causes AP's in audition

Answer 73

bending of outer hair cells generates electrical actiivty - axons of these outer hair cells form CN 8

Question 74

in vision, where are the action potentials forming

Answer 74

ganglion cells; bipolar cells induce action potentials in retinal ganglion cells (RGCs)

Question 75

optic nerve formed from what

Answer 75

axons of ganglion cells