Section 3b: Vestibular and Vision

Question 1

what does the vestibular system do?

Answer 1

detects head acceleration be determining the head movement and position

Question 2

what components detect what?

Answer 2

otoliths (end organs)
- saccule: linear vertical acceleration
- urticle: linear horizontal acceleration
semicircular canals: angular acceleration

all based on the head

Question 3

what is roll, pitch & yaw

Answer 3

x, y and z oration axis

Question 4

how are otoliths and how do they convert head motion to electrical signals

Answer 4

cochlea and by deflection of hairs

Question 5

describe how the semicircular canals turn signal into angular acceleration

Answer 5

the canals are filled with a thick liquid called endolymph
when the head moves, the endolymph move in that direction (lag) and will push the hairs causing depolarization in one ear and hyperpolarization in another (depending on direction) which signal the motion

Question 6

what side does the kinocilium face in the right ear

Answer 6

the kinocilium is on the left (like thumb on RIGHT HAND)

Question 7

what side does the kinocilium face in the left ear

Answer 7

the kinocilium is on the right (like thumb on LEFT HAND)

Question 8

what causes the kinocilium to cause depolarization

Answer 8

all the hairs falling on it (kinocilium is thumb)

Question 9

what happens in semicircular canals when I turn my head in one direction (left or right)

Answer 9

the endolymph moves in the opposite direction or the head turn
example: turning left makes the liquid go right
the left ear will start signalling as the hairs as moving right causing depolarization
the right ear will stop signalling as the hairs are turning right causing hyperpolarization

Question 10

basic way of figuring out which ear will depolarize

Answer 10

direction of head turn causes depilation in that ear
head rate left= left ear depolarize

Question 11

describe how the otolith signal head acceleration

Answer 11

otolithic stones on top of hairs that move you hairs in the direction your head moves
(forward is depolarization )

Question 12

what are the 4 functions of the vestibular system

Answer 12

• maintenance of balance
• gaze stabilization: vestibular ocular reflex (VOR)
• perception of self-motion: head motions tells CNS
• spatial navigation/oritenation

Question 13

what is VOR

Answer 13

vestibular ocular reflex: eyes rotate to maintain target when head moves

Question 14

what is the galvanic vestibular stimulation?

Answer 14

its when electrodes are placed behind your ears
anodes stimulation: decreased sway
cathode stimulation: increased sway
sway always toward anode (+)

Question 15

how much refraction occurs at cornea and lens

Answer 15

2/3 cornea and 1/3 lens

Question 16

what is the fovea?

Answer 16

part of the retina that allows vision of fine details and only contains cones

Question 17

what pigment does the fovea lay on and why

Answer 17

melanin so it can absorb any light not captured by the photo receptors

Question 18

what is the vision field

Answer 18

the region of space that can be seen by the full rotation of eyeballs

Question 19

what are the 2 parts of the vision field?

Answer 19

central and peripheral

Question 20

what is peripheral vision?

Answer 20

deals where things are
- environmental context and moving limbs
- mostly rods and sparse cones used

Question 21

what is central vision?

Answer 21

deals with identifying details
- central 5 dares of field
- mostly cones

Question 22

what is the nasal hemiretina

Answer 22

the retinas on either side of your nose

Question 23

what is the temporal hemiretina

Answer 23

the retinas by ur ears

Question 24

what can the left side of the left eyeball see?

Answer 24

right side of the middle view (right nasal vision)

Question 25

what can the right side of the left eyeball see?

Answer 25

temporal left of left field (left temporal)

Question 26

what can the left side of the right eyeball see?

Answer 26

temporal right of right field (right temporal)

Question 27

what can the right side of the right eyeball see?

Answer 27

left of middle view (left nasal)

Question 28

basic explanation of what the eyes see

Answer 28

the nasal hemiretinas see the temporal side of the opposite side the temporal hemiretinas see the middle side of the opposite side

Question 29

how are the optic nerves connected

Answer 29

right side of both eyes report to the right optic nerve left side of both eyes report to the left optic nerve

Question 30

what hemiretinas pass the optic chiasm

Answer 30

nasal hemiretinas

Question 31

what happens if the left optic nerve is cut

Answer 31

whole left eye vision is gone

Question 32

what happens when the right optic nerve is cut

Answer 32

whole right eye vision gone

Question 33

what happens when the optic chiasm is cut

Answer 33

middle view is gone (nasal hemiretina)

Question 34

what happens when the right optic tract is cut

Answer 34

left of middle and left temporal is gone

Question 35

what happens when the left optic tract is cut

Answer 35

right of middle and right temporal is gone

Question 36

what is binocular disparity

Answer 36

difference in image location by the left and right sides

Question 37

what sees close by things

Answer 37

temporal hemiretinas

Question 38

what sees far things

Answer 38

nasel hemiretinas

Question 39

what neuron sees just outside and inside the primary visual cortex (V1)

Answer 39

- retinal ganglion (tiny spots of light) - LGN (lateral geniculate nucleus): tiny spot of light ENTER VISION CORTEX - Layer C (tiny spot of light) - simple: lines and edges in particular orientation - complex lines/edges in a particular orientation any where in receptive field and moving bars of light

Question 40

receptive fields get more ______ as you go downstream

Answer 40

bigger and complex

Question 41

what is the optic flow

Answer 41

once processed in V1 it can go MT (middle temporal) then it goes to the medial superior temporal (MST)

Question 42

what does MT n MST detect

Answer 42

speed of motion and process object and self motion

Question 43

what is translational flow

Answer 43

integration info for eye to eye

Question 44

what is rotational flow

Answer 44

motion due to eye movement

Question 45

2 factors that generate optic flow

Answer 45

speed and direction of eye movement disttance between eye and points of focus

Question 46

what does optic flow give you

Answer 46

stability self velocity and direction object movement time to contact

Question 47

what is time to contact

Answer 47

for intercepting and avoiding things

Question 48

what is used to calculate time to contact

Answer 48

- optic flow - binocular disparity - oculomotor vergence feedback

Question 49

what part of vision deal with perception

Answer 49

ventral system (primary corex to temporal lobe)

Question 50

what part of vision deals with action

Answer 50

dorsal (primary vision to parital)

Question 51

evidence for perception stream

Answer 51

same different discrimination task (ventral) - look at something and see f they are the same

Question 52

evidence for action stream

Answer 52

object manipulation (dorsal) - hold object at stable point