Chapter 7

Question 1

3 things physics of motion is used for

Answer 1

tracking head motion, by the virtual world generator for rendering virtual scenes, to understand vestibular function and perception

Question 2

velocity is what

Answer 2

a change in position over time

Question 3

what is acceleration

Answer 3

chagne in velocity over time

Question 4

relation of position to velocity to acceleration

Answer 4

derivatives and integrals of each other

Question 5

3d motion position defined by what

Answer 5

3 coordinates (xyz)

Question 6

3d motion velocity defined by what

Answer 6

3 coordinates (vx, vy, vz)

Question 7

3d motion can be represented by what

Answer 7

vector

Question 8

what does the length of 3d motion velocity equate to

Answer 8

3d speed

Question 9

angular velocity is what

Answer 9

omega (derivative of time)

Question 10

angular acceleration is what

Answer 10

alpha (?) (derivative of omega over time)

Question 11

3D angular motion can be represented by what

Answer 11

vector

Question 12

what does the direction of the vector representing 3D angular motion represent

Answer 12

axis of rotation

Question 13

what does the magnitude of the vector representing 3D angular motion represent

Answer 13

speed of rotation

Question 14

what are inertial measurement units int he head used for (3things)

Answer 14

control reflexive eye movements, balance and posture (reflexive and not), perception of self motion and position like spatial orientation and navigation

Question 15

vestibular organs have separate organs for what two things

Answer 15

rotation and translation

Question 16

vestibular organs transduce head what

Answer 16

acceleration

Question 17

semicircular canals response during vestibular transduction

Answer 17

decay for constant velocity stimulus (sensitivity to 1 deg/s)

Question 18

otolith response to vestibular trasnduction

Answer 18

respond to linear acceleration and gravity (sensitivity of 5 cm/s2

Question 19

each hair in the ear is sensitivite to waht

Answer 19

1D motion

Question 20

what are the three semicircular canals

Answer 20

horizontal, anterior, posterior

Question 21

how many degrees of freedom do the semicircular canals have

Answer 21

3 dof

Question 22

what are the 3 properties of the three canals

Answer 22

left and right canals are paired, respond oppositely, push and pull system

Question 23

how many planes are the otoliths comprised of

Answer 23

2 planes - sagittal (veritcal) and horizontal (transverse)

Question 24

how many degrees of freedom do the otoliths have

Answer 24

3 dof

Question 25

what is the response of semicircular canals to constant velocity

Answer 25

no response, fluid catches up to movement

Question 26

einsteins equivalence principle (3 properites

Answer 26

gravity and inertial forces due to acceleration are equivalent, linear accelerometer can only measure their sum, gravito interial force is the sum of forces acting on a body

Question 27

what is the somatogravic illusion

Answer 27

when you accelerate forward while sitting upright (graviaty, interial force, gravitor inertial force), you perceive not to accelerate and to experience a backward tilt (gravity and gravitointerial)

Question 28

otoliths contribute to what

Answer 28

angular motion sensing (if rotate outside horizontal plane, can tell about rotation)

Question 29

canals contribute to what

Answer 29

linear motion sensing (info about how it is tilted - estimation and subtraction of gravity)

Question 30

canal otolith fusion

Answer 30

otolith contributes to angular motion sensing and canals contibue to linear motion sensing

Question 31

vestibuloocular reflex consists of what

Answer 31

3 neurons, 2 synapses, 10 ms

Question 32

vestibulocollic reflex

Answer 32

when you move an owl around and they dont move their head along with their body

Question 33

vestibulo spinal reflexes

Answer 33

postural reflexes - project to anti gravity muscles in the legs

Question 34

vestibular perception of rotation (angular) or translation (linear) thresholds

Answer 34

did you rotate left or right, did you move left or right

Question 35

self motion in the real world stimulates both

Answer 35

visual and vestibular systems

Question 36

in vr, there is visual self motion (optic flow) int he absense of what

Answer 36

vesibular stimulation

Question 37

vection is the sense of self motion induced by wht

Answer 37

vision - lead to simulator sickness

Question 38

3 causes of vestibular visual conflict

Answer 38

vehicle travle, visual displays, vestibular dysfunction

Question 39

3 consequencs of visual vestibular conflict

Answer 39

dizziness and vertigo, nausea, other physiological responses

Question 40

what two hypotheses were formed to answer why conflict leads to sickness

Answer 40

poison and antomical coincidence

Question 41

ways to avoid simulator sickenss

Answer 41

reduce visual optic flow (fov reduction), artifical vestibular stimulation (galvanic vestibular stimulation), simtulate motions below vestibular threshold (constant os lowly changing velcity)