Chapter 2

Question 1

transducer

Answer 1

device that converts energy from one form to another

Question 2

sensor

Answer 2

special transducer that converts the energy it receives into a signal for electrical circuit (analog or digital) - sense organ

Question 3

receptor

Answer 3

sensor has it that collects energy for conversion

Question 4

neural impulses

Answer 4

what sense organs covert energy into

Question 5

degrees of freedom of sense organ

Answer 5

the organ has configuration space responding to all ways it can be transformed or configured- 6 DOF

Question 6

position DOF

Answer 6

side to side, vertical and closer further

Question 7

rotated DOF

Answer 7

yaw pitch and roll (used as independent paramteres needed to specify how object is oriented

Question 8

virtual world generator

Answer 8

produces another world, human perceives virtual world through target sense organ using display, which emits energy that is designed to mimic type of stimulus that would appear without vr

Question 9

rendering

Answer 9

converting information from vwg into output for display

Question 10

world fixed versus user fixed

Answer 10

subwoofer versus headphones

Question 11

hardware components of vr

Answer 11

display (output), sensors (input), computers

Question 12

dipslays for vr

Answer 12

devices that each sitmulate sense organ

Question 13

sensors fro vr

Answer 13

devices that extract informtaion from the real world

Question 14

computers for vr

Answer 14

devices that process inputs and outputs sequentially

Question 15

display technologies for direct retinal stimulation

Answer 15

digital light processing, liquid crystal display, liquid crystal on silicon

Question 16

sensor - orientation is accomplished by

Answer 16

inertial measurement unit

Question 17

gyroscrop

Answer 17

measures own rate of rotation

Question 18

angular velocity

Answer 18

rate of rotation

Question 19

drift errro

Answer 19

error when measurements from gyroscope are itnegrated over time to estimate culuative change in orientation

Question 20

accelerometer and magnetometer

Answer 20

reduce drift error

Question 21

depth camer

Answer 21

work actively by projecting light into the scene and observing its reflection in the image done in infrared spectrum

Question 22

graphical processing units

Answer 22

optimized for quickly rendering graphics to a screen

Question 23

hardware componenets for oculus drift

Answer 23

smartphone screen as display, circuit board that contains imu, dsplay interface chip, usb driver chip, set of chips for drivign led on headset for tracking, programmable microcontroller, lenses, camera for tracking

Question 24

vr engine

Answer 24

similar to game engines

Question 25

software development kit

Answer 25

handles lowest level operations like device drivers, head tracking and display output

Question 26

texture mapping

Answer 26

camera images taken of a real object and mapped onto syntetic object in a virtual world

Question 27

matched zone

Answer 27

users motion are confined to a safe region

Question 28

locomotion

Answer 28

moving oneself in virtual world while motion is not matched in real world

Question 29

collision detection algoritm

Answer 29

determines wheterh two or more bodies are intersecting in the virtual world

Question 30

perceptual psychology in vr

Answer 30

how brain converts sensory stimulaion into perceived phenomena

Question 31

questions related to perceptual psychology

Answer 31

how far away object appears to be, how much video resolution needed to avoid seeing pixels, frames per second enough to perceive motion as continuous, users head appearing at proper height in virtual world, where is virtual sound coming from, why am i feeling nauseated, why is one epxerience more tirign than another, what is presence

Question 32

sense, stimulus and receptor

Answer 32

vision, electromagetic energy, photoreceptors
auditory, air pressure waves, machanoreceptors
touch, tissue distortion, mechanorecpetors and thermoreceptors
balance, gravity/acceleration, mechanoreceptors
taste/smell, chemical composition, chemoreceptors

Question 33

sensory system selectivity

Answer 33

each receptor is thought of as a sensor that targets a particular kind of stimulus

Question 34

when does perception happen

Answer 34

after sense organs convert the stimuli into nerve impulses

Question 35

what part of the brain handles perception

Answer 35

cerebral cortex

Question 36

topographic mapping

Answer 36

reveal spatial relationships among receptors are maintained and among distribution of neruons

Question 37

propioception

Answer 37

ability to sense relative positions of parts of our bodies and amount of msucular efforts being involved in movin them

Question 38

motor cortex

Answer 38

controls body motiion

Question 39

efference copies

Answer 39

signals the motor cortex sends to other parts of the brain to communication which motions were executed

Question 40

encoders

Answer 40

indicate how far they hav emoved - robots

Question 41

vection

Answer 41

illusion of self motion - bad sneosry conflict because vision reports to brain you are accelerating but balance sense reports you are motionless

Question 42

adaptation

Answer 42

perceived effect of stimuli changes over time

Question 43

perceptual training

Answer 43

can lead to adaptation

Question 44

training that an untrained eye would miss (examples)

Answer 44

large amoung of tracking latency interfering with perception of stationarity, left and right eye views swapped, object apepar to one ey but not hte other, one eye view has more latency, straight lnes are slightly curved du to uncorrected warping

Question 45

psychophyics

Answer 45

study of perceutla phenomena produced by physical stimuli

Question 46

stevens power law

Answer 46

characterizes the relationship between magnitude of physical stimulus and perceived magnitude (p = cm^x, where p is perceive magnitude,m is magnitude or intensity of timulus, x is actual magnitude related to perceived, c is constant)

Question 47

just noticable difference (JND)

Answer 47

amount that stimulus needs to be changed so subjects would perceive it to have changes in at least 50% of trials (webers law delta m // m so jnd divided by magntude equal to constant)