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Human Factors in VR Electrical and Computer Engineering Dept.

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Presentation on theme: "Human Factors in VR Electrical and Computer Engineering Dept."— Presentation transcript:

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2 Human Factors in VR Electrical and Computer Engineering Dept.

3 System architecture User(programmer, trainee, etc.)

4 Human factors in VR Human HumanPerformance Efficiency Efficiency Health Health and and Safety Safety Societal Societal Implications Implications (Stanney et al., 1998)

5 Human factors in VR Will the user get sick in VR? (Stanney et al., 1998) Which tasks are most suitable for users in VR? for users in VR? Which user characteristics will influence VR performance? Will there be negative societal impact from users misuse of the technology? the technology? What kind of designs will enhance users performance in VR? in VR? How much feedback from VR can the user process? Will the user perceive system limitations? How should VR technology be improved to better meet the users needs? ?

6 Human factors vocabulary HF study – series of experiments in very rigorous conditions aimed at the user (can be controlled or case study); Experimental protocol – establishes a structured sequence of experiments that all participants need to perform; Trial – a single instance of the experiment; Session - a sequence of repeated trials; Rest period – time between sessions; Experimental database – files that store experimental data; Institutional Review Board (IRB) – watchdog office regulating HF experiments Principal Investigator (PI) – person conducting the HF study. Needs to be certified by the IRB

7 H. F. vocabulary - continued H. F. vocabulary - continued Subject - a participant in a HF study (male or female, age, volunteer or paid, right handed or left handed, normal or disabled, etc); Experimental group – subjects on which the experiments are done; Control group – a number of subjects used for comparison with the experimental group; Controlled study – a study that uses both an experimental and control group Case study (also called pilot study) – smaller study with no control group. Feasibility Study – look at technology acceptance and effect Consent form – needs to be signed by all participants into the study; Baseline test – measurement of subjects abilities before trial;

8 Human factors in VR Human HumanPerformance Efficiency Efficiency Health Health and and Safety Safety Societal Societal Implications Implications (Stanney et al., 1998)

9 The stages of human factors The stages of human factors studies studies Determinefocus Recruitsubjects Conduct study Develop experim. protocol Analyze data

10 The stages of human factors The stages of human factors studies studies Determine focus Recruit subjects Conduct study Develop experim. protocol Analyze data

11 Human factors focus What is the problem? (ex. People get headaches) Determines the hypothesis (ex. Faster graphics is better); Establishes type of study (usability, sociological, etc.); Objective evaluation, subjective evaluation or both? …

12 The stages of human factors The stages of human factors studies studies Determine focus Recruit subjects Conduct study Developexperimentalprotocol Analyze data

13 Experimental protocol What tasks are done during one trial? How many trials are repeated per session? How many sessions per day, and how many days for the study? How many subjects in experimental and control group? What pre and post-trial measurements are done? What variables are stored in the database? What questions on the subjective evaluation form?

14 The stages of human factors The stages of human factors studies studies Determine focus Recruit subjects Conduct study Develop experim. protocol Analyze data

15 Subject recruitment Sufficient number of subjects need to be enlisted in the study to have statistical significance; Place advertisements, send targeted s, web posting, go to support/focus groups, friends, etc.; Subjects are screened for unsuitability to study; Subjects sign consent form; Subjects are assigned a code to protect their identity; Subjects sign release for use of data in research, Subjects may get exposure to technology;

16 The stages of human factors The stages of human factors studies studies Determine focus Recruit subjects Conduct study Develop experim. protocol Analyze data

17 The stages of human factors The stages of human factors studies studies Determine focus Recruit subjects Conduct study Develop experim. protocol Analyze data

18 Data Collection VR can sample much larger quantity of data and at higher temporal density than classical paper-and-pencil methods; Data recorded online can be played back during task debriefing and researchers do not have to be co-located with the subjects (remote measurements); Measurements need to be sensitive (to distinguish between novice and expert users), reliable (repeatable and consistent) and valid (truthful); Latencies and sensor noise adversely affect these requirements.

19 Data Analysis Experiments store different variables, depending on the type of test: task completion time – time needed to finish the task (can use system time, sequence of actions, or stopwatch); task error rate – number or percentage of errors done during a trial; task learning – a decrease in error rate, or completion time over a series of trials; Analysis of Variation (ANOVA) – statistical package used to analyze data and determine if statistical difference exists between trials or conditions.

20 Data analysis - continued Average Standard deviation Standard deviation Error rates Error rates Trial number Trial number 123 Task learning Task learning Learning results in less errors and more uniform performance among subjects

21 Data analysis - continued Effect of prior knowledge on task learning Error rates Error rates Trial number Trial number 123 Group A Group B (very easy task) Group C (very difficult task)

22 Data analysis - continued Error rates or Error rates or completion time Feedback modality Feedback modality NHH-A Stereoscopic Group High fps, small variability in fps Monoscopic Group, small fps, high fps variability

23 Data analysis - continued Task learning time and error rates are applicable to VR in general; Performance measures which are modality specific – for example for force feedback - Average contact force – the forcefulness of the interaction with a virtual object Average force =________ N where N is the number of data samples and f i is the magnitude of the i-th force N i=1 f i i=1 f i

24 Another modality-specific performance measure is the cumulative contact force. Higher cumulative forces/torques indicate higher subjects muscle exertion This can lead to muscle fatigue of haptic interface premature wear. There are also task-specific performance measures, such as those associated with cognitive tasks (heart rate, muscle tone, skin conduction, breathing rate, etc.) Cumulative force = Where t is the sampling interval Data analysis - continued N i=1 f i t i=1 f i X t

25 A subclass of human factors research to determine the ease (or difficulty) of use of a given product; It differs from general-purpose VR human factors studies which are more theoretical in nature; Usability studies are product-oriented and part of the product development cycle. There are no clear standards, because this is an area of active research. Usability Engineering Usability Engineering

26 The methodology consists of four stages: Usability Engineering Usability Engineering User task analysis FormativeUsabilityevaluation Summativeevaluation Expert guidelines- basedevaluation

27 Sea Dragon military command and control application Sea Dragon military command and control application

28 The first stage – define the task and list users actions and system resources needed to do it; Identifies the interrelationships (dependencies and order sequences) and user information flow during the task; Poor task analysis is a frequent cause of bad product design. For Dragon, the task is 3-D navigation and object (symbol) selection and manipulation. it differs from classical 2-D maps and symbols. Usability Engineering Usability Engineering User task analysis FormativeUsabilityevaluation Summativeevaluation Expert guidelines- basedevaluation

29 The second stage (sometimes called heuristic evaluation) aims at identifying potential usability problems early in the design cycle. A pencil-and-paper comparison of users actions done by experts, first alone, and then as a group (to determine consensus); For Dragon, ease of navigation was identified as a critical issue; experts identified problems with the system responsiveness, when using a flight stick (wand with buttons) and performing exocentric navigation (the user was outside of the environment, looking in). Usability Engineering Usability Engineering User task analysis FormativeUsabilityevaluation Summativeevaluation Expert guidelines- basedevaluation

30 The third stage is an iterative process where representative users are asked to perform the task; During task performance variour variables are measured, such as task completion time and error rates. These are used to do product re- design and the process is repeated; Dragon formative evaluation had two stages. During the first stage the best interface was selected between three candidates (PinchGlove, voice recognition and wand). Voice recognition was ineffective, and PinchGlove produced time delays when transferring to another user. Thus wand was selected. Usability UsabilityEngineering User task analysis FormativeUsabilityevaluation Summativeevaluation Expert guidelines- basedevaluation

31 The second stage of Dragon formative evaluation used a large number of subjects that had to navigate, while errors were recorded. A large effort was made in mapping the wand button to functions. Pan and zoom were mapped to the wand trigger, pitch and heading to the left button, while exocentric rotate and zoom were mapped to the right button Usability UsabilityEngineering User task analysis FormativeUsabilityevaluation Summativeevaluation Expert guidelines- basedevaluation

32 The last stage is Summative evaluation which is done at the end of product development cycle. It is done to statistically compare the new product with other (competing) products to determine which is better. The selection among several candidates is done based on field trials and expert reviews. The summative evaluation of Dragon involved the study of four parameters: navigation metaphor (egocentric or exocentric), gesture mapping (rate or position control of camera), display device (workbench, desktop, wall or CAVE) and graphics mode (stereo or mono) Usability Engineering Usability Engineering User task analysis FormativeUsabilityevaluation Summativeevaluation Expert guidelines- basedevaluation

33 Usability Engineering Usability Engineering The summative evaluation of Dragon involved thirty two subjects divided in groups of four. Each group was assigned a different combination of conditions.

34 Usability Engineering Usability Engineering Results showed that users: o performed fastest on a desktop monitor; o were slowest on the workbench. o Egocentric navigation was fastest in monoscopic graphics o Exocentric navigation was fastest in stereo graphics. o Rate control was fastest in monoscopic graphics; o Position was fastest for stereo graphics.

35 Testbed Evaluation of Universal VR Tasks Testbed Evaluation of Universal VR Tasks Testbeds are a way to deal with evaluation complexities. They are composed of a small number of universal tasks such as travel in a virtual environment, object selection and object manipulation; Provide a structured way to model subject performance, although the evaluation is more expensive to do. Testbeds make possible to predict subjects performance in applications that include the tasks, sub-tasks and interaction techniques they use.

36 Testbed Evaluation of Universal VR Tasks - continued Testbed Evaluation of Universal VR Tasks - continued Testbed evaluation of navigation tasks: obstacles (trees and fences) and targets (flags) can be randomly placed. There were 38 subjects divided in 7 groups, each using a different Navigation technique (steering based, manipulation-based and target specification techniques)

37 Testbed Evaluation of Universal VR Tasks - continued Testbed Evaluation of Universal VR Tasks - continued Steering-based: Pointing, gaze tracking or torso tracking; Manipulation-based: HOMER or Go-Go; In go-go the subject stretches his hand into the virtual world, grasps an object and then pulls the virtual camera forward; Target-specification: ray casting or dragging. Fastest – gaze-directed (but produced eye strain and nausea)

38 Testbed Evaluation of Universal VR Tasks - continued Testbed Evaluation of Universal VR Tasks - continued Testbeds used for object selection and placement tasks; Subjects had to select a highlighted cube and place it in a target area (between the two gray cubes);

39 Testbed Evaluation of Universal VR Tasks - continued Testbed Evaluation of Universal VR Tasks - continued There were 48 subjects divided among 9 groups. Object selection was done either by ray casting or occlusion. Scene was seen on HMD; For each subject the distance to the object, the DOF used for box Manipulation (2 or 6) or ratio of object/target size (1.5x, 3.75x) varied. Distant objects were harder to select, Go-Go was slowest mode.

40 System responsiveness inverse proportional to the time between user input and the simulation response to that input. HF studies done at Rutgers in early 90s to determine influence of refresh rate (fps) and graphics mode (mono/stereo) on tracking task performance in VR; Subjects were 48 male and 48 female (volunteer undergrad students), right handed. Task was the capture of a bouncing ball in the smallest amount of time; Subjects were divided in sub-groups, each having a different refresh rate, and graphics mode; Each subject performed 12 trials separated by 15 seconds rest periods; Ball appeared with random velocity direction and maintained a speed of 25 cm/sec Influence of System Responsiveness on User Performance Influence of System Responsiveness on User Performance

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42 Ball capturing time was influence sharply by the graphics refresh rate, especially when the rate fell below 14 fps; The standard deviation grew with the decrease in fps, indicating less uniformity among the subjects in the experimental groups; Stereo made a big difference for low refresh rates, where task completion time was approximately 50% of the time taken to complete the task under monoscopic graphics; the subjects had different strategies for grasping the ball At low refresh rates, where the ball motion appeared saccadic, they grasped in a corner, keeping their arm stationary, At high refresh rates they moved theirs hand in a ballistic way to capture it. Influence of System Responsiveness on User Performance Influence of System Responsiveness on User Performance

43 Frames per second (fps) Frames per second (fps) Mean completion time (sec) Mean completion time (sec) Mono graphics Mono graphics Stereo graphics Stereo graphics Effect of frame rate and graphics mode on task completion time (Richard et al., 1995) Influence of System Responsiveness on User Performance Influence of System Responsiveness on User Performance

44 The frame refresh rate had a significan influence on the way subjects learned; The group with highest task learning was that corresponding to monoscopic graphics displayed at 1 fps. Influence of System Responsiveness on User Learning Influence of System Responsiveness on User Learning completion time (sec) completion time (sec) Trial number Trial number Mono graphics Mono graphics

45 The least learning was for the groups with high refresh rates (14 fps and 28 fps). Their curves were almost flat; Stereo had a beneficial effect on learning (subjects were more familiar to the task – it was presented more realistically to them). Influence of System Responsiveness on User Learning Influence of System Responsiveness on User Learning completion time (sec) completion time (sec) Stereo graphics Stereo graphics Trial number Trial number

46 Watson performed a test to determine the influence of system responsiveness and its variability (expresses as Standard Deviation of System Responsiveness) on object placement tasks. The task was to capture an object and place it on a pedestal, while receiving monoscopic graphics feedback; System responsiveness was altered by changing the frame refresh rates to 17fps, 25fps and 33 fps. For each frame rate, the SDSR was changed from 5.6%, 22.2% and 44.4%; Influence of System Responsiveness on Object Placement tasks Influence of System Responsiveness on Object Placement tasks

47 Results showed that subject performance (expressed as placement time and accuracy) was effected by both SR and SDSR. The variability in system responsiveness had the largest influence on placement tasks done at low refresh rates. The worst was placement done at 17 fps, with 44.4% SDSR. When done at 33 fps and 5.6% SDSR accuracy improved 90%. Influence of System Responsiveness on Object Placement tasks Influence of System Responsiveness on Object Placement tasks

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49 HF studies done at University of Birmingham in late 90s to determine influence of force feedback mode on task completion time in VR; Task was the manipulation of disks to construct the Tower of Hanoi. Four conditions – non-immersive VR with 2-D mouse, immersive (HMD) with 3-D mouse, immersive with instrumented objects, and real objects; Use of instrumented objects (disks with a tracker attached) to provide force feedback – augmented VR Subjects were four male with six-months experience in VR each; Each subject performed 10 trials for each condition, conditions were randomized. Influence of Feedback Multi-modality Influence of Feedback Multi-modality

50 Tower of Hanoi task Problem – Problem – Stack three rings on another pole; Larger ring never on top of smaller one Influence of Feedback Multi-modality Influence of Feedback Multi-modality

51 3-D manipulation task – Tower of Hanoi 3-D manipulation task – Tower of Hanoi (Boud et al., 2000) experimental setup (IO condition) experimental setup (IO condition) Virtual scene during experiments Virtual scene during experiments Influence of Feedback Multi-modality Influence of Feedback Multi-modality

52 (Boud et al., 2000) Task completion time (sec) experimental condition experimental condition Tower of Hanoi performance Influence of Feedback Multi-modality Influence of Feedback Multi-modality

53 Influence of sensorial redundancy and substitution Influence of sensorial redundancy and substitution Definition Sensorial substitution (or transposition) occurs whenever information that is usually in one sensorial domain is presented to the brain through another sensory system. Sensorial redundancy involves the use of several (at least two) sensorial domains to present the same information to the subject.

54 HF studies done at Rutgers in mid 90s to determine influence of force feedback mode on task performance in VR; Task was the manipulation a deformable virtual ball on a prescribed path, in shortest time; Ball needed to be deformed 10% of radius or less; Subjects were male and female (volunteer undergrad students), right handed, and none had seen the system before; Subjects were divided in sub-groups, each having a different force feedback modality and graphics mode; Frame rate was maintained at 28 fps; Each subject performed 12 trials separated by 15 seconds rest periods; Influence of sensorial redundancy and substitution Influence of sensorial redundancy and substitution

55 3-D capturing and manipulation task setup 3-D capturing and manipulation task setup Influence of sensorial redundancy and substitution Influence of sensorial redundancy and substitution

56 Sensorial substitution Sensorial substitution Influence of sensorial redundancy and substitution Influence of sensorial redundancy and substitution

57 3-D manipulation task 3-D manipulation task Mean object deformation (%) Mean object deformation (%) Force Feedback Modality Force Feedback Modality RMII RMII RMI RMI Effect of interface dynamic range on task performance (Fabiani et al., 1996) Influence of sensorial redundancy and substitution Influence of sensorial redundancy and substitution

58 This happens during cross-modal enhancement – when weak haptic feedback is supplemented by another modality. Example – Bioccas study found that 30% of subjects reported feeling the weight and inertia of virtual objects when interacting with PinchGloves Sensorial Illusion Sensorial Illusion

59 Another form of sensorial illusion is provision of haptic texture feedback through vision By manipulating the gain in mouse arrow movement in response to user real movement it is possible to simulate bumps and valleys in the object surface Sensorial Illusion Sensorial Illusion Supplemental video Download and experience these textures from

60 Another form of sensorial illusion in sensorial conflict in which information from one sensorial channel contradicts that received by another sensorial channel. An extreme case of sensorial conflict is simulation sickness which will be discussed later. French researchers studied the boundary of illusion between conflicting visual and haptic feedback. Sensorial Conflict Sensorial Conflict VC 7.1

61 Human factors in VR Human HumanPerformance Efficiency Efficiency Societal Societal Implications Implications (Stanney et al., 1998) Health Health and and Safety Safety

62 The effects VR simulations have on users can be classified as direct and indirect; Effects of VR Simulations on users Effects of VR Simulations on users Definitions Direct effects involve energy transfer at the tissue level and are potentially hazardous; Indirect effects are neurological, psychological, sociological,or cybersickness and affect the user at a higher functional level.

63 Affect mainly the users visual system, but also the auditory, skin and musculoskeletal systems; Effects on the skin and muscles are due to haptic feedback at too high a level. The intensity of Wii game playing can lead to injury. Statistics posted on Direct Effects of VR Simulations on Users Direct Effects of VR Simulations on Users

64 Effects on the visual system occur when the user is subjected to high-intensity lights directed at his eyes (like Lasers used in retinal displays (if they malfunction), or IR LEDs as part of eye tracking systems; An absence state can be induced in a user subjected to pulsing lights at low frequency (1-10 Hz); Bright lights coupled with loud pulsing sounds can induce migraines (20% of women and 10% of men are prone to migraines. Direct effects on the auditory system are due to simulation noise that has too high a level (115 dB after more than 15 minutes); Direct Effects of VR Simulations on Users Direct Effects of VR Simulations on Users

65 User safety concerns relate primarily to cyber sickness, but also to body harm when haptic feedback is provided; Cyber sickness is a form of motion sickness present when users interact with virtual environments; Cyber sickness has three forms: Nausea and (in severe cases) vomiting; Eye strain (Oculomotor disturbances); Disorientation, postural instability (ataxia) and vertigo. Flight simulators have an incidence of up to 60% of users experiencing simulation sickness (military pilots – elite group); Studies suggest regular VR users are affected more (up to 95%) (Stanney and Hash, 1998) Cyber sickness Cyber sickness

66 Since many users are affected, it is important to study cyber sickness, in order to reduce its effects, and allow wide-spread use of VR; Few studies exist. Based on these the following model was developed: Cyber sickness Model Cyber sickness Model PriorExperience Simulationsickness HumanBody NeuralConflict VirtualEnvironment Adaptation Aftereffects

67 The Cyber sickness model The Cyber sickness model PriorExperience Simulationsickness HumanBody NeuralConflict VirtualEnvironment Adaptation After-effects

68 When VR technology has problems, it can induce simulation sickness. Example: - Tracker errors that induce a miss-match between user motion and avatar motion in VR; - System lag that produces large time delays between user motion and simulation (graphics) response. Lag is in turn influenced by tracking sampling speed, computer power, communication speed, and software optimization. - HMD image resolution and field of view. Poor resolution and small FOV are not acceptable. Large FOVs can also be problematic. System characteristics influencing cyber sickness System characteristics influencing cyber sickness

69 The user characteristics can play an important role in cyber sickness: - Age that induce a miss-match between user motion and avatar motion in VR; - Health status. Sick users, including those that take medication or drugs are more prone to cyber sickness. - Pregnancy. Female users who are pregnant are more prone to simulation sickness. - Susceptibility to motion sickness. Some people are more prone to motion sickness than others. Pilots are screened for such. Influence of users characteristics on cyber sickness Influence of users characteristics on cyber sickness

70 The Cyber sickness model The Cyber sickness model PriorExperience Simulationsickness HumanBody NeuralConflict VirtualEnvironment Adaptation After-effects Degree of Degree ofInteractivity

71 HF studies done at University of Central Florida (Stanney and Hash, 1998) to determine influence of user degree of control on cyber sickness in VR; Task was 3-D navigation in a maze (shown below): Influence of users degree of interactivity on cyber sickness Influence of users degree of interactivity on cyber sickness 3-D navigation task (Stanney and Hash, 1988)

72 There were three control conditions: Passive control – users were taken on a ride on a preprogrammed path, and had no input to the simulation; Active control – users navigated using a joystick with 6 DOF; Combined active-passive control – users navigated using the same joystick, but with some degrees of freedom disabled, based on task- specific motions (doors, windows, elevators); There were eight subjects in each experimental group (24 total, both male and female); They each performed the task for 30 minutes; The virtual environment was displayed on a PC in stereo, so subjects wore stereo glasses. Results showed that active-passive control reduced significantly cyber sickness effects. Passive control did worse. 3-D navigation task (Stanney and Hash, 1988) Influence of users degree of interactivity on cyber sickness Influence of users degree of interactivity on cyber sickness

73 Nausea NauseaOculomotordistortionDisorientation Total severity SSQ Score SSQ Score Active-passive control is better than active control, because unnecessary motions are eliminated, thus reducing the amount of neural conflicts. Both reduce adaptation time. Simulation sickness was self-reported by subjects using a Simulation Sickness Questionnaire (SSQ) 3-D navigation statistics (Stanney and Hash, 1988) Passive Control Passive Control Active Control Active Control Active-Passive Control Influence of users degree of interactivity on cyber sickness Influence of users degree of interactivity on cyber sickness

74 The Cyber sickness model The Cyber sickness model PriorExperience Simulationsickness HumanBody NeuralConflict VirtualEnvironment Adaptation After-effects

75 Occurs when simulation and body sensorial feedbacks conflict; The conflict (sensorial rearrangements) can be of three types: Type I: two simultaneous conflicting signals (A and B) – example Information from a moving platform does not coincide with the motion of waves seen on an HMD. Type II: Signal A is present and B is not – example looking at a roller coaster simulation, without a motion platform; Type III: Signal B is present and signal A is not – flight simulation in fog (instrumented flight). Motion platform moves, but visual feedback is unchanged. Since more information from the simulation results in more conflict, it is logical that neural conflict induced cyber sickness grows with the duration of immersion in the VE. Neural Conflict Neural Conflict

76 HF studies done at University of Central Florida (Kennedy et al., 2000) to determine influence of simulation duration on cyber sickness; Task was flying a helicopter, and subjects were military pilots; The data was divided according to duration in: Simulation session of 1 hour or less; 1 to 2 hours; 2 to 3 hours; Simulation session of over three hours It showed that there is a linear relationship between duration of simulation and the degree of simulation sickness; Thus the duration of initial exposure should be limited, to minimize discomfort; Influence of exposure duration on cyber sickness Influence of exposure duration on cyber sickness

77 Influence of simulation duration on cyber sickness Influence of simulation duration on cyber sickness (Kennedy et al., 2000) Flight Session Duration (in hours) Flight Session Duration (in hours) Average Total Sickness Score Average Total Sickness Score

78 The Cyber sickness model The Cyber sickness model PriorExperience Simulationsickness HumanBody NeuralConflict VirtualEnvironment Adaptation After-effects

79 HF studies done at University of Central Florida (Kennedy et al., 2000) to determine influence of user adaptation on cyber sickness; Since prior neural images play such an important role in cyber sickness, can repeated exposure to VR desensitize the user? Study looked at military helicopter simulators, thus subjects were pilots, and task was prone to induce sickness (violent maneuvers). Influence of repeated exposure on cyber sickness Influence of repeated exposure on cyber sickness

80 The study used a Total Sickness Score with a 35% as zero-point. Thus for military pilots 35% incidence of simulator sickness is considered acceptable. For the general public it is not. Results showed a significant reduction in TSS after a few flights showing that the subject had adapted to the neural mismatch. While mismatches exist, there are considered as matches due to prior experience. Influence of repeated exposure on cyber sickness Influence of repeated exposure on cyber sickness

81 The study did not indicate how long the subsequent exposures should be, nor over what time interval they should take place. It is believed that no more than one week should separate simulation sessions. Influence of repeated exposure - results Influence of repeated exposure - results Cyber sickness scores vs. number of successive flights (Kennedy et al., 2000) Average Total Sickness Score Average Total Sickness Score Flight Number Flight Number

82 Adaptation Adaptation Definition Adaptation to sensory rearrangement is a semi-permanent change of perception and/or perceptual-motor coordination that serves to reduce or eliminate a registered discrepancy between, or within, sensory modalities, or the errors in behavior induced by this discrepancy. a) before VR exposure Hand-eye coordination adaptation [Groen and Werkhoven 1998]. b) initial mapping through artificial offset d) aftereffects c) adapted grasping

83 The Cyber sickness model The Cyber sickness model PriorExperience Simulationsickness HumanBody NeuralConflict VirtualEnvironment Adaptation Aftereffects

84 Induced through adaptation to neural conflicts. Occur after the simulation session ended and can last for hours or days; While adaptation is good, aftereffects may be bad. Forms of aftereffects are: Flashbacks; Sensation of self motion; Aftereffects Aftereffects

85 Headache and head spinning; Diminished (remapped) hand-eye coordination; Vestibular disturbances; These aftereffects lead Navy and Marines to institute grounding policies after simulator flights. Other bans may be necessary (example driving, biking, roof repair, operating machinery, etc.). Aftereffects Aftereffects

86 Meant to minimize the onset and severity of cybersickness. They are largely qualitative Guidelines for Proper VR Usage Guidelines for Proper VR Usage

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88 Human factors in VR Human HumanPerformance Efficiency Efficiency Health Health and and Safety Safety Societal Societal Implications Implications (Stanney et al., 1998)

89 Violence of VR games are a concern, as additive response could result. Violence may also induce desensitization to real-world violence. This may be another negative after-effect of VR. Another social impact may be increased individual isolation, through reduced societal direct interaction and involvement. Avatar-mediated interaction, while allowing sharing of virtual worlds may not be a substitute to direct human-human interaction. Social implications of VR Social implications of VR

90 Second Life Online Society People become members, then can build communities or islands, buy at virtual stores and play games. An online 3D virtual world imagined and created by its Residents Social implications of VR Social implications of VR

91 Second Life Online Society Second Life Online Society Create content SocializeEvents/Games

92 Synthetic and distance learning using VR may not adequately replace direct student-professor interaction. Reduction in education quality may result; Reduction in health-care quality may also be present – especially for mental health and at-home rehabilitation. However for seniors VR reduces the sense of isolation and Can be used in brain training. Social implications of VR Social implications of VR

93 Mental rehabilitation VR systems One form of game-based mental training is the Nintendo DS and Nintendo DS Lite One form of game-based mental training is the Nintendo DS and Nintendo DS Lite It allows seniors to have fun while playing mind-challenging games, using a stylus and voice input It allows seniors to have fun while playing mind-challenging games, using a stylus and voice input Brain Age 2 has100 activities designed to help work your brain and increase blood flow to the prefrontal cortex. Brain Age 2 has100 activities designed to help work your brain and increase blood flow to the prefrontal cortex.

94 Mental rehabilitation VR systems When starting a new game, you will take a series of tests that show how old your brain is (Brain Age). When starting a new game, you will take a series of tests that show how old your brain is (Brain Age). With daily training over weeks and months, you can improve your mental acuity and lower your Brain Age. With daily training over weeks and months, you can improve your mental acuity and lower your Brain Age. Can compete against others Can compete against others

95 Online Cognitive Rehabilitation Online Cognitive Rehabilitation The Lumosity Co. (lumosity.com) allows subscription ($10/month) to video games that train the attention, memory, cognitive control and processing speed with against-the-clock games. After 30 sessions subjects that played the games also improved in independent tests of memory.

96 The dangers of video games (general) EverQuest Excessive game play can be fatal. In Korea, where 30% of the population subscribes to online multiplayer games, one man died in 2005 after playing 50 hours (almost non-stop) StarCraft. 3 Chinese died in 2007 after playing more than 50 hours, and 2 died in EverQuest is a 3D online game played by more than 400,000 people; Games can lead to isolation, and suicide. Hudson Wooley, an epileptic who was playing 12-hours per day, eventually committed suicide.


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