Health and Safety Implications of Virtual Environments

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Health and Safety Implications of Virtual
Environments

• Christina Abbott

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Articles

• The nauseogenicity of two methods of navigating
  within a virtual environment, (Howarth and Finch)
• Measurement of postural stability before and
  after immersion in a virtual environment, (Cobb)
• Motion sickness and proprioceptive aftereffects
  following virtual environment exposure, (Stanney,
  et al)

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Vestibular System

• A/K/A Balance System
• Dominant input about movement and orientation
  (wikipedia)

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Terms

• Proprioception
• Sense of the relative position of body parts.
  (wikipedia)
• Sensory Conflict Theory
• Conflicts between visual and vestibular inputs.
• Postural Stability
• Ability to maintain balance and postural control.
• Equilibrium System
• Input Visual, somotosensory, and vestibular
• Output body sway

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Motion Sickness, a/k/a/

• Cybersickness
• Virtual Simulation Sickness
• Extension of sickness experienced with
  flight/driving simulators, with is an extension
  of motion sickness (Howarth Costello)
• MMS (motion maladaption syndrome)
• Indication of intact vestibular function.
  (Howarth Finch)

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Causes of Motion Sickness

• Nueral Mismatch (1800s) - (Irwin) (James)
  (Pollack)
• Ecological Theory - (Stoffregen Riccio)

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Measurement of Motion Sickness

• Subjective and Objective Measures
• Nausea and vomiting
• Oculomotor disturbances
• Disorientation

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Analysis Howarth and Finch

• Researchers looked at nauseocenicity during
  immersion with head stabilized and free-moving.

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Possible Confounds Howarth and Finch

• Used subjective measures
• Participants slightly more susceptible to MMS.
• Could have correlated SSQ with measurable MMS
  symptoms.

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Results Howarth and Finch

• Head StabilizedHand Moving, increase in nasuea
• Head Moving-Hand Moving, significantly larger
  increase in nausea

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Interesting Points Stanney, et al

• Do VE users must physiologically adapt to VE?
• Joystick initially jerky
• Then rescale and adapt
• If adaptation occurs, then how can we assist with
  adapting back to real world?

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Analysis Stanney, et al

• Cites Kennedy, et al
• Flight simulators 60-70 pilots susceptible
• VE 90-95 susceptible.
• How are these two simulators different?
• Why so high for Virtual Environments?

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Results Stanney, et al

• Participants 30-minutes post-exposure SSQ was
  higher than pre-exposure.
• 30-minute post-exposure than 30-minutes post.

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Results - Stanney, et al

• Eyes-open Test scores - no change from baseline
• Eyes-closed test scores changes when compared
  with pre-tests
• After immersion felt limb pointing was higher and
  to the left with eyes closed.
• Females reported sickness scores at 35.5, while
  males reported 10.43

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Analysis Cobb

• Concerned with postural stability measurement
  tools.
• Static Postures
• Dynamic Tests
• Sway Posturography Measurement

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Method - Cobb

• Two Static Postures
• Tandem Romberg
• Normal stance
• Dynamic Tests
• WOFEC, WOLEC, WASP
• SSQ

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Results Cobb

• Dynamic Tests No significance
• Posturographic Technique Found mild postural
  instability.

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Why Low Significance Cobb

• VE had no effect
• Learning effect and Insensitivity of Tests
• Low reliability of tandem romberg
• Low stimulus.

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Follow Up

• MMS symptoms linger long after immersion.
• Sickness Questionnaire (SSQ) scores are higher 30
  minutes after immersion than before.
• What are the safety implications of this? For
  military, civilians, adults, children, seniors?