Physiological measures of presence in stressful virtual environments

ACM Transactions on Graphics (2002), pp. 645-652, doi: 10.1145/566654.566630
Experiments
Tasks
Findings

Do multiple exposures to a stressful virtual environment environment reduce presence?

Variables

Independent Variables
System Info

Displays
Input Hardware
None
Software
None

Physiological measuring system (for heart rate, skin conductance, heart rate)

Participant Info

Participants had not experienced VR more than 3 times and were healthy. Average age was 24.4.

Total # Age Range Gender Balance
10 -

Users first practiced moving around and picking up objects in a training room. Users then picked up an object and carried it through a doorway to place it into the next room. In the next room, there was a hole in the floor with a virtual 20 foot drop with another room shown below. There was a narrow walkway around the hole. Users carried the object to the far side of the pit room and put it down.

Interaction and Environment

Interface

Users moved about freely and were tracked through their HMD.

The environment consisted of two rooms, one where the user started, with a few pieces of furniture and objects to pick up. A doorway, initially closed, leads to a room with a narrow walkway around the edge but which is otherwise a hole looking down to another furnished room 20 feet below.

Dimensionality Scale Density Visual Realism
3D Small Medium Medium
Metrics

  • presence - 13-question questionnaire; changes in skin conductance; changes in skin temperature
  1. There was a significant inverse effect of number of exposures on presence for a travel - search task.

    Multiple exposures reduced presence, especially the second such exposure, as measured by the questionnaire and by each of the physiological measures. Physiological measures were found (through all three experiments) to correlate with presence as measured

    Specificity: Somewhat general

Does the addition of passive haptics in stressful virtual environments increase presence?

Variables

    Haptic Fidelity
  • haptics (on/off) - passive haptics through a ledge around the hole in the pit room, or none (i.e. a flat floor).
System Info

Displays
Input Hardware
None
Software
None

Physiological measuring system (for heart rate, skin conductance, heart rate)

Participant Info

Participants had not experienced VR more than 3 times and were healthy. The average age was 21.4.

Total # Age Range Gender Balance
52 -

Users first practiced moving around and picking up objects in a training room. Users then picked up an object and carried it through a doorway to place it into the next room. In the next room, there was a hole with a virtual 20 foot drop with another room shown below. There was a narrow walkway around the hole. In the haptics condition, this walkway was raised 1.5 inches so that there was a drop where the hole was located. Users also wor thin sock-like slippers to better feel the ledge around the hole. Users were instructed to stand with their toes over the edge for ten seconds before moving to the other side of the room to place their object down.

Interaction and Environment

Interface

Users moved about freely and were tracked through their HMD.

The environment consisted of two rooms, one where the user started, with a few pieces of furniture and objects to pick up. A doorway, initially closed, leads to a room with a narrow walkway around the edge but which is otherwise a hole looking down to another furnished room 20 feet below.

Dimensionality Scale Density Visual Realism
3D Small Medium Medium
Metrics

  • presence - 13-question questionnaire; changes in skin conductance; changes in skin temperature
  • heart rate - heart rate monitor
  1. There was a significant direct effect of haptics (on/off) on presence for a travel - search task.

    Passive haptics increased presence as measured by the questionnaire and by each of the physiological measures. Physiological measures were found (through all three experiments) to correlate with presence as measured with the questionnaire, with heart rate

    Specificity: Somewhat general

Does frame rate affect presence in stressful virtual environments?

Variables

    Visual Fidelity
  • frame rate - 10, 15, 20, 30 frames-per-second
System Info

Displays
Input Hardware
None
Software
None

Physiological measuring system (for heart rate, skin conductance, heart rate)

Participant Info

Participants had not experienced VR more than 3 times and were healthy. The average age was 22.3.

Total # Age Range Gender Balance
33 -

Users first practiced moving around and picking up and dropping objects in a training room. Users then picked up an object and carried it through a doorway to place it into the next room. In the next room, there was a hole with a virtual 20 foot drop with another room shown below. There was a narrow walkway around the hole. Users dropped the object onto a red X shown at the bottom of the pit, then plucked from the air two other colored blocks and dropped them onto matching colored Xs in the pit.

Interaction and Environment

Interface

Users moved about freely and were tracked through their HMD.

The environment consisted of two rooms, one where the user started, with a few pieces of furniture and objects to pick up. A doorway, initially closed, leads to a room with a narrow walkway around the edge but which is otherwise a hole looking down to another furnished room 20 feet below. The bottom of the pit had three colored Xs marked on the ground.

Dimensionality Scale Density Visual Realism
3D Small Medium Medium
Metrics

  • presence - 13-question questionnaire; changes in skin conductance; changes in skin temperature
  • heart rate - heart rate monitor
  1. There was a significant direct effect of frame rate on presence for a travel - search task.

    Presence increased for increasing frame rate except that 10 FPS rated higher than 15 (but still less than 20 and 30) by all measures except for changes in skin conductance. According to the authors, the anomalous result at 10 FPS is most likely due to dis

    Specificity: Somewhat general