Locomotion Mode Affects the Updating of Objects Encountered During Travel: The Contribution of Vestibular and Proprioceptive Inputs to Path Integration

Presence: Teleoperators and Virtual Environments (1998), pp. 168-178, doi: 10.1162/105474698565659
Experiments
Tasks
Findings

How do different locomotion interactions (real-world walking, joystick, virtual turning of the head) affect going through a virtual maze?

Variables and Constants

    Biomechanical Symmetry
  • anthropometric - joystick has none, while the head rotation in real-turn condition has middle fidelity because the head moves. walking normally has full fidelity.
  • kinematic - real-world walking is perfect, while real-turning of the head for rotation is middle. joystick has none.
  • kinetic - real-world walking feels large vertical and sheer ground forces on the entire body resulting in perfect fidelity. real-turn with the head specifying rotation has little forces exerted on it, but the rotation of the head is moving similarly as though it we
    Control Symmetry
  • transfer function - walking & rotating in real-life versus joystick for rotation and constant translation forward, versus heard rotation for rotation
  • dimensional - walking is x & y, while the two other techniques are x, y & rotation.
Independent Variables
  • locomotion technique - real-world walking, joystick for rotation & constant forward movement, and head rotation for rotation with constant forward movement
Constants

Since the display is the same throughout the experiment, display form factor, update rate, frame rate, FOV, among others, are held constant.

System Info

Displays
  • head-mounted display - virtual research fs5: display consisting of two crts, one for each eye. the ico output board converts the sgi graphic images to the 800 (horizontal) 3 486 (vertical) resolution of the fs5. each display in the fs5 is refreshed in full color at 60 hz in fie
Input Hardware
  • head tracker - has a video camera looking at lights on the head, with goniometer
  • joystick - handles rotation for some of the conditions
Software
None

The graphics computer is a Silicon Graphics (SGI) Indigo2, High-Impact computer with an ICO multichannel output board. This computer generates a stream of shaded, texture-mapped images for each eye. The six mazes used in the experiment were created using the 3D modeling program Strata StudioPro Blitz on a Macintosh and were then exported to the SGI.

Participant Info

There were `7 undergrads and 5 graduates, before the drop outs of the trials.

Total # Age Range Gender Balance
18 -

The participant has to go through a virtual maze around 3m x 4 m in dimension.

Interaction and Environment

Interface

The interaction varied depending on the technique. There was a guide in the virtual maze to go, and the walking condition directly mapped the user with their camera tonavigate. The virtual turn condition had the joystick control the rotation, with forward movement being constant. The real turn condition had a stationary user rotating their heads for turning, with forward movement.

The maze was 3m x 4m, with the average path length of 10m. The walls of the maze were textured in brick and stood at 3m. There were 6 different mazes. 12 objects were dispersed in all 6 mazes, with 3 of them having only one object inside.

Dimensionality Scale Density Visual Realism
3D Medium Medium Not reported
Metrics

  • errors - errors are difference in angle from the ideal path to the path taken for each turn
  • cybersickness - the subject indicated how motion sick he/she felt on a scale of 1 (‘‘no symptoms’’) to 5 (‘‘very sick’’).
  1. There was a significant interaction between anthropometric, kinematic, kinetic, transfer function, dimensional, and locomotion technique on errors for a travel - maneuvering task.

    Walking compared to turning with joystick resulted in less errors in going through a maze.

    Specificity: Neither
    A post hoc Tukey test revealed only a significant difference between the Walk and Visual Turn modes (p 5 0.041).

  2. There was a significant interaction between anthropometric, kinematic, kinetic, transfer function, dimensional, and locomotion technique on cybersickness for a travel - maneuvering task.

    Virtual turning, head-turning and real-world walking resulting in the most, middle and least in causing cyber-sickness in walking through a virtual maze.

    Specificity: Neither
    According to a one-way ANOVA, there was an effect of locomotion mode, F(2, 34) = 3.29, p = .049.

How do different locomotion interactions (real-world walking, joystick, virtual turning of the head) affect going through a virtual maze with no decision points throughout the maze, and improvements in the techniques?

Variables and Constants

    Biomechanical Symmetry
  • anthropometric - joystick has none, while the head rotation in real-turn condition has middle fidelity because the head moves. walking normally has full fidelity.
  • kinematic - real-world walking is perfect, while real-turning of the head for rotation is middle. joystick has none.
  • kinetic - real-world walking feels large vertical and sheer ground forces on the entire body resulting in perfect fidelity. real-turn with the head specifying rotation has little forces exerted on it, but the rotation of the head is moving similarly as though it we
    Control Symmetry
  • transfer function - walking is 1:1 position to position. the joystick and head-turning techniques are & rotating in real-life versus joystick for rotation and constant translation forward, versus heard rotation for rotation
  • dimensional - joystick and head rotation techniques are 1:1 push to position, 1:1 tilt to rotation. real-world walking is x,y, and rotation.
Independent Variables
  • locomotion technique - real-world walking, joystick for rotation & forward tilting for forward movement, and head rotation for rotation with joystick for forward movement
Constants

Since the display is the same throughout the experiment, display form factor, update rate, frame rate, FOV, among others, are held constant.

System Info

Displays
  • head-mounted display - virtual research fs5: display consisting of two crts, one for each eye. the ico output board converts the sgi graphic images to the 800 (horizontal) 3 486 (vertical) resolution of the fs5. each display in the fs5 is refreshed in full color at 60 hz in fie
Input Hardware
  • head tracker - has a video camera looking at lights on the head, with goniometer
  • joystick - handles rotation for some of the conditions
Software
None

The graphics computer is a Silicon Graphics (SGI) Indigo2, High-Impact computer with an ICO multichannel output board. This computer generates a stream of shaded, texture-mapped images for each eye. The six mazes used in the experiment were created using the 3D modeling program Strata StudioPro Blitz on a Macintosh and were then exported to the SGI.

Participant Info

Undergraduates who participated in experiment 1.

Total # Age Range Gender Balance
28 -

The participant has to go through a virtual maze around 3.2m x 6m in dimension.

Interaction and Environment

Interface

The interaction varied depending on the technique. The walking condition directly mapped the user with their camera to navigate. The virtual turn condition had the joystick control the rotation and forward movement. The real turn condition had a stationary user rotating their heads for turning, with forward movement done through joystick.

The participant went through a maze with no decision points.

Dimensionality Scale Density Visual Realism
3D Small Medium Medium
Metrics

  • errors - errors are difference in angle from the ideal path to the path taken for each turn
  • cybersickness - the subject indicated how motion sick he/she felt on a scale of 1 (‘‘no symptoms’’) to 5 (‘‘very sick’’).
  1. There was a significant interaction between anthropometric, kinematic, kinetic, transfer function, dimensional, and locomotion technique on errors for a travel - maneuvering task.

    Walking led to less errors than virtual turning with a joystick navigating through a maze.

    Specificity: Neither

  2. There was a significant interaction between anthropometric, kinematic, kinetic, transfer function, dimensional, and locomotion technique on errors for a travel - maneuvering task.

    Walking led to less errors than virtual turning with a joystick navigating through a maze.

    Specificity: Neither