Continuous Measurement Methods for Transient Physiological Discomfort in VR Locomotion

Paper Title

Continuous Measurement Methods for Transient Physiological Discomfort in VR Locomotion

Publication Info

• Topic area: Measurement methods for transient physiological discomfort in VR locomotion.
• Keywords: VR locomotion, transient discomfort, motion sickness, continuous measurement, sensory conflict, proprioception, tactile feedback, user elicitation, reliability, validity.

Background and Problem

• Problem / challenge: Current methods for assessing transient physiological discomfort in VR locomotion lack adequate granularity, accuracy, and real-time responsiveness. Discrete scales and physiological measurements fail to capture rapid fluctuations in discomfort caused by sub-locomotion changes.
• Significance: Addressing transient discomfort is critical for improving VR user experience, optimizing locomotion design, and enabling adaptive interventions to reduce discomfort.
• Motivation and related work: Previous studies have focused on long-term effects of motion sickness using discrete questionnaires and physiological signals, which are insufficient for capturing short-term discomfort dynamics. Continuous self-report methods from other domains offer inspiration but are not tailored for transient discomfort in VR locomotion.

Solution

• Proposed approach: Development of continuous measurement methods for transient physiological discomfort during VR locomotion, based on user-elicited designs and evaluations.
• Novelty:
  1. Identification of three preferred continuous measurement methods: ‘squeezing ball’, ‘sliding thumb’, and ‘rubbing thigh’.
  2. Comprehensive evaluation of these methods for reliability, validity, attention, presence, and workload.
  3. Design guidelines for continuous measurement methods tailored to transient discomfort in VR locomotion.
• Procedure and key techniques:
  • Conducted a user-elicitation study with 24 participants to design and select natural, low-load gestures for discomfort measurement.
  • Evaluated the top 3 methods in a controlled experiment with 18 participants, comparing them against the Fast Motion Sickness Scale (FMS) for reliability, validity, attention, presence, and workload.
  • Implemented methods using motion-capture systems and analyzed discomfort ratings during active and passive locomotion.

Results

• Concrete findings:
  • ‘Sliding thumb’ showed the highest reliability (Cronbach′s, α: 0.827–0.944), validity (shortest latency: 0.5–0.6s), and user experience (minimal distraction, high presence, low workload).
  • ‘Squeezing ball’ and ‘rubbing thigh’ also demonstrated good reliability (α: 0.718–0.946) and validity but had higher workload and lower attention scores.
  • Continuous measurement methods captured transient discomfort peaks and troughs, aligning with sensory-conflict theory and correlating moderately to strongly with FMS scores (r: 0.501–0.676).
• Advantage over baselines: Continuous methods provided higher temporal resolution and better real-time responsiveness compared to FMS, which disrupted VR experience and failed to detect transient discomfort changes.
• Experiments / evaluation:
  • Study 1: User-elicitation of 216 methods categorized into non-tactile, self-tactile, and external-tactile types.
  • Study 2: Evaluation of top 3 methods using repeated-measures design across active and passive locomotion, with metrics for reliability, validity, attention, presence, and workload.
• Limitations and future work:
  • Limited generalizability to standing postures and in-place locomotion.
  • Exclusion of scenarios where both hands are occupied.
  • Anchoring discomfort–rating correspondence during practice may affect robustness.
  • Uniform participant demographics (young, HCI/design backgrounds).
  • Focus on top 3 methods may overlook other viable designs.

Summary

This paper introduces continuous measurement methods for transient physiological discomfort in VR locomotion, addressing limitations of existing tools. Through user elicitation and experimental evaluation, three preferred methods—‘squeezing ball’, ‘sliding thumb’, and ‘rubbing thigh’—were identified, with ‘sliding thumb’ showing the best overall performance. Continuous methods demonstrated high reliability, validity, and responsiveness, capturing transient discomfort dynamics more effectively than discrete scales like FMS. These findings provide actionable design guidelines and highlight the utility of continuous measurement for optimizing VR locomotion experiences and mitigating discomfort.