Immersive VR Environments to Induce and Evaluate Cognitive Fatigability

Objective: This study evaluates the utility of immersive virtual environments for objectively studying individual differences in the susceptibility to develop cognitive fatigue in healthy controls while performing instrumental activities of daily living (IADL) in two phases. Phase 1 aims to test functionality and user experience of the virtual reality (VR) experience; and phase 2 aims to evaluate the level of fatigue experienced after participating in a VR experience as measured by the Visual Analog Scale-Fatigue (VAS-F). The primary goal of the protocol is the study of individual differences in subjective fatigability associated with grocery shopping using immersive Virtual Reality as a research platform. The secondary objective of the protocol is to identify objective measures of cognitive fatigue.

Primary Endpoint Phase 1: The phase 1 primary dependent measure is the total count of the number of times, after completing the grocery shopping training exercise, the subject required research staff to explain how to use the controller, how to move or inspect objects, and/or how to move from one location to another location in the grocery store environment. Secondary Endpoint for Phase 1: the ocular and general symptoms score from the virtual reality symptom questionnaire (Ames et al., 2005); and the total score from the presence questionnaire (Regenbrecht et al., 2002).

The Primary Endpoint for Phase 2 primary:Total score of VAS-F (Lee et al., 1991).

The Secondary Endpoint for Phase 2;Self-reported cognitive load score measured by the NASA-TLX (Hart et al., 1988), eye-tracking data (e.g., percent eye-closure, fixation length, blink rate) and task performance measures (e.g. shopping list total correct item selection score, shopping list total incorrect item selection score, average item-selection time score).

Study Population: The study plans to enroll a total of 84 (24 in phase 1 and 60 in phase 2) healthy participants from the Washington Metropolitan area between ages 18-75.

Key Inclusion/Exclusion Criteria: Both study phases utilize the same key inclusion/exclusion. Participants must be between the ages (Bullet) 18 and 75 years. Key exclusion criteria include: visual impairment in the form of limited or reduced 3D vision, oculomotor disorder/dysfunction, susceptibility to visually-induced seizures, iritis, frequent headaches/migraines, severe sensitivity to motion sickness and any impairment in the use of arms/hands/fingers.

Design: All participants will complete the study at the NIH main campus clinical center. This is a two-phase research study. All participants will be screened for physical health, cognitive and visual symptoms via self-report. Phase 1 combines a traditional user experience design that utilizes qualitative, quantitative, and observational methods to test the software functionality, user interface, and realism of the immersive experience and a randomized control trial to estimate of effectiveness of the fatigue induction tasks. Phase 2 utilizes a 3-arm randomized control trial, where participants will be randomized into one of three virtual shopping experiences, a control condition (exploration of the shopping environment), a cognitively challenging condition (standard shopping list completion task), or a cognitive and emotionally challenging condition (shopping list with interruptions, interference, and rework). All participants will complete questionnaires and cognitive tests pre-and-post VR environment. Questionnaires related to target processes (fatigue and workload) are administered in the environment. After completing post-environment questionnaires, the participants are provided an opportunity to give verbal feedback about the experience and to note any observed problems with the interface or use of controllers, as well as their VR experience.

Study Duration: Phase 1 is expected to be completed in a period of 8 months from opening of enrollment to completion of data analysis. Phase 2 will require 12 months from opening of enrolment until data analysis.

Participant Duration: Phase 1 is completed in one visit to the NIH campus, Phase 2 may be completed in 1 or 2 visits to the NIH campus within the same week or consecutive weeks.