Usability, User Experience, and Acceptability of the Trail Making Test in Virtual Reality in Younger and Older Adults
Immersive virtual reality (VR) adaptations of neuropsychological tests change how a test operates. Before their scores are interpreted, the individuals they are intended to assess should find them usable, acceptable and tolerable, and for older adults this evidence is usually missing. This study evaluated the experience of the Trail Making Test in Virtual Reality (TMT-VR), a head-gaze adaptation of the Trail Making Test that requires no hand-held controller, in 47 younger (20-38 years) and 44 older adults (64-81 years). After the task, participants rated usability, pragmatic and hedonic user experience, acceptability, and cybersickness. The study had three aims: to compare the two age groups on these ratings; to examine whether the ratings were associated with age group, gaming and technology experience, and whether cybersickness was associated with motion sickness susceptibility; and to examine whether the ratings were related to TMT-VR completion and error-adjusted times. Both groups rated the TMT-VR as highly usable, acceptable and pleasant to use. Older adults gave slightly lower usability and pragmatic ratings, but neither the age-group differences nor the associations with age group or previous experience were statistically significant after correction. Cybersickness was low, with 38 of the 91 participants reporting no symptoms; it did not differ between the age groups and was not associated with motion sickness susceptibility. No correlation between the ratings and TMT-VR performance survived correction. The TMT-VR with head-gaze selection is therefore usable, acceptable and well tolerated by older as well as younger adults. Because the ratings were favourable across the whole range of TMT-VR scores, slower or less accurate performance is unlikely to reflect difficulty with the interface.