An immersive virtual reality serious game set for the clinical assessment of spatial attention impairments: Effects of avatars on perspective?

Background: Hemineglect (HN) is a post-stroke condition, frequently defined as an impairment in finding spatial targets within an egocentric frame of reference, where the stimulus is coded relative to the self. However, the egocentric reference frame can change with the presence of another person. Immersive virtual reality (IVR) offers several advantages over paper-and-pencil tests typically used to assess HN, such as a realistic and controlled environment, standardised stimulus presentation, and sensitive response acquisition. We developed a new serious game in IVR to assess HN. Here we investigated (1) the feasibility and user experience of this serious game, and (2) the effect of the presence of an avatar on HN.

Methods: We first tested a group of 61 control individuals (CI), followed by a group of post-stroke 11 individuals without HN (SI:HN-), 6 with HN (SI:HN+), and 17 resampled age matched group of control individuals (CI). All participants performed the "Peach test", which required them to find and respond to a target presented among distractors, either alone or in the presence of an avatar. We measured response time (RT) and omissions. The SI:HN- and SI:HN + groups also completed a paper-and-pencil test for HN and a user experience questionnaire.

Results: The first analysis of results with CI showed no differences in responding to the target when in ipsi- compared to contra-lateral spaces, nor in peri- compared to extra-personal spaces. There were also no differences in responding to the target in the no-avatar condition relative to the two avatars conditions. In the second analysis, SI:HN + were slower than SI:HN- and CI. Although an interaction between group and Laterality was predicted, the results showed that there was no Laterality effect for any of the groups. An interaction between group and proximity, showed that both SI groups were slower in the extra- compared to peri-personal spaces. The user experience was globally positively rated by the SI.

Conclusion: We developed a serious game in IVR for the assessment of HN. Although most our findings were inconclusive, the Peach test showed excellent user experience results.Trial registration http://www.clinicaltrials.gov ; Unique identifier: NCT04694833, Date of registration: 11/24/2020.