Usability of an embodied CAVE system for spatial navigation rehabilitation in mild cognitive impairment

Navigation and spatial memory impairments are reported by individuals with mild cognitive impairment (MCI), which is considered a transitional stage between normal aging and dementia. Spatial navigation is an embodied process that requires both bodily (e.g., motor commands, proprioception) and cognitive (e.g., decision-making, mental rotation) information. Immersive virtual reality (IVR) is a powerful tool that recruits this information as in real-world navigation. Given the crucial impact of spatial navigation impairments on daily life, its rehabilitation should be a primary objective of research. Nevertheless, current IVR solutions for spatial navigation rehabilitation in MCI are still in their infancy. In this usability study, eight MCI patients tested an IVR spatial navigation training demo and interacted with the CAVE using active stereo glasses, a foot-motion pad, and a joypad. During the demo, thoughts and issues were reported with the thinking-aloud procedure. Questionnaires about usability, presence, and cybersickness were administered at the end of the experience. Our results show that the first version of this system is usable by the patients even if the majority had no experience with PC/IVR. The system provided a moderate sense of spatial presence and very low negative effects. Issues found during the thinking-aloud procedure concerned visual aspects which affected the interaction user-system. Participants needed to practice more with the foot-motion pad even though the overall experience was positively evaluated. By identifying critical aspects, an improved version of the current system has been released.