Extended Reality to Assess Short-Term Spatial Memory-A Comparative Study of Mixed Reality, Augmented Reality, and Virtual Reality.

A Mixed Reality (MR) application using an optical see-through headset was developed to assess short-term spatial memory. A study with 29 participants was conducted. Data from this study were compared to two previous studies using mobile Augmented Reality (AR) and Virtual Reality (VR) with headsets. When comparing the three technologies (MR, AR, VR) for the performance variables, there were no statistically significant differences for either the total number of correctly placed objects or the total number of attempts. However, the MR application required more time than the AR and VR applications in the evaluation phase and more time than the VR application in the learning phase. Our arguments for the longer time are the novelty of the MR application for the participants and the characteristics of the applications. The key results from the MR study include the following: (1) the objects used in the MR application were correctly positioned on a map, which implies that the memory acquired with the MR application is effectively transferred to the user's mental map; (2) for the performance variables, there were no significant differences in the results by gender; (3) and the usability rating decreased with computer experience. The results show that the MR application is effective for spatial memory assessment and was well rated by the participants. The three technologies, along with suitable hardware, are effective for spatial memory assessment. However, MR using optical see-through headsets offers advantages over mobile AR and VR using headsets, discussed in this publication.