In Augmented Reality (AR) applications, virtual objects are often placed near to real-world objects like walls, furniture or bulletin boards. Little is known about how users mentally represent this spatial relationship between virtual and real objects - and how spatial memory is affected if the reference objects in the real world are moved.

This study investigates how changes in the position of physical reference objects influence users' memory for the locations of virtual objects. Users viewed and rated 18 AI-generated images presented as virtual objects via AR (Meta Quest 3) in a fully furnished room while incidentally memorising the objects' locations. After a delay of 2-3 days, participants returned to the room where some of the physical furniture had been moved. They had to place the virtual objects at the remembered locations.

Our results show that participants mentally represent the locations of the virtual objects in relation to nearby physical reference objects, even if the locations are task-irrelevant: When the physical reference objects are moved, they placed the virtual objects at locations that are moved in the same way as the underlying furniture.

This research lays the groundwork for follow-up studies that examine the use and influence of properties of the physical space in tasks where users create their own spatial layouts of virtual objects. Additionally, it will inform the design of AR applications that rely on connections between the real and virtual world under real-world variability.