Navigational object-location memory assessment in real and virtual environments: A systematic review.

Navigational object-location memory (OLM) is a form of spatial memory involving actual or virtual body displacement for repositioning previously encoded objects within an environment. Despite its potential for higher ecological validity measures, navigational OLM has been less frequently assessed than static OLM. The present systematic review aims to characterize the methodology and devices used for OLM assessment in navigational real and virtual environments and synthesize recent literature to offer a comprehensive overview of OLM performance in both pathological and non-pathological adult samples. A search through four different databases was conducted, identifying 39 studies. Most studies assessed navigational OLM in healthy adults by 2-dimensional or 3-dimensional computerized tasks, although immersive Virtual Reality (VR) devices were also frequently employed. Small environments and objects with high-semantic value were predominantly used, with assessment mainly conducted immediately after learning through free-recall tasks. The findings revealed that healthy samples outperformed clinical ones in navigational OLM. Men showed superior performance compared to women when cues or landmarks were used, but this advantage disappeared in their absence. Better results were also noted with shorter intervals between learning and recall. Fewer OLM errors occurred in real environments compared to both immersive and non-immersive VR. Influences of environmental features, object semantics, and participant characteristics on OLM performance were also observed. These results highlight the need for standardized methodologies, the inclusion of a broader age range in populations, and careful control over the devices, environments, and objects used in navigational OLM assessments.