## 4 Discussion
Previous research that assessed visuospatial memory employing a niVR device found that although healthy participants exhibited more pronounced learning effects than epilepsy patients, both groups demonstrated evidence of learning progress [49]. Spatial memory and navigation can be improved using a memory reactivation paradigm, such as the CL-TMR [37]. In fact, CL-TMR increases fast spindle activity in the frontal cortex, suggesting a brain activity enhancement during sleep and aiding memory consolidation. Complementing this, a recent study found that memory reactivation during sleep induced an increase in theta and spindle oscillations, which were related to memory processing [50]. Related to spatial navigation, the fact that higher fast spindle activity was linked to more spatial navigation efficiency in the CLM-TMR condition suggests that cerebral activity during sleep can also facilitate spatial navigation abilities. The integration of iVR with neuroimaging and neurophysiological technologies, as demonstrated in the reviewed studies, enhances the ecological validity of visuospatial memory assessment by offering controlled environments while assessing brain function. The results of this review highlight the contribution of iVR in combination with EEG and RINRS in elucidating the neural substrates of visuospatial memory processes, including encoding, retrieval, and navigation. These methods have revealed robust associations between brain activity in key regions such as the prefrontal cortex, MTL, and PC with task performance, emphasizing the neural correlates of memory under diverse contextual conditions. Stress, environmental design, and stimuli properties exert a substantial influence on performance and brain dynamics. The findings also highlight the need for future research that extends these approaches to clinical cohorts and integrates real-world task demands. This will allow for further validation and refinement of the role of iVR in cognitive neuroscience and neuropsychology. It is important to acknowledge the limitations of this present systematic review, which may influence the interpretation of the findings. There is a potential risk of omitting relevant studies that were not included in the databases analyzed, which could result in an incomplete representation of the existing research landscape. Achieving consistency among the findings of the limited number of studies included presents a challenge, primarily due to the heterogeneity of their objectives, methodologies, and contexts. These variations can complicate the synthesis of the results and may limit the generalizability of the conclusions. Nevertheless, this review offers an initial framework to understand the brain dynamics involved in iVR-based visuospatial memory tasks, providing a meaningful contribution to this new field by elucidating the neural substrates of visuospatial memory as assessed through iVR-based tasks, providing valuable insights into this cognitive process within more ecologically valid and realistic environments. Furthermore, it provides a critical baseline for researchers entering this field, highlighting prevailing methodologies and emergent trends. This, in turn, provides a foundation for the conceptualization of future studies and the refinement of research methodologies.