A within-subject study to investigate the influence of Virtual Reality on subsequent episodic memory

Animal studies have shown that exploring a novel environment facilitates learning (e.g., Davis, 2004). According to two influential models (Düzel et al., 2010; Lisman & Grace, 2005), novelty triggers dopamine release in the substantia nigra and the ventral tegmental area, which in turn promotes hippocampal learning by lowering the threshold for long-term potentiation. This novelty-induced neuroplasticity operates both during exposure to the novel environment and for up to 10 minutes afterward (Straube et al., 2003). There is even evidence suggesting the possibility of longer-term effects (Tang & Zou, 2002). In humans, novelty also appears to enhance learning (Tulving & Kroll, 1995), but the available evidence remains limited, particularly regarding the long-term beneficial effects of novelty exposure on learning. Slightly more than a decade ago, Schomaker et al. (2014) showed that exploring a novel virtual environment led to better recall performance on a verbal memory task administered after exploration, compared to exploring a familiar environment. Since then, several studies have reported contradictory findings (e.g., Quent & Henson, 2022). In our team, we failed to replicate this effect using similar experimental designs (see Aaron et al., 2024; Servais et al., 2024). Instead, these studies revealed a session order effect: participants showed better memory performance after the first session in which they explored a virtual reality environment, regardless of whether the environment was novel or familiar. We therefore turned our attention to the effect of virtual reality itself on memory. In a previous study, we showed that memory performance was better after exploring a virtual environment compared to watching a documentary about a natural environment (Servais & Bastin, 2025). However, this study included potential confounding variables, such as active exploration (VR) versus passive viewing (watching a documentary). The aim of the present study is to better understand how virtual reality influences learning in humans. We hypothesize that virtual reality constitutes a novel experience, distinct from everyday activities, and that it may represent a specific form of novelty that positively influences memory during initial exposure. To do so, participants will take part in three sessions conducted within a 15-day period. The order of the sessions will be counterbalanced across participants: - Session 1: Participants will actively explore a virtual environment (one of the Meta VR Nature Trek environments) using an Oculus Rift virtual reality headset. Following exploration, participants will complete a memory task (learning a list of 20 words presented using OpenSesame, followed by immediate free recall after a brief 2-minute simple mental arithmetic distractor task). After the memory test, participants will complete a questionnaire developed at ULiège to assess the sense of presence experienced during virtual reality. They will also complete a cybersickness questionnaire, as well as a series of questionnaires assessing different aspects of the exploration (motivation, emotions, perceived novelty of the environment, novelty of the technology used, interest, etc.). - Session 2: Participants will explore another Meta VR Nature Trek environment, but this time in a desktop version displayed on a computer screen (i.e., without the VR headset). After exploration, participants will complete a memory task similar to that of Session 1, using a different word list. They will then complete the same questionnaires as in Session 1. - Session 3: Participants will watch a video recording of the exploration of another Meta VR Nature Trek environment (passive viewing on a computer screen). After viewing, participants will complete a memory task similar to those in Sessions 1 and 2, using a different word list. They will then complete the same questionnaires as in Sessions 1 and 2. If active exploration of a novel environment improves learning for subsequent non-related material, we expect memory performance (i.e., the number of words recalled) to be higher after exploring an environment using a virtual reality (VR) headset and exploring an environment on a computer desktop compared to passively watching a recorded video of an exploration. Moreover, if the VR itself boosts memory beyond the active exploration of a novel environment, we expect memory performance to be higher after exploring a novel environment in a VR headset compared to exploring an environment on a computer desktop.