Exploring the Use of Virtual Reality in Episodic Memory Research

Episodic memory (EM) allows us to receive and retain information about events, where those events happened and when they happened. This knowledge defines humans and if it deteriorates it affects everyday functioning. As such it is important to assess it in a way that reflects our everyday experiences. Evidence suggests that an ecologically valid way of testing EM is needed. One way of achieving this is by using virtual reality. The present thesis aimed to explore how HMD-VR can be used to test EM in an ecologically valid fashion and to attempt to conceptualise and understand the nature of long-term EM as events.Experiments 1 and 2 explored how EM for events differed to EM for non-events or static objects, the latter being stimuli often used in EM research. Additionally, due to the majority of research focusing just on encoding and retrieval, leaving out memory consolidation, the experiments explored how sleep-dependant memory consolidation affects EM. Events were better retrieved then non-events in several tasks. Additionally, results showed that EM for events might not rely on enhanced encoding but on preferential consolidation, as no difference between event- and non-event-retrieval was observed in EM accuracy immediately after encoding, yet events were significantly better retrieved than non-events after a 24-hour period. Experiments 3 and 4 explored how EM performance in HMD-VR differs to Desktop-VR, a system that is traditionally used in the field of memory research. The general prediction was that EM performance would be more accurate in HMD-VR, compared to Desktop-VR. The results were mixed, with Experiment 1 showing no differences in performance while Experiment 2 only partly supporting the prediction by showing better EM performance in some of the measures. The thesis proposes HMD-VR to be a valid, if not more accurate, tool for exploring daily-life-like EM.