Reduction of Forgetting by Contextual Variation During Encoding Using 360-Degree Video-Based Immersive Virtual Environments

TL;DR

Context-dependent forgetting poses challenges for education. This study tests reinstatement and decontextualization using 360-degree video–based IVEs to improve realism and accessibility in VR. Results show no robust reinstatement effect but a significant decontextualization effect, where learning across varied IVEs reduces forgetting relative to constant contexts. The findings support using VR context variation to bolster memory and highlight future work on presence and social-context manipulation to optimize VR-based learning.

Abstract

Recall impairment in a different environmental context from learning is called context-dependent forgetting. Two learning methods have been proposed to prevent context-dependent forgetting: reinstatement and decontextualization. Reinstatement matches the environmental context between learning and retrieval, whereas decontextualization involves repeated learning in various environmental contexts and eliminates the context dependency of memory. Conventionally, these methods have been validated by switching between physical rooms. However, in this study, we use immersive virtual environments (IVEs) as the environmental context assisted by virtual reality (VR), which is known for its low cost and high reproducibility compared to traditional manipulation. Whereas most existing studies using VR have failed to reveal the reinstatement effect, we test its occurrence using a 360-degree video-based IVE with improved familiarity and realism instead of a computer graphics-based IVE. Furthermore, we are the first to address decontextualization using VR. Our experiment showed that repeated learning in the same constant IVE as retrieval did not significantly reduce forgetting compared to repeated learning in different constant IVEs. Conversely, repeated learning in various IVEs significantly reduced forgetting than repeated learning in constant IVEs. These findings contribute to the design of IVEs for VR-based applications, particularly in educational settings.

Figures (9)

• Figure 1: Virtual reality (VR) offers the benefit of learning experiences in various locations, all from the comfort of our own rooms. In this study, we used VR to examine the effect of repeated learning under various environmental contexts, which made forgetting harder (decontextualization effect). In a Tagalog-Japanese pair learning task, the condition where repeated learning was conducted in diverse virtual environments significantly reduced forgetting compared to that where repeated learning was conducted in a single virtual environment.
• Figure 2: Experimental design. All participants studied 20 Tagalog-Japanese pairs, took five retrieval practices, and had a final test two days later. In the Constant-NotReinstated condition, a participant performed an initial study, five retrieval practices in a constant IVE, and a final test in a new IVE. In the Constant-Reinstated condition, a participant performed an initial study, five retrieval practices in a constant IVE, and a final test in the same IVE. In the Varied condition, a participant performed an initial study and five retrieval practices in IVEs different from each other, and then a final test was conducted in a new IVE. We prepared seven IVEs and counterbalanced them among the participants. The number of words correctly recalled on the five retrieval practices and final test and forgetting from Day 1 to Day 2 were measured and compared between participants in the three conditions.
• Figure 3: Participants engaged in a memory task to memorize 20 Tagalog-Japanese pairs of words. (a) During learning, the Tagalog words were presented in the left box in front, while their Japanese translations were presented in the right box at a rate of 5 s/pair. (b) Only the Tagalog words were presented during testing, with a question mark in the right box. The participants responded orally with the Japanese translation corresponding to the Tagalog word.
• Figure 4: Shots of 360-degree videos used as environmental context. From top left: Beach, Pond, River, Glassland, Shrine, Park, and Building. The shots were taken by a KANDAO Qoocam8K camera with a resolution of 7680 $\times$ 3840, 30 fps, and monoscopic.
• Figure 5: Mean number of correct answers obtained in the five retrieval practices and the final test. Error bars represent the 95% confidence intervals. Three ANOVA for the number of correct responses obtained in the first retrieval practice (RP1), the change in the number of correct responses during the five retrieval practices (acquisition), and the number of correct responses in the final test (retention) showed no significant differences between the conditions.