The Method of Loci (MoL) is an ancient mnemonic technique in which one encodes information by associating it with a mentally imagined, familiar environment. Our pilot study with two virtual worlds found that the classic benefits of the MoL remain robust in our implementation that used virtual environments as memory palaces. The present study follows up on this finding by 1) adding a third virtual world and 2) instructing subjects to recall the list of objects without explicitly prompting them with the world in which the objects were encoded. All subjects were instructed to walk about each virtual environment as a unique list of 15 objects iteratively rendered in front of their avatar. Subjects under the MoL manipulation were briefed on the implementation and benefit of the strategy and permitted to volitionally place objects in locations of their choosing. Subjects in the control group were instructed to employ a fabricated mnemonic enhancement strategy, where they did not place the items. In line with our hypothesis, subjects in the MoL group were able to recall significantly more items and retain a greater degree of the temporal encoding order.

The Method of Loci (MoL) is a potent mnemonic technique that taps into humans' powerful spatial memory to bolster recall for non-spatial items. Therefore, individuals with better spatial memory abilities should be expected to enjoy a greater benefit from their use of the MoL. In this study, participants learned lists of items using a virtual reality (VR) based implementation of the MoL, and we then examined the relationship between an individual's ability to recall spatial layouts and their ability to recall items on the lists. Participants first familiarized themselves with three distinct VR environments through a token-collection task. They then learned a list of 15 items in each environment, by memorizing 3D objects that appeared sequentially in front of their avatars as they walked around the environments. We later asked participants to recall the lists of items in sequential order. To assess spatial memory, we also asked participants to pinpoint the locations of tokens and specific landmarks on a bird's-eye view map. Results showed a strong correlation between the number of items recalled and participants' spatial memory of the tokens and landmarks.

The environmental context in which a memory is encoded can impact its later accessibility by virtue of tagging the memory with unique retrieval cues. We examined whether distinctive virtual environments (VEs) could be used as a means to provide contextual support during the learning of two sets of easily confusable stimuli. Specifically, we taught participants the translations of 50 English words in two pre-experimentally unfamiliar languages: 10 were learned only in Swahili, 10 only in Chinyanja, and 30 in both languages. Participants in the Dual Context group learned each language in a different VE, whereas participants in the Single Context group learned both languages in the same VE. On Day 2, after the fourth VE learning session, participants’ ability to recall the Swahili and Chinyanja translations of the English words was tested outside of the VEs. One week later (Day 8), participants were reached by telephone and performed a surprise recall test assessing their long-term retention of the foreign words. Our results revealed that while the Single and Dual Context groups showed comparable recall performance when tested on Day 2, the Dual Context group exhibited significantly reduced forgetting when tested on Day 8. This finding showcases how distinctive learning contexts can protect newly acquired memories from succumbing to excessive interference and promote long-term retention. An additional fMRI dataset collected from a separate group of Dual Context participants during Day 2 cued recall should provide further insights into the mechanisms that underlie their memory advantage.

Connectivity across regions in the brain can be characterized as either functional (correlated fluctuations in activity as measured by resting-state fMRI data) or structural (white matter pathways as measured by diffusion MRI data). Emerging studies suggest that the connections across brain regions that make up distinct cognitive networks can partially explain individual differences in behavioral traits. Some theorize that a reliable benchmark of intelligence is the ability to identify subtle patterns across distantly related ideas. The Raven's Progressive Matrices (RPM), a pattern completion task, is one widely used measure of general fluid intelligence. Here, we use a combination of functional and structural connectivity metrics derived from a large MRI dataset [n=127] to examine the relationship between neural connectivity and RPM scores. We used a Support Vector Regression cross-validation procedure to assess the degree to which we could predict a subject's intelligence based on these connectivity values. We were able to account for 14% of the variance in individuals' intelligence scores when using specific combinations of functional and structural connectivity values.

We tested the effects of immersion (the sense of inhabiting the virtual world) and presence (the sense of embodying one's avatar) on long-term retention of information learned in virtual environments (VE). While VE are increasingly utilized in pedagogy, there is mixed evidence on the effects of presence/immersion. Some reported that increased presence/immersion resulted in better recall, while others reported the opposite. Most past research examined memory visual-spatially (testing recall of visual information about the VE itself), thus both memory and presence/immersion measures were based on the VE itself, making it difficult to disentangle the relationship between the two. We studied the effects of presence/immersion on verbal memory, thereby isolating the memory task from the VE upon which presence/immersion were based. Participants learned 40 Swahili and 40 Chinyanja vocabulary words over the course of four learning sessions in a richly featured VE. They were tested (cued by English translations) before each exposure, and later tested again outside the VE on Day 2 and Day 8. We found that individuals who reported higher levels of immersion showed significantly greater recall on Day 8 (M=.42, SD=.08), as compared to those reported low immersion (M=.17, SD=.06). However, there were no effects of presence. These results demonstrate that increased immersion, but not presence, during VE learning might facilitate long-term retention.