Summary
Therapeutic interventions have not yet been shown to demonstrate restorative effects for declining long-term memory (LTM) that affects many healthy older adults. We developed a virtual reality (VR) spatial wayfinding game (Labyrinth-VR) as a cognitive intervention with the hypothesis that it could improve detailed, high-fidelity LTM capability. Spatial navigation tasks have been used as a means to achieve environmental enrichment via exposure to and learning about novel and complex information. The engagement has been shown to enhance learning and linked the vitality of the LTM system in the brain. In the current study, 48 older adults (mean age 68.7 ± 6.4 years) with average cognitive abilities for their age were randomly assigned to 12 hours of computer gameplay over four weeks in either the Labyrinth-VR or the placebo control game arms. Promptly before and after each participant’s treatment regimen, high-fidelity LTM outcome measures were tested to assess mnemonic discrimination and other memory measures. The results showed a post-treatment gain in high-fidelity LTM capability for the Labyrinth-VR arm, relative to placebo, which reached the levels attained by younger adults in another experiment. This novel finding demonstrates the generalization of benefits from the VR wayfinding game to important and untrained LTM capabilities. These cognitive results are discussed in light of relevant research for hippocampal-dependent memory functions.

Innovative VR tools and techniques
● High-fidelity memory depends upon the flexible association of diverse bits of information for facts and events that are remembered in distinct and detailed terms, and it can be conceptualized in terms of source, associative, and autobiographical memory, as well as mnemonic discrimination as a behavioral task to operationalize pattern separation processes.
● Applying video games as cognitive interventions to impact behavior and brain function is an emerging method in translational neuroscience research.
● By using an HMD VR drives greater engagement and increased subsequent success for participants, comparing to their performance on the same task using a flat-screen-monitor version.
● Older adults with average cognitive performance for their ages demonstrated reliable gains in an untrained measure of high-fidelity LTM retrieval relative to matched older adults who played placebo control games.
● The results suggest that a cognitive intervention can remediate age-related deficits in high-fidelity LTM experienced by older adults.
● HMD VR makes multidimensional demands for a player’s engagement with the game.
● Complex environs (i.e., environmental enrichment) results in improved capability for hippocampal-dependent LTM.

VR in education
● Declining long-term memory (LTM) impacts diverse aspects of cognitive performance and overall quality of life for many healthy older adults.
● The potential to stimulate plasticity and up-regulate function in the hippocampus has been demonstrated in rodent model studies using a spatial exploration of novel, complex environs. Spatial navigation tasks have an impact on exposure and learning of novel and complex information that have been linked to the vitality of the memory system in the brain.
● Among three groups of healthy older adults showing equivalent mnemonic discrimination ability at their baseline tests, only the post-treatment group that engaged in Labyrinth-VR showed LDI performance equivalent to the level of younger adults.
● Night-time and fog-shrouded game trials, when color, texture, and perspective for route landmarks were substantially degraded, were the most difficult challenges for the accuracy of participants’ allocentric navigation in the new neighborhoods. All of these elements in the Labyrinth-VR game were expected to contribute to participants’ engagement and interaction with the wayfinding task so as to optimize their opportunity for enrichment by increasing demands on hippocampal-dependent learning.