As the global population steadily ages, the preservation and enhancement of cognitive functions in older adults have become critical challenges for healthcare and scientific communities worldwide. Demographic projections by the United Nations indicate that by the 2070s, the number of individuals aged 65 years or older will surpass 2.2 billion, exceeding the population of children under 18. This demographic shift is particularly stark in countries like Japan, where nearly 29% of the population has already reached this age threshold. In light of these transformations, innovative strategies targeting cognitive decline prevention and rehabilitation are urgently needed to enhance quality of life and autonomy among elderly populations.
Among the emerging interventions, olfactory stimulation—the engagement of the sense of smell—has attracted rising scientific interest due to its unique neural pathways and connection to memory and emotion centers in the brain. Unlike other sensory modalities, olfactory signals have direct and privileged access to the limbic system, including the hippocampus and amygdala, key regions implicated in memory encoding, emotional processing, and spatial cognition. This direct pathway offers a strategic target for cognitive training approaches aimed at mitigating age-related declines in memory and executive functions.
Building on this theoretical framework, a multidisciplinary team from the Institute of Science Tokyo, University of the Arts London, Bunkyo Gakuin University, and Hosei University has pioneered the world’s first olfactory-based virtual reality (VR) cognitive training protocol specifically designed for older adults. Their groundbreaking research, recently published in the esteemed journal Scientific Reports, details an innovative experimental study combining immersive VR technology with precise olfactory delivery systems to challenge and stimulate multiple cognitive domains simultaneously.
Virtual reality offers an unparalleled platform for creating highly controlled, immersive sensory environments that can closely mimic real-world conditions while allowing for precise manipulation and monitoring of stimuli. Professor Takamichi Nakamoto of Science Tokyo highlights the advantage of this approach: “By integrating goal-oriented tasks with real-time feedback within the virtual environment, our olfactory VR intervention can foster heightened cognitive engagement, potentially amplifying neuroplasticity and therapeutic outcomes.”
The developed system employs a specialized olfactory display capable of emitting targeted scent compounds in synchrony with VR gameplay. Participants begin by interacting with a virtual stone statue that releases a distinct scent accompanied by a visual cue—a white vapor cloud—which serves to reinforce multisensory encoding of the odor. This initial phase aims to establish a robust odor memory trace by coupling olfactory stimuli with visual landmarks, thereby enhancing recognition and retention.
Following the encoding phase, participants navigate a complex virtual landscape, guided subtly by faint olfactory cues emitted from their headset-integrated scent delivery system. This navigation task challenges not only spatial cognition but also the integration of olfactory input with visuospatial processing. Through this dual engagement, the protocol targets neural networks responsible for memory retrieval, attention, and spatial navigation, domains known to deteriorate with advancing age.
At the culmination of the experience, participants face an olfactory discrimination challenge: three differently scented vapor clouds emerge from a virtual stone lantern, and individuals must identify the one matching the original stimulus. This task demands working memory retrieval, fine olfactory discrimination, and decision-making processes, thereby reinforcing multiple layers of cognitive function in a single session.
Professor Nakamoto elaborates on the scientific rationale: “Each phase of the VR olfactory training is carefully designed to activate and exercise overlapping yet distinct neural substrates. From sensory encoding to spatial memory integration and olfactory discrimination, the multimodal challenge encourages synaptic plasticity across memory, sensory, and executive circuits in the aging brain.”
The empirical evaluation involved thirty older adults ranging in age from 63 to 90 years. Remarkably, even a brief, twenty-minute session of olfactory VR gameplay induced measurable improvements in visuospatial rotation and memory abilities. Objective assessments included the Hiragana Rotation Task—a visuospatial assessment where participants discern whether rotated Japanese characters remain unchanged—and a word-based spatial memory recall test, wherein participants memorize and recall word positions within a patterned grid.
Statistically significant gains were observed post-intervention: Hiragana task scores improved from a range of 19–82 to 29–85, while spatial recall performance improved from 0–15 to 3–15. These findings suggest that olfactory VR training can swiftly augment neural processes supporting visuospatial cognition and working memory, domains critically affected in dementia and other neurodegenerative conditions.
Beyond immediate cognitive benefits, this research paves the way for practical applications in cognitive rehabilitation and dementia prevention. As olfactory dysfunction often precedes cognitive decline in neurodegenerative diseases, leveraging scent-based VR training embodies a novel preventative approach. Furthermore, the modular architecture of the VR and olfactory systems offers scalability, adaptability, and personalization potential for future interventions tailored to diverse aging populations.
Despite the promise, widespread implementation faces technological and economic hurdles, primarily related to the accessibility and cost of precise olfactory display hardware. The research team underscores the importance of ongoing innovation to create more affordable and user-friendly scent delivery mechanisms that can be integrated seamlessly with VR platforms. Advances in material science, micro-encapsulation, and vaporization technology are expected to gradually overcome these challenges.
This study exemplifies the transformative power of cross-disciplinary collaboration, uniting neuroscience, virtual reality technology, and sensory science to address pressing societal health issues. Institute of Science Tokyo, established in late 2024 through the merger of Tokyo Medical and Dental University and Tokyo Institute of Technology, continues to spearhead such endeavors with its mission to “Advance science and human wellbeing to create value for and with society.”
Looking forward, the combination of carefully tailored olfactory stimuli with immersive VR environments represents a frontier with broad applications—not only in cognitive aging but also in mood regulation, sensory rehabilitation, and even neuropsychiatric disorder management. As more extensive clinical trials and longitudinal studies accumulate, olfactory VR may well emerge as an integral component of holistic brain health programs for older adults globally.
Subject of Research: Not applicable
Article Title: Exploring the effects of olfactory VR on visuospatial memory and cognitive processing in older adults
News Publication Date: 28-Mar-2025
Web References: http://dx.doi.org/10.1038/s41598-025-94693-9
References: Scientific Reports, Volume 15, 2025
Image Credits: Institute of Science Tokyo
Keywords: Olfactory perception, Working memory, Memory disorders, Older adults, Spatial memory, Sensory stimuli
