Most people donning virtual reality (VR) goggles are seeking the thrill of being immersed in a fictitious video game world. But some are donning them for an entirely different experience: to help researchers identify those most at risk of developing Alzheimer’s disease.
We know that early detection of Alzheimer’s disease and other dementias can have a significant impact on the quality of life of the affected persons, through deployment of lifestyle changes and medications that can slow down disease progression. However, diagnosis has to be done through collecting biomarkers that are expensive and invasive and thus require sufficient indication of functional impairment.”
Manu Madhav, Neuroscientist, University of British Columbia
This leaves opportunity for non-invasive behavioral and cognitive assessments that can give clinicians another tool for early diagnosis – and that’s where VR comes into play.
As will be presented today at the annual conference of the Cognitive Neuroscience Society (CNS) in Boston, Mass., cognitive neuroscientists are increasingly turning to VR technology to develop innovative ways to assess cognitive decline. Their work builds off past research on the role of spatial memory in Alzheimer’s disease but takes the traditional 2-D tasks and transforms them into high-tech, 3-D immersive experiences. New data is finding significant age-related and disease-related differences in how individuals can navigate and locate objects within a VR space, in some cases linking cognitive impairments to build up of Alzheimer’s proteins in the brain.
Exploring spatial memory and navigation
About 1 in 13 people between the ages of 65 and 84 will develop Alzheimer’s disease, according to the National Institute on Aging, and that number is projected to rise as life expectancy increases. But for cognitive neuroscientist Tammy Tran, studying memory and Alzheimer’s disease is about more than statistics. Like so many people, she has had loved ones develop memory disorders, and after reading Oliver Sacks’ The Man Who Mistook his Wife for a Hat as a teenager, her fascination with memory really took off.
“Episodic memory is so fascinating to me because your experiences and memories shape and define you as an individual,” says Tran of Stanford University, who is chairing a symposium on VR and memory at the CNS meeting. “What happens when you forget and lose those experiences?”
Tran will be presenting new, pre-press work, led by Hadi Hosseini (Stanford), that shows how VR-based memory assessments can be used in combination with biofluid biomarkers of Alzheimer’s to predict who might be at risk of developing the disease. Working with young adults, clinically unimpaired older adults, and patients with mild cognitive impairment (often a precursor to Alzheimer’s), her team asked participants to remember the location of different objects, such as a TV remote or glasses, within a VR living room. They were also asked to recreate the living room environment in a later task.
“We found decreased object location memory, as well as decreased precision for the object location memory, between young adults and older adults and unimpaired participants and those with mild cognitive impairment,” she says.
To better contextualize these assessments, they worked with neurologists to collect Alzheimer’s disease biofluid biomarkers, specifically plasma Aβ42/Aβ40 and pTau217 from the older adult participants. “We found that pTau217 predicted both object location memory and location precision performance across our sample,” Tran says. “These findings indicate that across both clinically unimpaired older adults and patients with mild cognitive impairment, presence of Alzheimer’s proteins significantly impacts memory performance.”
This work is consistent with an emerging research that indicates that the presence of Alzheimer’s proteins impact memory function in subtle but detectable ways before the onset of clinical symptoms. Linking these Alzheimer’s disease biomarkers to cognitive function using immersive VR is something that would have been unimaginable even 5 years ago, Tran says. That’s because of research made possible by NIH funding, as well as the work of advocacy of organizations like the Alzheimer’s Association, that has transformed diagnosis of the disease – moving from post-mortem biomarker analysis, to imaging, and then cerebrospinal fluid, biomarkers, to collecting proteins from blood plasma.
The work is also exciting in how it has transformed an entertainment technology for clinical uses. “I’ve been working in the Alzheimer’s field for about 10 years, and I have never seen such excitement from participants when they’re doing an experiment,” Tran says. “For many people, this is their first experience with immersive virtual reality but since the movement is meant to mimic real-life, it is remarkably easy for them to pick up an item, walk around the room, and interact with the virtual world.”
The innovative use of VR technology in cognitive neuroscience is what attracted Manu Madhav to the research. An engineer and roboticist by training, he was fascinated by the parallels between the way robots process and integrate sensory information, and the way human brains evolved to do the same. After working on spatial navigation in rodents, he had the opportunity to collaborate with a center for Alzheimer’s disease to develop VR methods for measuring spatial navigation impairments in Alzheimer’s patients.
“Engineering VR to be comfortable and intuitive for older participants has been the greatest challenge,” he says. “We managed to find small but significant improvements that nevertheless have made it possible to place older participants in an immersive VR environment for over an hour with minimal concerns of nausea or disorientation.” These VR systems integrate sensors for head and eye tracking, as well as controllers that can allow for rich and expressive input.
Madhav’s team’s work is now in the early phase, working with healthy older adults and young adults but has already shown promise. They asked participants to navigate a series of corridors in a VR space while keeping track of their starting location and the locations of periodically hidden landmarks.
“We have found that healthy younger and older adults differ in their navigational abilities, setting the stage for our recruitment of participants with early Alzheimer’s disease scheduled to begin this year,” he explains. “We expect that the presence of different complexity levels across trials will amplify differences between younger and older participants, and between older participants and those diagnosed with early Alzheimer’s disease.”
Madhav sees VR as an exciting tool not only for understanding and diagnosing Alzheimer’s disease but also for exploring other cognitive questions and disorders. “The recent, unprecedented increase in accessibility to VR systems should allow for cognitive neuroscience labs with comparatively less expertise to jump into the space and leverage VR to answer complex cognitive questions that require immersion and multimodal feedback.”
This article was originally published on news-medical