Egocentric Spatial Memory Deficit in Amnestic Mild Cognitive Impairment Revealed Through Virtual Reality: a Cross-Sectional Study
ABSTRACT
Background:
Spatial navigation relies on egocentric (body-centered) and allocentric (environment-centered) frames of reference, with the latter critically impaired in Alzheimer’s disease (AD) due to hippocampal involvement. However, recent studies suggest egocentric representations may coexist within medial temporal lobe regions, yet their relative impairment in the early phases of AD remains unclear. Crucially, innovative technologies could overcome such a gap by assessing spatial navigation abilities and providing sensitive digital biomarkers for AD.
Objective:
This study investigated spatial memory performance in amnestic mild cognitive impairment (aMCI) using a virtual reality object-location memory task that distinguishes between egocentric (landmark-based) and allocentric (boundary-based) frames of reference.
Methods:
Eighty participants (40 aMCI and 40 healthy controls; HC) encoded object locations in a virtual arena and recalled them using either landmark or boundary cues.
Results:
aMCI demonstrated significantly poorer overall spatial memory compared to the HC group, with virtual egocentric error emerging as a predictor of aMCI diagnosis. No frame-switching, object-location binding, and testing trials differences were observed. Analysis of virtual encoding paths revealed that aMCI exhibited centrifugal navigation away from the landmark and toward the boundary, while HC showed the opposite pattern. At recall, aMCI demonstrated less effective utilization of boundary and landmark cues than HC as revealed by response point patterns.
Conclusions:
These findings suggest that in addition to the prevalent focus on allocentric deficits in aMCI, egocentric spatial memory impairments provide a complementary and potentially sensitive digital biomarker in AD. This dual impairment of spatial cognition systems revealed by virtual behavior enhances our understanding of navigational difficulties in aMCI and offers insight into the nature of representations of the space in aging. Clinical Trial: NA
Citation
Request queued. Please wait while the file is being generated. It may take some time.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.