Weaker navigation signals may reflect instability in older adults
An observational study using virtual navigation and brain scans in 85 older adults linked steadier directional activity patterns to stronger signals.
Limit: Brain scans measured a proposed marker of grid-cell activity, not grid cells themselves
Edited by Boris Djordjevic · AgingResearch.News
In an observational study, 85 older adults navigated a virtual environment while researchers measured their brain activity with scans that track blood flow. They examined a six-direction activity pattern thought to reflect grid cells, brain cells thought to support navigation and memory.
The researchers compared this signal’s strength with how consistently its directional pattern recurred across scanning runs. More stable patterns were associated with stronger signals in the posterior-medial entorhinal cortex, a brain region. On its left side, greater stability was also associated with better memory for object locations. Age and local brain structure did not account for individual differences in signal strength or stability. The authors suggested that weaker signals may reflect unstable grid-cell-like representations rather than their absence.
Why it matters
Navigation and memory for events decline with age. This work bears on how the brain represents space and how those representations relate to memory differences among older adults.
Caveats
The scans measured a proposed marker of grid-cell activity, not grid cells themselves, and the observational design cannot establish cause and effect. The study included only older adults and is a preprint that has not been peer-reviewed.
- Hexadirectional orientation stability
- Hexadirectional signal strength
- Local structural measures
- Object location memory
- Retrosplenial absolute-orientation stability
- Humans
The paper
Temporal instability weakens entorhinal grid-like coding in older adults
Dzne
bioRxiv, Oct 21, 2026, Open access, CC BY, Preprint, not peer-reviewed
