Brain-cell glitches might explain why older people tend to get lost more easily.
The brain’s navigation centre includes neurons called grid cells, which fire in patterns that generate an internal coordinate system similar to the grid on a paper map. To investigate the effect of age on grid cells, Matthias Stangl at the German Center for Neurodegenerative Disease in Magdeburg and his colleagues recruited people aged 19 to 30 and others aged 63 to 81 to navigate both virtual and real environments. The researchers monitored the participants’ grid cells using a technique called functional magnetic resonance imaging (fMRI).
Older participants fared worse than younger individuals on a path-navigation test. Reduced performance was associated with specific fMRI signatures that suggested that in older individuals, the grid cells’ firing is altered. This change probably reduces the reliability of the brain’s internal coordinate system.