Scientists have finally figured out why grandma and grandpa always get lost. It’s because certain neurons known as grid cells, which are crucial for spatial navigation, strangely seem to retire with age, according to a new study.
“No one has so far investigated whether grid cell function changes with old age, and whether this might explain age-related navigational deficit,” coauthor on the study Matthias Stangl, of the the German Center for Neurodegenerative Disease, told Fatherly.
Grid cells are neurons located in the entorhinal cortex, the part of the brain that handles memory and navigation. They play a key role in a person’s ability to mentally map their locations, research shows. And some studies posited that Alzheimer’s patients tend to experience more problems with navigation due to grid cell degeneration. But until now, there was no established link between grid cell degeneration, getting lost, and simply getting older.
For this new study, Stangl and his colleagues worked with a small sample of 20 younger participants (between the of ages 19 and 30) and 21 older people (between the ages of 63 and 81). For the first experiment, participants had to complete a navigation test in virtual reality while hooked up to fMRI brain scanners. In the second experiment, participants completed additional navigation tasks in virtual reality and in the real world. As expected, young people performed better on navigation tasks overall. Less expected was that grid cell firing patterns became less stable with age—and this lack of neural stability was directly associated with lower performance in navigation tasks.
The intent of the research was to establish a direct connection between grid cells and decreased navigation abilities and spatial orientation with age—as a bedrock for future studies—so the practical takeaways are limited. But Stangl says the next step may be looking at protective factors that can prevent grid cell degradation and other neurological problems. “It is important to focus on protective factors that can help to reduce or even prevent cognitive decline in old age,” he says.
Now all they have to do is find grandma.