When was the last time you found a café you didn’t know by looking at street signs, referencing nearby shops, or simply asking a stranger? Your answer to this question is likely “almost never.”
Our sense of direction has shrunk to a single pixel: a pulsing “blue dot” in the middle of the screen that shows us where to go. We no longer look at the trees around us, the bakery on the corner, or even the position of the sun. We simply wait for the dot to guide us, without straining our minds.
The Journey Stuck On The Screen
But is there a price for this convenience? Is it just a coincidence that we feel afraid when our phone battery dies? In contrast, the Inuit people of the Arctic could navigate even the most severe storms by reading the stars and wind tracks (O’Connor, 2019). This skill was enough to keep them alive for thousands of years.
Science delivers a harsh warning that this isn’t just a loss of skill; we may be facing a situation that causes a physical change deep within our brain.
The Mappers Inside
How do we know where we are? Most importantly, how do we store that information so it comes to our mind immediately when needed? Two studies sharing the 2014 Nobel Prize in Medicine give us the answer.
First, let’s consider place cells discovered by neuroscientist John O’Keefe in the hippocampus, the memory center of our brain. Imagine a map with pins marking specific locations; you can think of these nerve cells like these pins. According to experiments, when a subject stops at a certain point, only special nerve cells tuned to that specific location fire (O’Keefe & Dostrovsky, 1971). These cells use visual cues and record the information of where we are.
Secondly, let’s consider grid cells. Residing in the entorhinal cortex, which plays a key role in memory formation, these nerve cells discovered in May-Britt and Edvard Moser’s laboratory function like a coordinate system. They do not fire for a single spot but at regular intervals in a hexagonal pattern, weaving a virtual net on the ground as we move. This allows the brain to calculate the direction and the distance (Hafting et al., 2005).
In short, place cells indicate position by saying, “We are in the living room,” while grid cells specify distance and coordinates as we move from the kitchen to the living room by saying, “We have moved 5 meters to the left.” Together they form our internal GPS and support spatial navigation.
Use It Or Lose It
For most of our history, we used to think that the brain was an unchanging structure. Science now shows that the brain has an ability called neuroplasticity, the ability to physically change and reorganize its connections based on environmental factors (Maguire et al., 2000). Neuroplasticity is governed by the “Use It or Lose It” principle. Simply put, our cognitive abilities and their neural circuits must remain active to survive.
A striking example showing that our brain’s spatial memory tends to strengthen with use comes from London streets. Eleanor Maguire and her team studied the brains of the London taxi drivers, who must memorize about 25,000 streets in the city to earn their license, and found that they had a larger volume in the back of their hippocampus compared to the general population. Moreover, as the driver’s experience grew, the difference increased (Maguire et al., 2000). This adaptation was not restricted to physical changes only; these drivers showed higher success rates in spatial memory tests compared to bus drivers who followed fixed routes (Maguire et al., 2006).
However, just as a muscle “melts” without exercise, spatial memory weakens when unused. In her study, Véronique D. Bohbot showed that our navigation strategies affect the physical structure of our brain; lower tissue density was found in the hippocampus of individuals who tend to navigate by rote memory, memorizing turns blindly, rather than using a spatial map (Bohbot et al., 2007). Research also shows that regular GPS use leads to a decline in spatial memory, and this effect depends on how often we use GPS—in other words, the dose (Dahmani & Bohbot, 2020).
The Silent Threat
There is a factor that makes the situation even more dire. Research suggests that Alzheimer’s disease (AD) often attacks the spatial navigation network, our inner GPS, before any issues with personal memories begin. This critical navigation network, which includes the entorhinal cortex and hippocampus, is highly susceptible to AD. Spatial navigation deficits could be an overlooked cognitive marker even for earlier stages of AD, before symptoms appear (Coughlan et al., 2018). In light of this evidence, by over-relying on technology for finding our way, we may be weakening our most vulnerable areas with our own hands.
Conclusion: Reclaiming Our Map
Every time we reach for our phones, we dull this magnificent evolutionary navigation system a little more. This technology, which pacifies our spatial navigation network, detaches us from our surroundings. As the taxi drivers proved, our brains evolve with use; however, when we completely abandon ourselves to the comforts of technology, we may be tearing down the walls of this vulnerable area.
For this very reason, perhaps we should sometimes dare to get lost, leave our phones in our pockets, and try to find the café we want by looking around. Perhaps this may be the best training to keep our minds sharp.
References
Bohbot, V. D., Lerch, J., Thorndycraft, B., Iaria, G., & Zijdenbos, A. P. (2007). Gray Matter Differences Correlate with Spontaneous Strategies in a Human Virtual Navigation Task. Journal of Neuroscience, 27(38), 10078–10083. https://doi.org/10.1523/jneurosci.1763-07.2007
Coughlan, G., Laczó, J., Hort, J., Minihane, A., & Hornberger, M. (2018). Spatial navigation deficits — overlooked cognitive marker for preclinical Alzheimer disease? Nature Reviews Neurology, 14(8), 496–506. https://doi.org/10.1038/s41582-018-0031-x
Dahmani, L., & Bohbot, V. D. (2020). Habitual use of GPS negatively impacts spatial memory during self-guided navigation. Scientific Reports, 10(1), 6310. https://doi.org/10.1038/s41598-020-62877-0
Hafting, T., Fyhn, M., Molden, S., Moser, M., & Moser, E. I. (2005). Microstructure of a spatial map in the entorhinal cortex. Nature, 436(7052), 801–806. https://doi.org/10.1038/nature03721
Maguire, E. A., Gadian, D. G., Johnsrude, I. S., Good, C. D., Ashburner, J., Frackowiak, R. S. J., & Frith, C. D. (2000). Navigation-related structural change in the hippocampi of taxi drivers. Proceedings of the National Academy of Sciences, 97(8), 4398–4403. https://doi.org/10.1073/pnas.070039597
Maguire, E. A., Woollett, K., & Spiers, H. J. (2006). London taxi drivers and bus drivers: A structural MRI and neuropsychological analysis. Hippocampus, 16(12), 1091–1101. https://doi.org/10.1002/hipo.20233
O’Connor, M. R. (2019). Wayfinding. Hachette UK.
O’Keefe, J., & Dostrovsky, J. (1971). The hippocampus as a spatial map. Preliminary evidence from unit activity in the freely-moving rat. Brain Research, 34(1), 171–175. https://doi.org/10.1016/0006-8993(71)90358-1