Navigation and the “inner GPS”


Navigation is the most elemental of our skills — “Where am I?” was the first question a creature had to answer — and it’s the one that gives us our tightest connection to the world. The loss of navigational sense is also often the first sign of a mind in decay. Last week, the Nobel Committee announced that this year’s Nobel Prize in Physiology and Medicine will go to three scientists — John O’Keefe and the couple May-Britt and Edvard Moser — whose work has revealed the intricate biological underpinnings of our talent for getting around. O’Keefe discovered the brain’s place cells, which map out particular places, and the Mosers discovered the brain’s grid cells, which give us a general sense of spatial reckoning.

Here’s how I sum up the work of O’Keefe and the Mosers in the “World and Screen” chapter of The Glass Cage:

In a landmark study conducted at University College London in the early 1970s, John O’Keefe and Jonathan Dostrovsky monitored the brains of lab rats as the rodents moved about an enclosed area. As a rat became familiar with the space, individual neurons in its hippocampus—a part of the brain that plays a central role in memory formation—would begin to fire every time the animal passed a certain spot. These location-keyed neurons, which the scientists dubbed “place cells” and which have since been found in the brains of other mammals, including humans, can be thought of as the signposts the brain uses to mark out a territory. Every time you enter a new place, whether a city square or the kitchen of a neighbor’s house, the area is quickly mapped out with place cells. The cells, as O’Keefe has explained, appear to be activated by a variety of sensory signals, including visual, auditory, and tactile cues, “each of which can be perceived when the animal is in a particular part of the environment.”

More recently, in 2005, a team of Norwegian neuroscientists, led by the couple Edvard and May-Britt Moser, discovered a different set of neurons involved in charting, measuring, and navigating space, which they named “grid cells.” Located in the entorhinal cortex, a region closely related to the hippocampus, the cells create in the brain a precise geographic grid of space, consisting of an array of regularly spaced, equilateral triangles. The Mosers compared the grid to a sheet of graph paper in the mind, on which an animal’s location is traced as it moves about. Whereas place cells map out specific locations, grid cells provide a more abstract map of space that remains the same wherever an animal goes, providing an inner sense of dead reckoning. (Grid cells have been found in the brains of several mammal species; recent experiments with brain-implanted electrodes indicate that humans have them too.) Working in tandem, and drawing on signals from other neurons that monitor bodily direction and motion, place and grid cells act, in the words of the science writer James Gorman, “as a kind of built-in navigation system that is at the very heart of how animals know where they are, where they are going and where they have been.”

If “Where am I?” is the first question a creature had to answer, that suggests something else about us, something very important: memory and navigational sense may, at their source, be one and the same. The first things an animal had to remember were locational: Where’s my home? Where’s that source of food? Where are those predators? So memory may have emerged to aid in navigation. That’s something that both O’Keefe and the Mosers have thought about, and that Edvard Moser has begun to explore scientifically:

In addition to their role in navigation, the specialized cells appear to be involved more generally in the formation of memories, particularly memories of events and experiences. In fact, O’Keefe and the Mosers, as well as other scientists, have begun to theorize that the “mental travel” of memory is governed by the same brain systems that enable us to get around in the world. In a 2013 article in Nature Neuroscience, Edvard Moser and his colleague György Buzsáki provided extensive experimental evidence that “the neuronal mechanisms that evolved to define the spatial relationship among landmarks can also serve to embody associations among objects, events and other types of factual information.” Out of such associations we weave the memories of our lives. It may well be that the brain’s navigational sense — its ancient, intricate way of plotting and recording movement through space — is the evolutionary font of all memory.

That would certainly help explain why early memory loss in dementia often manifests itself in a loss of navigational sense.

It was revealing that, when journalists reported on the Nobel last week, they often summed up the scientists’ breakthroughs as involving the discovery of “the brain’s GPS” or our “inner GPS.” That’s a great example of how we often draw on recent technologies as metaphors for the workings of our bodies and minds. Of course, our brains are not receiving signals from satellites (at least not yet); they’re receiving a rich mix of sensory signals about the physical world. The danger in the metaphor is that, in implying a fundamental similarity between an external navigation system and an internal one, it also suggests that which system we use doesn’t matter. Either will get you where you want to go. Lost in the metaphor is the elemental quality of our navigational skill — its importance in connecting us to the world, in giving us a sense of place, and its possible importance to the healthy working of memory. One thing the work of O’Keefe and the Mosers tells us is that the ability to answer the question “Where am I?” through one’s own resources may not be as dispensable a skill as we assume.

7 thoughts on “Navigation and the “inner GPS”

  1. Andrew Francis

    Reading this post reminded me of a book I borrowed a few years ago: Frances Yate’s The Art of Memory (unfortunately I didn’t finish it). The Art of Memory discussed a concept called “memory palaces” (method loci). A key trick was to associate facts with places in an intimately known space (i.e., a house). For various reasons, memory palaces had fallen out of favour by the Renaissance.

    There is an interesting 2012 TED talk by Joshua Foer on the subject. Foer’s talk covers many of the same themes concerning what outsourcing cognitive facilities to one’s mind.

    I decided to google John O’Keeefe and memory palaces. I turned up the New York Times article “A Sense of Where You Are.” An excerpt:

    On the most profound level, Dr. O’Keefe, the Mosers and others speculate that the way the brain records and remembers movement in space may be the basis of all memory. This idea resonates with the memory palaces of the Renaissance, imagined buildings that used spatial cues as memory aids. The technique dates to the ancient Greeks. In this regard, neuroscience may be catching up with intuition.

  2. Nick Post author

    Yes, I don’t think it’s a coincidence that the most powerful mnemonic technique involves setting things in an imaginary place and then having the mind walk through the place.

  3. Andy F

    Of course, our brains are not receiving signals from satellites (at least not yet)

    I find it fascinating to imagine how life would will change once brain-implantable GPS becomes a reality.

  4. Brutus

    Fascinating stuff here. Use of language metaphors comes quite naturally to us, but the misapplication of technology metaphors (e.g., the brain is a computer) is a subtle tell (according to some critics) that we desire to merge with and ultimately become the machines we so admire. It’s the Transhumanist fever dream. But the loss of self incurred when we outsource cognition to devices is only now beginning to become apparent. Up to a point, we are more powerful and engaged, but after a point (good luck placing it with any precision), we face severely diminished returns.

  5. Henry Beer

    “…setting things in an imaginary place and then having the mind walk through the place” is of course what architects do for a living. The difference between truly great architects and the fashion-obsessed ones is how their minds process that experience. Are they looking for elements that will trigger certain positive emotional and navigational responses in the building’s users or are they simply looking for aspects that will be perceived as “cool” by their architectural fashionista colleagues?

    On another point related to tech metaphors… GPS is a remarkable metaphor
    for how best to gather data and form an opinion. The accuracy of one’s position is greatly enhanced by acquiring as many satellites as possible. One also wants those satellites to be as far from each other as possible. If the satellites are other opinions or positions on a subject and if they are significantly diverse, there’s an excellent chance one will avoid confirmation bias and arrive at a well-considered “position.”

  6. XSA

    “Combining elements of both satire and maps, satirical maps are meant to inform, entertain, and shock all at once. Like much satire, satirical maps take something familiar and make it unfamiliar, by imbuing a sense of incongruity that is often unexpected by audiences. In many cases, satirical maps appropriate the outline of a political unit, which is a familiar image to most audiences, such as the geographical shape of a nation, to create a cartoon stereotype of its people and/or a caricature of its political situation.”

    Surreal art not art. This is how the Cold War was won. Crimea not Crimea, so now it is Russia and everybody is getting lost instead of getting gassed by Russians. “Satirical maps first became popular in the nineteenth century, as satirical illustrations found wider distribution in newspapers and satirists recognised the growing interest in maps as (geo)political tools and the power that combining satire and cartography”…so don’t just tell them to get lost show them. I’m still using trusty nineteenth century technology. New Russian maps goal is the same as old German goals. The new satellites ended up in the wrong orbit. Our compass is constantly spinning.

    A Simple Plumbing Problem Sent Galileo Satellites Into Wrong Orbits
    IEEE Spectrum · 10 hours ago

    One of the reasons is that the two satellites, stranded in wrong orbits, can still earn back the expense of 150 … or we have information that something has… Russian flaw behind botched satnav satellite launch: Arianespace

    With the Russian plumbing problem, pipes may need torn out. They put the toilet in the kitchen?

  7. XSA

    ““You’re flying blind, knowing there’s mountains all around you.” Alone in a nimble Cessna, Eule was able to turn around. Stack and Beane, in a larger plane carrying most of the 1,000-pound moose, were forced to press on, eyes glued to a handheld GPS screen, praying its fusion of satellite signals and government terrain maps would guide them to safety.

    Unfortunately, the maps were wrong.

    Alaska, it turns out, has never been mapped to modern standards.”

    $150 million will save billions of dollars. “For about $150 million a year, the USGS estimates the new maps could boost government savings and private investment by as much as $13 billion annually.” It’s a no-brainer!

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