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The Hippocampus as a Cognitive Map


What is a map? A map is a symbolic representation of some spatial region. It is usually drawn on some flat surface but not in all cases as globes are maps and there are relief maps and 3D maps and now computer maps. Map making is very old, the map on the left is a Babylonian map of the world from 300 to 500 BC and one of the oldest surviving maps (7). References to maps go back thousands of years and maps from indigenous peoples, sometimes drawn in the sand or on snow, show that map-making is an ancient human skill (8). Maps usually encompass local regions bounded by mountains, a river, a lake or ocean, or islands in an ocean. As civilizations got larger, maps started to encompass the whole world. Recently, the first 3D map of the Universe was created. Distance is measured in space-time, objects further away are also further back in time (9). Is this a special skill of only humans? Every creature must move around in their world and some migrate tens of thousands of miles each year. Bees dance out locations of flowers to their hive mates. Rats solve mazes. Many creatures mark territory and safe passageway. Not only navigation but communication of places to others is a part of nature. Humans have just taken this to another level.


The 2014 Nobel Prize in Medicine was shared by three people, John O'Keefe at University College London, United Kingdom, and the husband and wife team of Edvard L. Moser and May-Britt Moser at The Centre for Neural Computation and Kavli Institute for Systems Neuroscience; Norwegian University of Science and Technology, Norway. That year's prize was for the theoretical foundations and subsequent discovery of the cellular neural structure of the hippocampus, the so-called cognitive map (5).


Cognitive maps were first mentioned in the literature by EC Tolman in 1948, although he didn't locate it in the hippocampus. John O'Keefe, in 1971, after studying the literature on amnesia patients and doing his own experiments on rats came up with the idea of a cognitive map residing in the hippocampus. He, with Lynn Nadel, wrote a book called The Hippocampus as a Cognitive Map (1) which took 6 years to write. In addition to the theory the book contains many important contributions:


  • How humans navigate.

  • How animals navigate, migration in birds.

  • A long philosophical digression into the theories of physical and psychological space.

  • A critical look at behaviorist theory.

  • What would now be called a meta-analysis of all the behavioral and neurological experimental literature to date including animals of different species and amnesia studies in humans.


The idea of space has always had two components, physical space, the underlying structure of reality, and psychological space, how humans perceive space in the mind. In addition to two types of space, there are two theories of space, relative and absolute. Absolute space argues that space is a thing in itself, Objects move and exist only in terms of a fixed reference point in absolute space. This is the criteria of Newton's Laws. Newtonian physics assumes an absolute space to measure off of. In stark contrast, Leibnitz postulated a purely relational space (4). Reality consists of entities called Monads in which each individual monad is perceptually connected to the other. Space is a purely relational structure consisting of these Monads. In this system, the idea of an absolute space doesn't exist.


"Now this connexion or adaptation of all created things to each and of each to all, means that each simple substance has relations which express all the others, and, consequently, that it is a perpetual living mirror of the universe"

The Monadology 56, 1714


One thing both agreed on was that psychological space was purely relational.


In 1905 Einstein published his Theory of Special Relativity. One of his accomplishments was that it was a purely relational theory of space that held Newton's laws as a particular case. Then, in 1915 he published his Theory of General Relativity which added a geometric theory of gravity. It is thought that absolute space no longer exists in physics but this is not true. General Relativity introduced a new fixed reference point, that of acceleration instead of velocity. In 2000 a group of physicists postulated what was called the Dynamical Approach (DA) which used the dynamic laws and their underlying symmetries as reality. Space and time are just figments derived from these symmetries, not real. This is considered a relational theory of space (2). Recently the theoretical physicist Lee Smolin returned to Leibnitz and the Monads. In it, he saw both entanglement (“connexion”) and fields (“relations which express all others”) (3). Both DA and Smolin's views are speculative and at this point in time purely relational physical space is something that has not been fully achieved.


Psychological space throughout history has been considered relational and Piaget's theories of early learning assumed a purely relational space in which a child used to construct the world. The problem with Piaget was how a child builds reality from nothing and how these relational spaces get connected to provide a whole concept of the world. One important exception to these arguments was Emmanuel Kant. In Critique of Pure Reason in 1781, Kant wrote this as a direct challenge to Leibnitz and in support of Newton. Psychological space is absolute, Euclidean, and intuitive, and an inherent product of the mind. (9)


"a fixed law of the mind, in virtue of which it is necessary that all the things that can be objects of the senses . . . are seen as necessarily belonging to the same whole."

The Critique of Pure Reason, 1781


“Space is not a discursive or, as is said, general concept of relations of things in general, but a pure intuition. For, first, one can only represent a single space, and if one speaks of many spaces, one understands by that only parts of one and the same unique space.”

The Critique of Pure Reason, 1781


O'Keefe and Nadel concede that perceptions are built up relationally. In addition, the creation of local maps is a relational process. In addition, they proposed another structure, a cognitive map that represents space in an absolute sense. This map is intrinsically Euclidean, some set of geometric rules are part of its structure from birth. This solves both of the problems with Piaget's purely relational learning. Thirty-eight years later with the formal description of the main cell types, O'Keefe wins the Nobel Prize in Medicine.


All this leads me to question the use of mapping technology and how it may degrade human thought. Routing programs don't serve as much as guides as they don't use landmarks but reduce directions to distance and left and right turns. Driverless technology will further reduce everyone to passive riders. A famous paper in 2000 (10) shows that London cab drivers had a larger hippocampus than average. In addition, size increased with

years of experience. Will this new reliance on automated routing reduce our abilities to learn and memorize? Learning and memory are directly tied to this hippocampal spatial system. Spatial knowledge is important and needs to be taught at an early age.


  1. O’Keefe, John, and Lynn Nadel. The Hippocampus as a Cognitive Map. Oxford : New York: Clarendon Press ; Oxford University Press, 1978.

  2. Huggett, Nick, and Carl Hoefer. “Absolute and Relational Theories of Space and Motion.” In The Stanford Encyclopedia of Philosophy, edited by Edward N. Zalta, Spring 2018. Metaphysics Research Lab, Stanford University, 2018. https://plato.stanford.edu/archives/spr2018/entries/spacetime-theories/.

  3. Amanda Gefter. “How to Understand the Universe When You’re Stuck Inside of It.” Quanta Magazine. Accessed April 11, 2020. https://www.quantamagazine.org/were-stuck-inside-the-universe-lee-smolin-has-an-idea-for-how-to-study-it-anyway-20190627/.

  4. Davis, Jessica. “The Monadology (1714), by Gottfried Wilhelm Leibniz (1646-1716),” n.d., 15.

  5. O’Keefe, John. “Spatial Cells in the Hippocampal Formation - Nobel Lecture,” December 7, 2014.

  6. Museum, Trustees O. T. B. "Babylonian Map of the World." Ancient History Encyclopedia. Last modified April 26, 2012. https://www.ancient.eu/image/526/.

  7. Hutorowicz, H. de, and B. F. Adler. “Maps of Primitive Peoples.” Bulletin of the American Geographical Society 43, no. 9 (1911): 669–79. https://doi.org/10.2307/199915.

  8. “Biggest 3D Map of the Universe yet | EarthSky.Org.” Accessed May 3, 2020. https://earthsky.org/space/biggest-3-d-map-universe-sdss-sloan.

  9. Kant, Immanuel, Paul Guyer, Allen W. Wood, and Immanuel Kant. Critique of Pure Reason. The Cambridge Edition of the Works of Immanuel Kant. Cambridge ; New York: Cambridge University Press, 1998.

  10. Maguire et al.“Navigation-Related Structural Change in the Hippocampi of Taxi Drivers | PNAS.” Accessed May 9, 2020. https://www.pnas.org/content/97/8/4398.



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