The Hippocampus & Action at a Distance
Seahorse, from the series Fishers and Fish (N74) for Duke brand cigarettes, Knapp & Company playing cars, W Duke Sons & Co 1888
Maybe memory is a way we communicate with ourselves and the world at various layers, our ‘bridging experience’ of time and space.
In this episode, Andrea Hiott and Lynn Nadel continue their ongoing talks about memory. This time they explore the intricate workings of the hippocampus, focusing on its role in bridging spatial and temporal gaps. They delve into how memory, navigation, and cognitive maps are interconnected, challenging traditional views and opening up discussions on the dynamic nature of memory.
Lynn shares insights from his paper on memory and action at a distance, discusses how past research has evolved, touching upon philosophical perspectives from Kant and modern neuroscience findings. The conversation also moves into broader implications, including how understanding the hippocampus might extend to a wider view on cognitive functions and societal interactions.
There’s an in-depth ‘research ramble’ from Andrea at the beginning for those interested in the wider themes of this whole project, but you can also skip that and go to the main conversation at 43:43 if you wish.
This is a bonus episode. Our next episode for the holidays is on Michael Polanyi with Esther Lightcap Meek, focusing on her book Loving to Know, so keep a look out for that one soon, too.
Find the audio on your platform
The main paper discussed here is The Hippocampal Formation and Action at a Distance
Lynn Nadel is an American psychologist who is the emeritas Regents’ Professor of psychology at the University of Arizona. Nadel specializes in memory, and has investigated the role of the hippocampus in memory formation. Together with John O’Keefe, he coauthored the influential 1978 book The Hippocampus as a Cognitive Map.
00:00 Introduction to Hippocampal Function
02:07 The Role of Memory and Space
11:38 Philosophical Insights on Space and Time
15:50 Quantum Entanglement and Memory
28:48 Hippocampus as a Cognitive Map
43:43 Encouragement and Introduction to Lynn Nadel
44:30 Discussing the Paper: The Hippocampal Formation and Action at a Distance
44:55 Linking Time and Space: The Role of the Hippocampus
47:21 Memory and Cognitive Maps
49:59 The Evolution of Cognitive Map Theory
51:34 Intertwining Memory and Navigation
01:04:30 Philosophical Perspectives on Space and Time
01:09:37 Innate Structures and Evolutionary Adaptations
01:16:08 Plant Cognition and Tropisms
01:16:59 The Importance of Memory
01:17:39 Cognitive Maps in Animals
01:17:57 Symposium and Research Updates
01:19:08 Locomotion and Cognitive Needs
01:20:54 Internal Models and Memory
01:23:27 Temporal Contiguity vs. Contingency
01:29:26 Dynamics of Memory
01:35:11 Concluding Thoughts and Future Plans
01:36:34 Hippocampus and Social Interactions
*This full post with all its quotes, especially the list from Lynn’s writings at the end, is too long for email, so please click and read on the website or App if you would like to see the full text*
Previous conversations with Lynn and Andrea
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Paper: The Hippocampal Formation and Action at a Distance
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Introduction (A cleaned up version of Andrea’s improv audio Intro)
How does the brain allow us to transcend the here and now? What is the relation between space and memory? How are all these connected? Perhaps memory is a word we use to describe our awareness of the habits that bind us with the action we encounter—not just storage, but a mechanism that liberates us from being bound to the immediate present, both through remembering the past and imagining the future through that same habituation with different degrees of awareness and conversation with ourselves. In other words, as Andrea puts it in the intro, maybe memory is the communication we are having with ourselves by way of our relation with the world as we encounter it.
“Perhaps memory is our communication with ourselves, and we experience it as thinking and action at different times and towards different goals.” (A.H.)
This connects to constellation cognition and the metaphor of the kaleidoscope, because we experience ourselves and others as “constellations rather than either/or formulations”.
As Gregory Bateson said, it takes two to know one—which means everything is always a communication of at least three different positions simultaneously, whether that’s past, present, future, or body, brain, world. Andrea: ‘these are the triads of stability we experience in the layers of our constellatory connection.’
Imagine two particles that have interacted, becoming so deeply connected that measuring one instantly affects the other, no matter how far apart they travel across the universe. This phenomenon, called quantum entanglement, defies our everyday intuition about how objects should behave when separated by vast distances. Einstein famously called it “spooky action at a distance” because it seemed to suggest that information or influence could somehow leap across space faster than light should allow. When we measure a property like spin on one entangled particle, its partner immediately “knows” and takes on a corresponding state, even if it’s on the other side of the galaxy. This does not happen due to signals traveling between them; rather, particles are somehow sharing a quantum state so fundamentally that they can’t be described independently, as if distance itself is somehow not there or meaningless from some other position (obviously still mysterious to us and our ways of measuring all this).
Just as quantum entanglement creates mysterious connections between particles across space, memory—powered in large part by the hippocampus—might be imagined as an activity of connection across space & time that allows you to move between past and future and here and now. Your brain performs its own kind of action at a distance: you navigate to a coffee shop you can’t currently see, you avoid a danger you experienced weeks ago, you plan for events months away.
Without your hippocampus, you’d be trapped in what neuroscientist Lynn (quoting Corkin’s book on the famous patient H.M.) calls the “permanent present tense”—unable to bridge the gaps between where you are and where you want to be, between what happened then and what’s happening now and able to imagine something else happening.
Entanglement defies spatial separation while memory (or the action of remembering or imagining, which aren’t all that different for the brain) gives us the power to also defy spatiotemporal separation. Lynn says we do this by “stitching together spatiotemporally disparate entities and events.” Andrea sees it all as a much more immediate alignment, and much of this text is taken from her audio and writings.
Quantum entanglement is also unmediated, or ‘ecological’ in the way that term is used in some of the Gibsonian literature; it requires no intermediaries, and yet our experience of memory is itself (to us) the constant mediator of this seeming spectrum of spacetime. Both these ideas (entanglement and remembering/imagining) challenge our intuitive sense that things only affect each other when they’re geographically close or tangible.
Kantian foundations
To understand why this matters, we can step back into philosophy for a moment and talk about one of Lynn’s favorite philosophers, Immanuel Kant.
Immanuel Kant argued that space and time are not things existing independently “out there,” but rather are a priori forms of intuition—mental structures that our minds impose on raw experience before we can perceive anything at all (which Andrea argues is ecological or immediate bodily cognition rather than any sort of imposing).
Lynn Nadel explicitly invokes this in his work, writing that through hippocampal processes, “our subjective sense of both space and time are interwoven constructions of the mind, much as the philosopher Immanuel Kant postulated.”
Nadel and O’Keefe were already conceptualizing the hippocampus as a system for bridging spatiotemporal gaps, thinking of it as an innate Kantian absolute spatial framework not derived from experience, a flexible constellation-like system (in A’s terms) allowing navigation from any place to any other place, and a mechanism solving the identification problem by providing context for re-identification across different situations.
Today we can assess grid cells in the entorhinal cortex that “code a spatial structure that is generated internally within the brain and use it to scaffold the external environment, much in the same manner that Kant had anticipated.” Another way of thinking about this is to say that the hippocampus actively constructs space and time so as to organize all this ongoing experience.
getting more Hegelian
Quantum entanglement shows us that spatial separation isn’t absolute—particles can be fundamentally connected across distance in ways that defy classical locality. Kant argued our experience of space and time are mental constructions, not direct perceptions of reality as it is “in itself.” The hippocampus, as Nadel demonstrates, is the biological mechanism that stitches together spatiotemporally disparate experiences, creating our subjective sense of coherent space and time—it mediates “action at a distance” by bridging gaps. And Hegel, properly understood if you think Andrea’s way is proper (😅), showed that contradictions aren’t dead ends but generative, with truth emerging through dynamic interplay that we categorize but that is not absolutely categorizable.
All of these thinkers including Andrea and Lynn are grappling with the same fundamental mystery: how do we connect what is separated—whether particles across space, memories across time, or perspectives across minds? The answer seems to be: through structures that aren’t “out there” in objective reality, but rather emerge from relational, dynamic processes—whether quantum entanglement, hippocampal navigation, or constellation thinking.
the 1978 Book
In 1978, Lynn Nadel and John O’Keefe published “The Hippocampus as a Cognitive Map,” (which Andrea and Lynn have talked through often). Back then, they were already thinking about these issues towards the way we’re discussing them today whereby memory and navigation are ways of considering the same process. And this forms the foundation from which a lot can now grow, even if it asymmetrically.
As Lynn points out in the talk, the very first sentence of their introduction explicitly frames memory as central to their theory.
This book is concerned with three topics which, at first glance, do not appear to be related: (1) a part of the brain known as the hippocampus; (2) the psychological representation of space; (3) context-dependent memory. We shall argue that the hippocampus is the core of a neural memory system providing an objective spatial framework within which the items and events of an organism’s experience are located and interrelated.
They were already thinking of memory as a system for connecting disparate experiences across space and time.
action at a distance
Action at a distance refers to objects affecting each other across space or time without any apparent connection. Einstein famously called quantum entanglement “spooky action at a distance.”
But humans and animals perform their own version of action at a distance constantly. We navigate to goals we can’t see. We make decisions based on events from hours, days, or years ago. We plan for futures that don’t yet exist.
The hippocampus, Nadel argues, is the brain system that makes this possible. It does so through what we can assess as interconnected mechanisms:
1. Creating cognitive maps that represent extended spatial contexts—linking places you’ve never experienced together into a coherent model
2. Building neural trajectories that connect events across time, even when those events are separated by significant gaps
(Andrea then understands these as way-making and allows that when we are discussing memory or when we are discussing navigation, we are still able to do the following, which she calls Navigability:
3. Use these maps and trajectories to simulate possible futures)
Without a hippocampus, we’re stuck with what’s immediate, which is not as great as it might sound because we have no trajectory to which to compare it. As Andrea says, we ‘lose our connection to the tacit’ and this might be the real clue to what the hippocampal formation has to show us about relation.
superstitious brains
Animals with hippocampal damage become locked to (or trapped in) temporal contiguity alone and are highly superstitious—they can only connect events that happen immediately together, missing the deeper patterns of contingency that govern how the world actually works. They become context-blind, unable to use the when and where of experience to distinguish what truly matters.
In a 1980 study, researchers Devenport and Holloway found that rats with hippocampal lesions become, in effect, highly superstitious. These rats could only connect events that happened in close temporal proximity—if A was followed immediately by B, they assumed A caused B. Further research found links to this and delusional thinking.
Understanding the world requires more than temporal contiguity. It requires contingency—the ability to track whether events reliably go together across many instances, separated by time and space. Does A really cause B, or do they just sometimes happen to occur together? These sorts of layers and real time alignements are hard for us to explain without reverting to linear causality, but the hippocampus is doing something more like entanglement, and at more than just one layer or scale.
Photo by Donald Wu on Unsplash
more specific to this discussion
Lynn and Andrea recorded this Action at a Distance conversation some months ago, which was approximately 50 years after Nadel and John O’Keefe first proposed their cognitive map theory, they explore these ideas and their implications for how we understand consciousness, memory, and our place in time and space. In it, they discuss how memory and spatial navigation aren’t separate functions but are deeply intertwined in ways often presented on this podcast and in the waymaking approach in general—two sides of the same coin, and explore how the hippocampus accomplishes this extraordinary feat by constructing cognitive maps (according to Nadel) representing extended spatial contexts, creating neural trajectories linking parts of events across time, and using these maps and trajectories to simulate possible futures.
Much of the core insight—that the hippocampus ‘stitches together’ spatiotemporally disparate experiences into a coherent framework—can be found in the early work from the beginning. Andrea has tried to show in her academic work that this ‘stitching together’ is representational (a form of external communication about what is already continuous).
What emerges is the recognition that memory and navigation are threaded together (or even ‘two dynamic paths to the same dynamic lake’), that space and time are not separate scaffolds but interwoven constructions of the mind, mediated by this remarkable neural architecture.
beyond space and time
Nadel does not seem to think of emotion as cognitive, which is something perhaps to be furthered explored by the two of them, as they seem to have different ideas of what emotion and cognition mean.
When asked about emotion, love, or compassion, Lynn is refreshingly direct: “I have no insights into it. I... I struggle.”
The hippocampus, he suggests, is a “purely cognitive, purely knowledge-based system” that can influence emotional and social domains but isn’t fundamental to them. It makes contextual contributions—knowing when restaurant voice versus home voice is appropriate—but doesn’t explain emotion itself.
Yet there’s something profound in the conversation that goes beyond these mechanics. When asked if there’s any connection between his work and care or love, Nadel initially demurs. But then Andrea suggests: if we think of the hippocampus as a way we communicate with ourselves, constantly updating our knowledge to stay true to reality rather than clinging to outdated models, then it could be about “extending the circle of care.” She is getting at the idea that emotion is another way we make, and also cognitive, and this has a lot to do with what and how we navigate.
“Your memories, you are your memories, your memories are in constant dialogue with the real world, basically with everything you’re putting in, whatever you’re watching on YouTube, the people that are around you, those are shifting the algorithm, so to speak, all the time.”
Both the 1978 book and the 2021 paper are open access, so we encourage you to read them if you wish to dive deeper. Here are some further quotes from both below.
quotes from the 1978 book:
On bridging gaps and action at a distance: “The place system permits an animal to locate itself in a familiar environment without reference to any specific sensory input, to go from one place to another independent of particular inputs (cues) or outputs (responses), and to link together conceptually parts of an environment which have never been experienced at the same time.”
On the hippocampus as the stitching mechanism: “We shall call the system which generates this absolute space a cognitive map and will identify it with the hippocampus... This system underlies the notion of absolute, unitary space, which is a non-centred stationary framework through which the organism and its egocentric spaces move.”
On the Kantian absolute space: “In contrast to this view, we think that the concept of absolute space is primary and that its elaboration does not depend upon prior notions of relative space... There exists at least one neural system which provides the basis for an integrated model of the environment. This system underlies the notion of absolute, unitary space.”
On constellation-like flexibility: “Each new item which is located on a map is automatically related to every other place and item already on the map. A change in a feature of the landscape occasions only a single alteration in a map, yet it changes every route statement in which that feature occurs.”
On the non-object-dependent nature of places: “The constituents of space are places... Places and space are not, in our view, defined in terms of objects or the relations between objects. The absolute space defined by Kant exists in the absence of objects... This freedom from reference to any specific object or set of objects is one of the most important properties of maps.”
On connecting experiences across time: “Since each representation of a stimulus is encoded in terms of its spatial relations to other stimuli, an identical stimulus occurring in different parts of the same environment, or in totally different environments, will have distinct, and differentiable, representations in each case. This, of course, is the way in which a spatio-temporal framework solves, by its very structure, the problem of re-identification so central to our philosophical discussion.”
And on the innate spatial framework: “We have organized this chapter around the dichotomy between absolute and relative space in the hope of showing how the choice of either of these as prior crucially influences the ability of any theory to cope with space perception... It seems reasonable to conclude, first, that there is a clear need for the concept of unitary space. Further, it appears that this framework cannot be acquired through experience; it must be available soon after birth, for the processes of localization, identification and the coherent organization of experience depend on it.”
Quotes from the paper they discuss here:
The 2021 Paper: “The Hippocampal Formation and Action at a Distance,”
In this paper, Nadel deepens these insights while moving toward a more integrated view. He writes:
“The question of why our conceptions of space and time are intertwined with memory in the hippocampal formation is at the forefront of much current theorizing about this brain system. In this article I argue that animals bridge spatial and temporal gaps through the creation of internal models that allow them to act on the basis of things that exist in a distant place and/or existed at a different time. The hippocampal formation plays a critical role in these processes by stitching together spatiotemporally disparate entities and events. It does this by 1) constructing cognitive maps that represent extended spatial contexts, incorporating and linking aspects of an environment that may never have been experienced together; 2) creating neural trajectories that link the parts of an event, whether they occur in close temporal proximity or not, enabling the construction of event representations even when elements of that event were experienced at quite different times; and 3) using these maps and trajectories to simulate possible futures. As a function of these hippocampally driven processes, our subjective sense of both space and time are interwoven constructions of the mind, much as the philosopher Immanuel Kant postulated.”
He continues: “Mediated action at a distance is central to much of what psychologists care about, given that behavior is frequently motivated by things that are at a spatial and/or temporal remove from the here and now. I will argue that mediating action at a distance is so important that a brain system, centered on the hippocampal formation, is largely devoted to carrying it out.”
And crucially: “Without a hippocampal formation, I will argue, organisms are largely incapable of escaping the here and now—a state of being captured in the title of Suzanne Corkin’s book about the famous amnesic patient H.M.: ‘Permanent Present Tense.’”
Nadel reflects on the journey we’ve already been discussing, writing:
“Nearly 45 years ago we proposed the ‘cognitive map’ theory of hippocampal function. Spurred by the discovery by O’Keefe and Dostrovsky of place cells in the hippocampus, this theory spelled out the ways in which this brain structure, and its neighbors, allowed organisms to move about and explore space and to store in memory specific experiences that played out over time. Much has been discovered about the hippocampus and its neural confederates since then, most of which is consistent with the broad outlines of cognitive map theory. But one enigma remains: Why is it that the same neural system is so intimately involved in aspects of space and time and memory?”
Seahorse, from the series Fishers and Fish (N74) for Duke brand cigarettes, Knapp & Company playing cars, W Duke Sons & Co 1888
quotes Andrea reads in intro from Lynn and John’s book (1978):
1. On “Action at a Distance” and bridging gaps (parallel to Nadel paper):
“The place system permits an animal to locate itself in a familiar environment without reference to any specific sensory input, to go from one place to another independent of particular inputs (cues) or outputs (responses), and to link together conceptually parts of an environment which have never been experienced at the same time.”
2. On the Hippocampus as stitching mechanism:
“We shall call the system which generates this absolute space a cognitive map and will identify it with the hippocampus... This system underlies the notion of absolute, unitary space, which is a non-centred stationary framework through which the organism and its egocentric spaces move.”
3. On Kantian absolute space:
“In contrast to this view, we think that the concept of absolute space is primary and that its elaboration does not depend upon prior notions of relative space... There exists at least one neural system which provides the basis for an integrated model of the environment. This system underlies the notion of absolute, unitary space.”
4. multiple representations/Constellation-like flexibility:
“Each new item which is located on a map is automatically related to every other place and item already on the map. A change in a feature of the landscape occasions only a single alteration in a map, yet it changes every route statement in which that feature occurs.”
5. non-object-dependent nature of places:
“The constituents of space are places... Places and space are not, in our view, defined in terms of objects or the relations between objects. The absolute space defined by Kant exists in the absence of objects... This freedom from reference to any specific object or set of objects is one of the most important properties of maps.”
6. On Connecting Experiences Across Time (memory function):
“Since each representation of a stimulus is encoded in terms of its spatial relations to other stimuli, an identical stimulus occurring in different parts of the same environment, or in totally different environments, will have distinct, and differentiable, representations in each case. This, of course, is the way in which a spatio-temporal framework solves, by its very structure, the problem of re-identification so central to our philosophical discussion.”
7. On the Innate Spatial Framework (Kantian a priori):
“We have organized this chapter around the dichotomy between absolute and relative space in the hope of showing how the choice of either of these as prior crucially influences the ability of any theory to cope with space perception... It seems reasonable to conclude, first, that there is a clear need for the concept of unitary space. Further, it appears that this framework cannot be acquired through experience; it must be available soon after birth, for the processes of localization, identification and the coherent organization of experience depend on it.”
More quotes discussed from the Action at a Distance paper:
“The question of why our conceptions of space and time are intertwined with memory in the hippocampal formation is at the forefront of much current theorizing about this brain system. In this article I argue that animals bridge spatial and temporal gaps through the creation of internal models that allow them to act on the basis of things that exist in a distant place and/or existed at a different time. The hippocampal formation plays a critical role in these processes by stitching together spatiotemporally disparate entities and events. It does this by 1) constructing cognitive maps that represent extended spatial contexts, incorporating and linking aspects of an environment that may never have been experienced together; 2) creating neural trajectories that link the parts of an event, whether they occur in close temporal proximity or not, enabling the construction of event representations even when elements of that event were experienced at quite different times; and 3) using these maps and trajectories to simulate possible futures. As a function of these hippocampally driven processes, our subjective sense of both space and time are interwoven constructions of the mind, much as the philosopher Immanuel Kant postulated.”
“Mediated action at a distance is central to much of what psychologists care about, given that behavior is frequently motivated by things that are at a spatial and/or temporal remove from the here and now. I will argue that mediating action at a distance is so important that a brain system, centered on the hippocampal formation, is largely devoted to carrying it out.”
“Without a hippocampal formation, I will argue, organisms are largely incapable of escaping the here and now—a state of being captured quite well in the title of Suzanne Corkin’s book about the famous amnesic patient H.M.: “Permanent Present Tense.””
clouds in Boulder, 2025, Andrea Hiott
be well out there.