Navigational Mind

00 — The ‘seat’ of memory

Before 1953, memory was not associated with any one area of the brain. Lashley spent decades looking for the trace and though this is a long story and lots of debate, the idea was sort of that memory is everywhere and nowhere. But epilepsy and surgeons removing the medial temporal lobes of patients brought scientists to focus on the hippocampus. As part of this, Henry Moalison, a 27-year-old man with intractable epilepsy, had his hippoampi revoved and then his seizures improved but he could not form any new memories, or could not attach anything new to the memory he already had.

Note: The operation was experimental, performed on a patient in distress, and it destroyed a man's capacity to build a life in exchange for knowledge the rest of us now have. Scoville came to regard it as a mistake. H.M. spent fifty-five years being tested by researchers he met, each time, for the first time.

01 — The cognitive map

A cognitive map is often defined as a type of mental representation used by an individual to order their personal store of information about their everyday or metaphorical spatial environment, and the relationship of its component parts. The concept was introduced by Edward Tolman in 1948. He tried to explain the behavior of rats that appeared to learn the spatial layout of a maze, and subsequently the concept was applied to other animals, including humans The term was later generalized by some researchers, especially in the field of operations research, to refer to a kind of semantic network representing an individual's personal knowledge or schemas.

What is happening with the navigataional approach is that the map is becoming a ‘mapping’ and there are not stored internal representations but rahter different actions of communication at many scales, from the way we communicate with our own bodies as those bodies to the ways we communicate with all we encounter.

02 — Seeing cells fire

03 — Concepts and structure

If the grid code represents relations, it should appear wherever a task has map-like structure — including tasks with nothing spatial in them.

04 — Cognitive spaces: Doeller and others

The human-imaging side, pushed into theory: the hippocampal formation supplies a geometric format that any set of dimensions can be mapped into.

05 — Sound, smell, faces, status

The dimensions usually called "non-spatial."

Note: the hexadirectional fMRI signature is an indirect, population-level proxy for grid coding, not a recording of grid cells. Productive, and contested (like everything else).

06 — When the map is lost

07 — Imagining is continuous with remembering?

Amnesic patients couldn't remember their past. Then someone asked them to imagine lying on a white sandy beach, and that was also a struggle and most couldn't do that either, so there is a link here. Memory isn't a recording you play back; it's a construction, and imagination runs on similar ‘habits’ and ‘machinery’.

08 — Bodily action

The stronger claim: that remembering and imagining aren't just neurally similar but enacted — carried out by eyes, motor systems and place-cell sequences doing versions of what they do when you actually move and look.

What this section does and doesn't show: the evidence is strong for shared machinery — overlapping networks, re-enacted scanpaths, motor reactivation, sequences running both directions. It's weaker as proof that remembering and imagining are literally one bodily process. That's an interpretation (section 11), not a result. Say so on the page; it's a more interesting claim when presented as a claim.

09 —Selective attention; the worlds choose and the worlds chosen for us and the worlds we miss

10 — Attention writing to the hippocampus

11 — Rereading the map

If one system maps rooms, concepts, pitches and people, either "space" was the wrong word, or thinking was always more like moving than we assumed.

Some conversations about some of this

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Diaries, Talks, Creations: Here is playlist of messy attempts and conversations and experimenting towards this approach and articulating it across the usual bounds

Here are about 90 more talks on the subjects here form different philosophical POVs.