Inspired by Hippocampal place cells

Place Field

Counterpart to Static document tree index

An adaptive document topology: frequently visited nodes sharpen, traversed edges reinforce, unused branches decay, and landmarks emerge from query patterns.

benchmarked

Specimen. Hippocampus · place cells

Key properties

01Place field sharpening: frequently queried nodes develop richer summaries

02Stigmergic edge reinforcement: cross-reference edges strengthen with repeated traversal

03Selective pruning: unused branches decay, keeping the tree lean and relevant

04Multi-resolution navigation: coarse-to-fine traversal guided by node importance

05Landmark formation: heavily accessed nodes become navigation shortcuts

06Consolidation sweeps: periodic summary quality improvement for active regions

Operation complexity

Side-by-side with the classical counterpart.

Operation	Place Field	Static document tree index
navigate	O(log N)	O(log N) (tree search)
add_node	O(1)	O(1)
record_access	O(1) amortized	N/A
tick (decay + prune)	O(N) amortized	N/A
landmark detection	O(1) per access	N/A

Interface preview

pub struct PlaceField { /* ... */ }

impl PlaceField {
    pub fn new(config: PlaceFieldConfig) -> Self;

    pub fn add_node(&mut self, title: String, summary: String,
        page_range: (usize, usize), parent: Option<u32>) -> Result<u32, PlaceFieldError>;
    pub fn navigate(&self, keywords: &[String], max_nodes: usize) -> NavigationResult;

    pub fn record_access(&mut self, node_id: u32, yield_score: f32) -> Result<(), PlaceFieldError>;
    pub fn landmarks(&self) -> Vec<u32>;

    pub fn tick(&mut self) -> TickReport;
}

Where this matters

PDF.js / Document Viewers · Table of Contents / Page Index

Today	With Place Field	How
Static ToC that never learns from reader behavior	Adaptive topology that sharpens around frequently visited sections	Place field reinforcement strengthens accessed nodes and traversed edges
Flat linear structure for cross-references	Weighted cross-reference graph with decay	Edges strengthen with use and decay without; irrelevant links fade naturally
No concept of navigation landmarks	Automatic landmark formation for high-traffic nodes	Nodes exceeding access threshold become navigation shortcuts

Interactive simulation

Node size: place-field sharpness. Dashed: landmark shortcuts. Amber arcs: cross-references that strengthen with use.

Field notes

Waiting for the first reader…

Queries: 0
Avg hops: –
Static hops: 2.00
Landmarks: 0
Cross-refs: 0
Sharpest: –

Tick 0 / 300Static tree: always 2 hops · importance decay 2% per tick

Figure. Place Field Navigation at tick 0 of 300. Static tree: always 2 hops · importance decay 2% per tick.

Illustrative simulation, not a benchmark · Mutuus Research, ByteQuilt

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