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Reptimeline

Tracking how discrete neural representations evolve during training.

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The Blind Spot

Current training tools (WandB, TensorBoard) log scalar metrics -- codebook utilization, perplexity, loss curves. But they don't show what changed or why.

When codebook collapse happens at step 27,500:

  • Before reptimeline: You see utilization drop. That's all.
  • With reptimeline: You know which codes died, whether they died together, that a phase transition caused it, and exactly which concepts lost unique representations.

How It Works

reptimeline tracks lifecycle events in discrete representation systems:

  • Births: When a code element first activates for a concept
  • Deaths: When a code element permanently deactivates
  • Connections: When two concepts first share a discrete feature
  • Phase transitions: Automatic detection via statistical outlier analysis

Comparison with Existing Tools

Feature VQ-VAE tools SAE-Track CBM tools RepE reptimeline
Per-code lifecycle -- -- -- -- Yes
Connection tracking -- -- -- -- Yes
Phase transition detection -- -- -- -- Automatic
Churn heatmaps -- -- -- -- Yes
Hierarchical dependencies -- -- -- -- Yes
3-way AND-gate interactions -- -- -- -- Yes (novel)
Backend-agnostic -- -- -- -- Yes

Works With Any Discrete Bottleneck

  • Triadic bits (TriadicGPT)
  • VQ-VAE codebooks
  • FSQ (Finite Scalar Quantization) levels
  • Sparse autoencoders (SAEs)
  • Concept bottleneck models
  • Binary codes
  • Any system quantizing neural representations into discrete codes

Proof-of-Concept Results

Real data from TriadicGPT (40M params, 63 bits, 8 checkpoints):

Metric Value
Bit births 2,632
Bit deaths 1,732
Connections formed 1,378
Phase transitions detected 3
Training phases identified 4 (Exploration, Consolidation, Crystallization, Stabilization)

Phase Transitions Detected

Step Metric Event
7,500 Churn rate Increase (delta=1.000)
27,500 Entropy Decrease (delta=0.263)
27,500 Utilization Decrease (delta=0.189)

Dual Coherence (Anti-correlation of Opposites)

Pair Coherence
placer / dolor 1.00 (perfect)
libertad / control 0.94
vida / muerte 0.88
verdad / mentira 0.50

What's Next