Project Janus: Engineering the "Shape" of Attention (Step 4.5k Update)

We are currently training Janus-Small (40M params) on the TinyStories dataset. This isn’t a standard training run; it’s a validation of Mechanistic Regularization—a technique where we actively steer the model’s internal geometry using a differentiable loss term that penalizes redundant attention heads.

At Step 4,500 (22% of the way to convergence), the telemetry is validating our core hypothesis: that we can force a Transformer to be structurally efficient without sacrificing performance.

The Telemetry (Step 4,500)

The model is currently outperforming our standard baseline in structural metrics while maintaining parity in perplexity.

• Task Loss: 1.53 (Improving, -0.023 in last 100 steps).

• Structural Redundancy (\sigma_a): 0.27 (Stable).

• Context: Standard baselines at this scale typically sit at ~0.46. Janus is operating with ~40% less internal redundancy.

• Steering Pressure: 0.009. We are currently in the “Release” phase of our Trapezoidal Schedule, allowing the model to fine-tune the efficient structures it crystallized earlier.

The Topology: “The Information Funnel”

Our layer-wise analysis confirms that Gradient Steering (scaling pressure by depth) has successfully sculpted the model’s internal information flow. We are seeing a clear “Funnel” topology:

• Input (Layer 0): High Rank (~99), High Redundancy (~0.60). The model retains a broad, robust scan of the input tokens.

• Output (Layer 11): Collapsed Rank (~29), Near-Zero Redundancy (~0.08). The model forces orthogonal decision-making at the final layer.

Qualitative Audit: The “Creative Bias”

We ran a diagnostic task battery to check for “brain damage” (a common side effect of structural pruning). The results were surprising. The model has mastered grammar and causal logic, but exhibits a fascinating bias toward Narrative Coherence over Fact Retrieval.

Prompt: “Lily has a blue hat. Tom has a red hat. Lily is wearing a…”

Janus Output: “Lily is wearing a purple hat. She has a purple flower on her head.”

Instead of simply retrieving the variable (“blue”), the model hallucinated a new color to match the context of the “flower” it invented in the next sentence. It prioritized Thematic Consistency over Recall.

Next Steps

We are letting the run continue to 20,000 steps to observe if this “Funnel” topology holds at full convergence. If the efficiency gap persists, we will be releasing the JanusBlock code and the training recipes.

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The continuation of this work can be found here:

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