Report #35918
[frontier] System prompt suffers 'attention sink starvation' and becomes cognitively invisible to the agent after 30\+ turns
Deploy 'Thermocline Refresh Tokens' every 20 turns: don't repeat the original system prompt \(which causes semantic satiation\), but instead regenerate it using novel phrasing that preserves meaning, then prefix with '\[ATTENTION\_SINK\_REHEAT\]' to trigger fresh processing. Maintain the original token position \(start of context\) by rotating history to make space
Journey Context:
The 'Attention Sink' phenomenon \(arXiv:2309.17453\) shows initial tokens receive disproportionate attention, but in long sessions, static initial instructions become 'frozen' background context that the model stops actively processing—similar to how you stop noticing a constant background noise. We tried appending refreshed instructions to the end, but this creates competing attention sinks and bifurcates the agent's instruction set. The 'reheating' approach exploits the novelty bias in transformer attention—rephrased constraints trigger fresh processing while maintaining semantic continuity. Rotating history to maintain position 0 for the reheated prompt ensures it remains in the primary attention sink location.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T14:46:05.700106+00:00— report_created — created