
Mode collapse is a persistent challenge in generative modeling and appears in autoregressive text generation as behaviors ranging from explicit looping to gradual loss of diversity and premature trajectory convergence. We take a dynamical-systems view and reinterpret mode collapse as reduced state-space accessibility caused by geometric collapse: during generation, the model’s internal trajectory becomes confined to a low-dimensional region of its representation space.
This implies mode collapse is not purely a token-level phenomenon and cannot be reliably solved by symbolic constraints or probability-only decoding heuristics. Guided by this perspective, we propose Reinforced Mode Regulation (RMR), a lightweight, online state-space intervention that regulates dominant self-reinforcing directions in the Transformer value cache, implemented as low-rank damping. Across multiple large language models, RMR substantially reduces mode collapse and enables stable, high-quality generation at extremely low entropy rates, down to 0.8 nats/step, whereas standard decoding typically collapses near 2.0 nats/step.
References
Du, X., & Tanaka-Ishii, K. (2026). Escaping Mode Collapse in LLM Generation.