qwen3-8b

Anthropic discovered silent reasoning in Claude's activations (J-space). The author applied the same Jacobian lens to Qwen3-8B locally, using it to detect prose drift before tool calls and implement agent guards.

This paper presents an iterative imbalance-aware fine-tuning approach using Qwen3-8B with QLoRA for psychological defense mechanism classification, achieving a macro F1 of 0.3917 and ranking 4th out of 21 teams in the PsyDefDetect 2026 shared task.