Jett Janiak


2024

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An Adversarial Example for Direct Logit Attribution: Memory Management in GELU-4L
Jett Janiak | Can Rager | James Dao | Yeu-Tong Lau
Proceedings of the 7th BlackboxNLP Workshop: Analyzing and Interpreting Neural Networks for NLP

Prior work suggests that language models manage the limited bandwidth of the residual stream through a “memory management” mechanism, where certain attention heads and MLP layers clear residual stream directions set by earlier layers. Our study provides concrete evidence for this erasure phenomenon in a 4-layer transformer, identifying heads that consistently remove the output of earlier heads. We further demonstrate that direct logit attribution (DLA), a common technique for interpreting the output of intermediate transformer layers, can show misleading results by not accounting for erasure.