Papers › Pierce the Mists, Greet the Sky: Decipher Knowledge Overshadowing via Knowledge...

Pierce the Mists, Greet the Sky: Decipher Knowledge Overshadowing via Knowledge Circuit Analysis

20 May 2025arXiv:2505.14406archive 2025-07-28

Haoming Huang, Yibo Yan, Jiahao Huo, Xin Zou, Xinfeng Li, Kun Wang, Xuming Hu

Large Language Models (LLMs), despite their remarkable capabilities, are hampered by hallucinations. A particularly challenging variant, knowledge overshadowing, occurs when one piece of activated knowledge inadvertently masks another relevant piece, leading to erroneous outputs even with high-quality training data. Current understanding of overshadowing is largely confined to inference-time observations, lacking deep insights into its origins and internal mechanisms during model training. Therefore, we introduce PhantomCircuit, a novel framework designed to comprehensively analyze and detect knowledge overshadowing. By innovatively employing knowledge circuit analysis, PhantomCircuit dissects the internal workings of attention heads, tracing how competing knowledge pathways contribute to the overshadowing phenomenon and its evolution throughout the training process. Extensive experiments demonstrate PhantomCircuit's effectiveness in identifying such instances, offering novel insights into this elusive hallucination and providing the research community with a new methodological lens for its potential mitigation.

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Code

Syntology Ran 7 of 7 code samples harvested from 1 repository linked to this paper; 0 have no recorded run. Of those that ran: 1 ran · honoured contract; 1 ran · violated contract; 4 ran · our draft was wrong; 1 ran with no contract checked.

By repository: found in paper text by Syntology: 7 samples from 1 repository, 7 ran. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

halfmorepiece/PhantomCircuit found in paper text by Syntology report

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Code Syntology ran Syntology

7 samples harvested; 7 ran; 1 honoured the contract we drafted; 0 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

1ran · honoured contract
1ran · violated contract
4ran · our draft was wrong
1ran

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_is_eos_token halfmorepiece/PhantomCircuit/co_xsub_identifier.py found in paper text by Syntology ran · violated contract Apache-2.0 (permissive) · 011699c99d460851 · report
clean_prompt_tokens halfmorepiece/PhantomCircuit/co_xsub_identifier.py found in paper text by Syntology ran · our draft was wrong Apache-2.0 (permissive) · 942e288739fc5fad · report
compute_logprob_variance_across_masks halfmorepiece/PhantomCircuit/co_xsub_identifier.py found in paper text by Syntology ran · our draft was wrong Apache-2.0 (permissive) · ff663579f9e9503f · report
get_top_k_predictions halfmorepiece/PhantomCircuit/co_xsub_identifier.py found in paper text by Syntology ran Apache-2.0 (permissive) · 4e43ea55d6c051ca · report
identify_xsub_by_phantomcircuit halfmorepiece/PhantomCircuit/co_xsub_identifier.py found in paper text by Syntology ran · our draft was wrong Apache-2.0 (permissive) · de73d191312197fe · report
safe_to_str_tokens halfmorepiece/PhantomCircuit/co_xsub_identifier.py found in paper text by Syntology ran · our draft was wrong Apache-2.0 (permissive) · ce9db70729fd9a34 · report
safe_to_tokens halfmorepiece/PhantomCircuit/co_xsub_identifier.py found in paper text by Syntology ran · honoured contract Apache-2.0 (permissive) · 7967a02919473231 · report

Tasks

Hallucination

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Methods

AttentionSoftmax

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