When Truthful Representations Flip Under Deceptive Instructions?

Fuente: arXiv
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Main Authors: Long, Xianxuan, Fu, Yao, Li, Runchao, Sheng, Mu, Yu, Haotian, Han, Xiaotian, Li, Pan
Format: Preprint
Published: 2025
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author Long, Xianxuan
Fu, Yao
Li, Runchao
Sheng, Mu
Yu, Haotian
Han, Xiaotian
Li, Pan
author_facet Long, Xianxuan
Fu, Yao
Li, Runchao
Sheng, Mu
Yu, Haotian
Han, Xiaotian
Li, Pan
contents Large language models (LLMs) tend to follow maliciously crafted instructions to generate deceptive responses, posing safety challenges. How deceptive instructions alter the internal representations of LLM compared to truthful ones remains poorly understood beyond output analysis. To bridge this gap, we investigate when and how these representations ``flip'', such as from truthful to deceptive, under deceptive versus truthful/neutral instructions. Analyzing the internal representations of Llama-3.1-8B-Instruct and Gemma-2-9B-Instruct on a factual verification task, we find the model's instructed True/False output is predictable via linear probes across all conditions based on the internal representation. Further, we use Sparse Autoencoders (SAEs) to show that the Deceptive instructions induce significant representational shifts compared to Truthful/Neutral representations (which are similar), concentrated in early-to-mid layers and detectable even on complex datasets. We also identify specific SAE features highly sensitive to deceptive instruction and use targeted visualizations to confirm distinct truthful/deceptive representational subspaces. % Our analysis pinpoints layer-wise and feature-level correlates of instructed dishonesty, offering insights for LLM detection and control. Our findings expose feature- and layer-level signatures of deception, offering new insights for detecting and mitigating instructed dishonesty in LLMs.
format Preprint
id arxiv_https___arxiv_org_abs_2507_22149
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle When Truthful Representations Flip Under Deceptive Instructions?
Long, Xianxuan
Fu, Yao
Li, Runchao
Sheng, Mu
Yu, Haotian
Han, Xiaotian
Li, Pan
Artificial Intelligence
Machine Learning
Large language models (LLMs) tend to follow maliciously crafted instructions to generate deceptive responses, posing safety challenges. How deceptive instructions alter the internal representations of LLM compared to truthful ones remains poorly understood beyond output analysis. To bridge this gap, we investigate when and how these representations ``flip'', such as from truthful to deceptive, under deceptive versus truthful/neutral instructions. Analyzing the internal representations of Llama-3.1-8B-Instruct and Gemma-2-9B-Instruct on a factual verification task, we find the model's instructed True/False output is predictable via linear probes across all conditions based on the internal representation. Further, we use Sparse Autoencoders (SAEs) to show that the Deceptive instructions induce significant representational shifts compared to Truthful/Neutral representations (which are similar), concentrated in early-to-mid layers and detectable even on complex datasets. We also identify specific SAE features highly sensitive to deceptive instruction and use targeted visualizations to confirm distinct truthful/deceptive representational subspaces. % Our analysis pinpoints layer-wise and feature-level correlates of instructed dishonesty, offering insights for LLM detection and control. Our findings expose feature- and layer-level signatures of deception, offering new insights for detecting and mitigating instructed dishonesty in LLMs.
title When Truthful Representations Flip Under Deceptive Instructions?
topic Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2507.22149