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Mengnan Du

36 accepted papers

2025

A Survey on Sparse Autoencoders: Interpreting the Internal Mechanisms of Large Language Models

EMNLP 2025

Large Language Models (LLMs) have transformed natural language processing, yet their internal mechanisms remain largely opaque. Recently, mechanistic interpretability has attracted significant attention from the research community as a means to understand the inner workings of LLMs. Among various me

Cited by 0SourcePDFScholar
2025

Beyond Input Activations: Identifying Influential Latents by Gradient Sparse Autoencoders

EMNLP 2025

Sparse Autoencoders (SAEs) have recently emerged as powerful tools for interpreting and steering the internal representations of large language models (LLMs). However, conventional approaches to analyzing SAEs typically rely solely on input-side activations, without considering the influence between

2025

Beyond Single Concept Vector: Modeling Concept Subspace in LLMs with Gaussian Distribution

ICLR 2025poster

Probing learned concepts in large language models (LLMs) is crucial for understanding how semantic knowledge is encoded internally. Training linear classifiers on probing tasks is a principle approach to denote the vector of a certain concept in the representation space. However, the single vector i…

2025

Comparative Analysis of Demonstration Selection Algorithms for In-Context Learning in Large Language Models (Student Abstract)

AAAI 2025technical

Demonstration selection algorithms play a crucial role in optimizing Large Language Models' (LLMs) in-context learning performance. Despite numerous proposed algorithms, their comparative effectiveness remains understudied. We present a comprehensive evaluation of six state-of-the-art demonstration…

2025

Concept-Centric Token Interpretation for Vector-Quantized Generative Models

ICML 2025poster

Vector-Quantized Generative Models (VQGMs) have emerged as powerful tools for image generation. However, the key component of VQGMs---the codebook of discrete tokens---is still not well understood, e.g., which tokens are critical to generate an image of a certain concept? This paper introduces Conce…

2025

Data-centric NLP Backdoor Defense from the Lens of Memorization

NAACL 2025findings

Backdoor attack is a severe threat to the trustworthiness of DNN-based language models. In this paper, we first extend the definition of memorization of language models from sample-wise to more fine-grained sentence element-wise (e.g., word, phrase, structure, and style), and then point out that lan…

Cited by 3SourcePDFScholar
2025

Exploring Concept Depth: How Large Language Models Acquire Knowledge and Concept at Different Layers?

COLING 2025main

Large language models (LLMs) have shown remarkable performances across a wide range of tasks. However, the mechanisms by which these models encode tasks of varying complexities remain poorly understood. In this paper, we explore the hypothesis that LLMs process concepts of varying complexities in di…

2025

Feature Extraction and Steering for Enhanced Chain-of-Thought Reasoning in Language Models

EMNLP 2025

Large Language Models (LLMs) demonstrate the ability to solve reasoning and mathematical problems using the Chain-of-Thought (CoT) technique. Expanding CoT length, as seen in models such as DeepSeek-R1, significantly enhances this reasoning for complex problems, but requires costly and high-quality

2025

From Commands to Prompts: LLM-based Semantic File System for AIOS

ICLR 2025poster

Large language models (LLMs) have demonstrated significant potential in the development of intelligent LLM-based agents. However, when users use these agent applications to perform file operations, their interaction with the file system still remains the traditional paradigm: reliant on manual navig…

2025

Improving LLM Reasoning through Interpretable Role-Playing Steering

EMNLP 2025

Role-playing has emerged as an effective technique for enhancing the reasoning capabilities of large language models (LLMs). However, existing methods primarily rely on prompt engineering, which often lacks stability and interpretability. In this paper, we introduce Sparse Autoencoder Role-Playing S

Cited by 0SourcePDFScholar
2025

Invisible Backdoor Attack against Self-supervised Learning

CVPR 2025poster

Self-supervised learning (SSL) models are vulnerable to backdoor attacks. Existing backdoor attacks that are effective in SSL often involve noticeable triggers, like colored patches or visible noise, which are vulnerable to human inspection. This paper proposes an imperceptible and effective backdoo…

2025

Language Ranker: A Metric for Quantifying LLM Performance Across High and Low-Resource Languages

AAAI 2025technical

The development of Large Language Models (LLMs) relies on extensive text corpora, which are often unevenly distributed across languages. This imbalance results in LLMs performing significantly better on high-resource languages like English, German, and French, while their capabilities in low-resourc…

2025

Large Vision-Language Model Alignment and Misalignment: A Survey Through the Lens of Explainability

EMNLP 2025

Large Vision-Language Models (LVLMs) have demonstrated remarkable capabilities in processing both visual and textual information. However, the critical challenge of alignment between visual and textual representations is not fully understood. This survey presents a comprehensive examination of align

Cited by 0SourcePDFScholar
2025

Massive Values in Self-Attention Modules are the Key to Contextual Knowledge Understanding

ICML 2025poster

Large language models (LLMs) have achieved remarkable success in contextual knowledge understanding. In this paper, we show for the first time that these concentrated massive values consistently emerge in specific regions of attention queries (Q) and keys (K) while not having such patterns in values…

2025

SAE-SSV: Supervised Steering in Sparse Representation Spaces for Reliable Control of Language Models

EMNLP 2025

Large language models (LLMs) have demonstrated impressive capabilities in natural language understanding and generation, but controlling their behavior reliably remains challenging, especially in open-ended generation settings. This paper introduces a novel supervised steering approach that operates

2024

Data-Centric Explainable Debiasing for Improving Fairness in Pre-trained Language Models

ACL 2024findings

Human-like social bias of pre-trained language models (PLMs) on downstream tasks have attracted increasing attention. The potential flaws in the training data are the main factor that causes unfairness in PLMs. Existing data-centric debiasing strategies mainly leverage explicit bias words (defined a…

2024

Explaining Time Series via Contrastive and Locally Sparse Perturbations

ICLR 2024poster

Explaining multivariate time series is a compound challenge, as it requires identifying important locations in the time series and matching complex temporal patterns. Although previous saliency-based methods addressed the challenges, their perturbation may not alleviate the distribution shift issue,…

2024

Mitigating Shortcuts in Language Models with Soft Label Encoding

COLING 2024main

Recent research has shown that large language models rely on spurious correlations in the data for natural language understanding (NLU) tasks. In this work, we aim to answer the following research question: Can we reduce spurious correlations by modifying the ground truth labels of the training data…

2024

Secure Your Model: An Effective Key Prompt Protection Mechanism for Large Language Models

NAACL 2024findings

Large language models (LLMs) have notably revolutionized many domains within natural language processing due to their exceptional performance. Their security has become increasingly vital. This study is centered on protecting LLMs against unauthorized access and potential theft. We propose a simple…

2024

Strategic Demonstration Selection for Improved Fairness in LLM In-Context Learning

EMNLP 2024main

Recent studies highlight the effectiveness of using in-context learning (ICL) to steer large language models (LLMs) in processing tabular data, a challenging task given the structured nature of such data. Despite advancements in performance, the fairness implications of these methods are less unders…

Cited by 3SourcePDFScholar
2024

TVE: Learning Meta-attribution for Transferable Vision Explainer

ICML 2024poster

Explainable machine learning significantly improves the transparency of deep neural networks. However, existing work is constrained to explaining the behavior of individual model predictions, and lacks the ability to transfer the explanation across various models and tasks. This limitation results i…

2024

The Impact of Reasoning Step Length on Large Language Models

ACL 2024findings

Chain of Thought (CoT) is significant in improving the reasoning abilities of large language models (LLMs). However, the correlation between the effectiveness of CoT and the length of reasoning steps in prompts remains largely unknown. To shed light on this, we have conducted several empirical exper…

Cited by 85SourcePDFScholar
2024

Unveiling Project-Specific Bias in Neural Code Models

COLING 2024main

Deep learning has introduced significant improvements in many software analysis tasks. Although the Large Language Models (LLMs) based neural code models demonstrate commendable performance when trained and tested within the intra-project independent and identically distributed (IID) setting, they o…

2023

$\mathcal{M}^4$: A Unified XAI Benchmark for Faithfulness Evaluation of Feature Attribution Methods across Metrics, Modalities and Models

NeurIPS 2023poster

While Explainable Artificial Intelligence (XAI) techniques have been widely studied to explain predictions made by deep neural networks, the way to evaluate the faithfulness of explanation results remains challenging, due to the heterogeneity of explanations for various models and the lack of ground…

2023

Black-box Backdoor Defense via Zero-shot Image Purification

NeurIPS 2023poster

Backdoor attacks inject poisoned samples into the training data, resulting in the misclassification of the poisoned input during a model's deployment. Defending against such attacks is challenging, especially for real-world black-box models where only query access is permitted. In this paper, we pro…

2023

FAIRER: Fairness as Decision Rationale Alignment

ICML 2023poster

Deep neural networks (DNNs) have made significant progress, but often suffer from fairness issues, as deep models typically show distinct accuracy differences among certain subgroups (e.g., males and females). Existing research addresses this critical issue by employing fairness-aware loss functions…

Cited by 24SourcePDFScholar
2023

Prompt Tuning Pushes Farther, Contrastive Learning Pulls Closer: A Two-Stage Approach to Mitigate Social Biases

ACL 2023long

As the representation capability of Pre-trained Language Models (PLMs) improve, there is growing concern that they will inherit social biases from unprocessed corpora. Most previous debiasing techniques used Counterfactual Data Augmentation (CDA) to balance the training corpus. However, CDA slightly…

Cited by 12SourcePDFScholar
2022

Accelerating Shapley Explanation via Contributive Cooperator Selection

ICML 2022spotlight

Even though Shapley value provides an effective explanation for a DNN model prediction, the computation relies on the enumeration of all possible input feature coalitions, which leads to the exponentially growing complexity. To address this problem, we propose a novel method SHEAR to significantly a…

2022

DEGREE: Decomposition Based Explanation for Graph Neural Networks

ICLR 2022poster

Graph Neural Networks (GNNs) are gaining extensive attention for their application in graph data. However, the black-box nature of GNNs prevents users from understanding and trusting the models, thus hampering their applicability. Whereas explaining GNNs remains a challenge, most existing methods fa…

2021

A Unified Taylor Framework for Revisiting Attribution Methods

AAAI 2021technical

Attribution methods have been developed to understand the decision making process of machine learning models, especially deep neural networks, by assigning importance scores to individual features. Existing attribution methods often built upon empirical intuitions and heuristics. There still lacks a…

Cited by 20SourcePDFScholar
2021

Fairness via Representation Neutralization

NeurIPS 2021poster

Existing bias mitigation methods for DNN models primarily work on learning debiased encoders. This process not only requires a lot of instance-level annotations for sensitive attributes, it also does not guarantee that all fairness sensitive information has been removed from the encoder. To address…

Cited by 95SourcePDFScholar
2021

Towards Interpreting and Mitigating Shortcut Learning Behavior of NLU models

NAACL 2021long

Recent studies indicate that NLU models are prone to rely on shortcut features for prediction, without achieving true language understanding. As a result, these models fail to generalize to real-world out-of-distribution data. In this work, we show that the words in the NLU training set can be model…

Cited by 107SourcePDFScholar