Lang Gao
Author directory2026
LITERARYBIGFIVE: Author-Personalized Text Generation in a Unified Interpretable Space
Jinghui Zhang | Lang Gao | Ao Li | Mingzhe Li | Ruihong Zeng | Zirui Song | Kentaro Inui | Xiuying Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Jinghui Zhang | Lang Gao | Ao Li | Mingzhe Li | Ruihong Zeng | Zirui Song | Kentaro Inui | Xiuying Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Personalized text generation for authors and literary writing is essential for applications such as adaptive writing assistants, creative support tools, and computational literary analysis. However, existing approaches to author modeling and personalization often represent writing behavior as independent labels, requiring large-scale corpus collection or fine-tuning for each author or stylistic category. Such formulations are costly, difficult to interpret, and poorly suited for generalizing across authors. Inspired by the Big Five theory of personality, we propose LiteraryBigFive, a framework that reframes authorial writing characteristics as coordinates within a unified and interpretable space. In this space, we derive each interpretable axis (e.g., Classicism, Emotionality) from activation-space contrasts between author-written and neutral passages, yielding distinct stylistic dimensions that allow texts or authors to be positioned within a five-dimensional system. Beyond localizing different authors, we further introduce an interpretable steering mechanism, which adaptively guides text generation toward target coordinates to perform author-personalized writing. Experimental results show that LiteraryBigFive improves authorial expressiveness while preserving semantic fidelity. The derived author per-axis scores strongly correlate with real-world literary consensus, offering transparent and interpretable explanations of author-specific generation behavior: https://github.com/Znull-1220/LiteraryBigFive.
SocialMaze: A Benchmark for Evaluating and Enhancing Social Reasoning in Large Language Models in Complex Social Environments
Zixiang Xu | Yanbo Wang | Yue Huang | Haomin Zhuang | Yujun Zhou | Jiayi Ye | Sixian Li | Zirui Song | Lang Gao | Chenxi Wang | Zhaorun Chen | Wang Pan | Yue Zhao | Jieyu Zhao | Xiangliang Zhang | Xiuying Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Zixiang Xu | Yanbo Wang | Yue Huang | Haomin Zhuang | Yujun Zhou | Jiayi Ye | Sixian Li | Zirui Song | Lang Gao | Chenxi Wang | Zhaorun Chen | Wang Pan | Yue Zhao | Jieyu Zhao | Xiangliang Zhang | Xiuying Chen
Findings of the Association for Computational Linguistics: EMNLP 2026
Large language models (LLMs) are increasingly deployed in socially grounded applications, where success requires interpreting context, inferring others’ mental states, and reasoning about unreliable information. Yet existing benchmarks rarely evaluate these demands jointly in complex, evolving settings. We introduce SocialMaze, a benchmark that organizes six tasks across social deduction games, daily-life interactions, and digital community platforms along three descriptive design axes: deep reasoning, dynamic interaction, and information uncertainty. These axes characterize intended sources of task difficulty rather than latent, factor-analytic dimensions of model capability. Automated checks and human validation support data quality. Evaluations of twelve proprietary and open-weight LLMs show substantial variation in the use of evolving interaction histories; stronger chain-of-thought reasoners perform better on tasks requiring deeper inference, while uncertainty consistently degrades performance. Reasoning workflows help weaker short-chain-of-thought backbones but saturate on stronger reasoners. Finally, targeted fine-tuning on curated reasoning traces substantially improves structured social-reasoning tasks, whereas transfer to language-aggregation tasks remains statistically inconclusive. The project homepage is available at https://xzx34.github.io/socialmaze/.
Beyond Survival: Evaluating LLMs in Social Deduction Games with Human-Aligned Strategies
Zirui Song | Yuan Huang | Junchang Liu | Haozhe Luo | Chenxi Wang | Lang Gao | Zixiang Xu | Bairui Zhang | Mingfei Han | Xiaojun Chang | Xiuying Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Zirui Song | Yuan Huang | Junchang Liu | Haozhe Luo | Chenxi Wang | Lang Gao | Zixiang Xu | Bairui Zhang | Mingfei Han | Xiaojun Chang | Xiuying Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Social deduction games like Werewolf combine language, reasoning, and strategy, providing a testbed for studying language and social intelligence. However, most studies reduce the game to LLM-based self-play, yielding templated utterances and anecdotal cases that overlook the richness of social gameplay. Evaluation further relies on coarse metrics such as survival time or subjective scoring due to the lack of quality reference data. To address these gaps, we curate a high-quality, human-verified, multilingual, and multimodal Werewolf dataset containing over 100 hours of video, 32.4M utterance tokens, and 15 rule variants. Based on this dataset, we propose a novel strategy-alignment evaluation that leverages the winning faction’s strategies as ground truth in two stages: 1) Speech evaluation, formulated as multiple-choice-style tasks that assess whether the model can adopt appropriate stances across five dimensions of social ability. 2) Decision evaluation, which assesses the model’s voting choices and opponent-role inferences. This framework enables a fine-grained evaluation of models’ linguistic and reasoning capabilities, while capturing their ability to generate strategically coherent gameplay. Our experiments show that state-of-the-art LLMs and VLMs exhibit diverse performance, with roughly half of the models in both modalities remaining below 0.50 accuracy, revealing clear gaps in deception and counterfactual reasoning.
MedRoundsQA: A Persona and Difficulty Aware Evaluation for Multi-Turn Medical Consultations
Youssef Mohamed | Ahmed Heakl | Qinrong Cui | Junhong Liang | Rafiq Ali | Bdour Babillie | Nazira Dunbayeva | Lang Gao | Omar Hussein | Ahmed Nada | Ahmed Mohamed Magdy Mohamed | Jinghui Liu | Salman Khan | Imran Razzak | Yuxia Wang | Xiuying Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Youssef Mohamed | Ahmed Heakl | Qinrong Cui | Junhong Liang | Rafiq Ali | Bdour Babillie | Nazira Dunbayeva | Lang Gao | Omar Hussein | Ahmed Nada | Ahmed Mohamed Magdy Mohamed | Jinghui Liu | Salman Khan | Imran Razzak | Yuxia Wang | Xiuying Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Medical benchmarks are dominated by single-turn, multiple-choice clinical cases that poorly reflect real consultations. Practically, clinicians elicit evidence interactively, and patient communication varies widely. We introduce MEDROUNDSQA, a multi-turn diagnostic benchmark derived from 1,387 clinical cases across 17 specialties. Each case is converted into a structured 24-slot clinical record and then instantiated as controlled doctor–patient dual-agent dialogues under varying patient personas, with the underlying clinical content held fixed. We further classify cases by difficulty using model-based uncertainty to enable easy-to-hard analysis. Evaluations of fifteen LLM doctor agents show that (i) moving from a single-turn diagnosis on the standardized records to multi-turn consultations causes large degradations of roughly 13–39 points; (ii) more turns reliably improve question relevance, but diagnostic accuracy exhibits diminishing returns and typically plateaus after 6–12 turns; and (iii) patient persona differences can shift diagnosis accuracy by about 7–8 points from the lowest to highest education levels, highlighting equity risks that single-turn benchmarks miss.
ServImage: An Image Generation and Editing Benchmark from Real-world Commercial Imaging Services
Fengxian Ji | Jingpu Yang | Zirui Song | Lang Gao | Junhong Liang | Zhenhao Chen | Jinghui Zhang | Xiuying Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Fengxian Ji | Jingpu Yang | Zirui Song | Lang Gao | Junhong Liang | Zhenhao Chen | Jinghui Zhang | Xiuying Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Recent image generation and editing models demonstrate robust adherence to instructions and high visual quality on academic benchmarks.However, their performance on paid, real-world design projects remains uncertain. We introduce ServImage, a benchmark that explicitly correlates model outputs with economic value in commercial design projects. ServImage consists of (i) ServImageBench: a dataset of 1.07k paid commercial design tasks and 2.05k designer deliverables totaling over $295k, covering portrait, product, and digital content, along with 33k candidate images and 33k human annotations.(ii) ServImageScore: an integrated scoring system that combines three quality dimensions: baseline requirements fulfilment, visual execution quality, and commercial necessity satisfaction. These three dimensions are designed to characterize the factors that drive human payment decisions and indicate whether an image is commercially acceptable.(iii) ServImageModel: under this scoring system, we propose a payment prediction model trained on the human-annotated candidate images, achieving 82.00% accuracy in predicting human payment decisions and producing calibrated payment probabilities.ServImage provides a comprehensive foundation for assessing the commercial viability of image generation models and offers a scalable resource for future research on economically grounded vision systems Github.
When Personalization Tricks Detectors: The Feature-Inversion Trap in Machine-Generated Text Detection
Lang Gao | Xuhui Li | Chenxi Wang | Mingzhe Li | Wei Liu | Zirui Song | Jinghui Zhang | Rui Yan | Preslav Nakov | Xiuying Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Lang Gao | Xuhui Li | Chenxi Wang | Mingzhe Li | Wei Liu | Zirui Song | Jinghui Zhang | Rui Yan | Preslav Nakov | Xiuying Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
As large language models (LLMs) increasingly imitate personal writing styles, personalization has become a key challenge for machine-generated text (MGT) detection. Yet personalized MGT detection remains largely underexplored. In this work, we introduce StyloBench, the first benchmark for evaluating detector robustness under personalization, built from literary and blog texts paired with their LLM-generated imitations. Experiments across diverse detectors show pronounced performance instability under personalization, with frequent inversions relative to general-domain behavior. To better understand this limitation, we conduct an in-depth analysis and attribute it to a feature-inversion trap, i.e., features that are effective for separating human-written text (HWT) from MGT in general flip their effect in personalized contexts, ultimately misleading detectors. Motivated by this, we propose StyloCheck, a diagnostic framework for predicting detector robustness under personalization. StyloCheck identifies the inverted features and quantifies detector dependence using perturbed texts pronounced in the features. In our experiments, StyloCheck predicts both the direction and magnitude of cross-domain performance shifts with an 85% correlation to actual outcomes. We hope this work will raise awareness of the structural risks introduced by personalization and motivate more robust approaches to personalized MGT detection. The code is available at: https://github.com/mbzuai-nlp/Personalized_MGT_Detect
Audio Jailbreak: An Open Comprehensive Benchmark for Jailbreaking Large Audio-Language Models
Zirui Song | Qian Jiang | Mingxuan Cui | Mingzhe Li | Lang Gao | Zeyu Zhang | Zixiang Xu | Yanbo Wang | Guangxian Ouyang | Zhenhao Chen | Xiuying Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Zirui Song | Qian Jiang | Mingxuan Cui | Mingzhe Li | Lang Gao | Zeyu Zhang | Zixiang Xu | Yanbo Wang | Guangxian Ouyang | Zhenhao Chen | Xiuying Chen
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
The rise of Large Audio-Language Models (LAMs) brings both potential and risks, as their audio outputs may contain harmful or unethical content. However, current research lacks a systematic, quantitative evaluation of LAM safety, especially against jailbreak attacks, which are challenging due to the temporal and semantic nature of speech. To bridge this gap, we introduce AJailBench, the first benchmark specifically designed to evaluate jailbreak vulnerabilities in LAMs. We begin by constructing -Base, a dataset of 1,495 adversarial audio prompts spanning 10 policy-violating categories. Using this dataset, we evaluate several state-of-the-art LAMs and reveal that none exhibit consistent robustness across attacks. To further strengthen jailbreak testing and simulate more realistic attack conditions, we propose a method to generate dynamic adversarial variants. Our Audio Perturbation Toolkit (APT) applies targeted distortions across time, frequency, and amplitude domains. To preserve the original jailbreak intent, we enforce a semantic consistency constraint and employ Bayesian optimization to efficiently search for perturbations that are both subtle and highly effective. This results in AJailBench-APT+, an extended dataset of optimized adversarial audio samples. Our findings demonstrate that even small, semantically preserved perturbations can significantly reduce the safety performance of leading LAMs, underscoring the need for more robust and semantically aware defense mechanisms. We release AJailBench to facilitate future research: https://anonymous.4open.science/r/AudioJailbreak-4262/
2025
Under the Shadow of Babel: How Language Shapes Reasoning in LLMs
Chenxi Wang | Yixuan Zhang | Lang Gao | Zixiang Xu | Zirui Song | Yanbo Wang | Xiuying Chen
Findings of the Association for Computational Linguistics: EMNLP 2025
Chenxi Wang | Yixuan Zhang | Lang Gao | Zixiang Xu | Zirui Song | Yanbo Wang | Xiuying Chen
Findings of the Association for Computational Linguistics: EMNLP 2025
Language is not only a tool for communication but also a medium for human cognition and reasoning. If, as linguistic relativity suggests, the structure of language shapes cognitive patterns, then large language models (LLMs) trained on human language may also internalize the habitual logical structures embedded in different languages. To examine this hypothesis, we introduce BICAUSE, a structured bilingual dataset for causal reasoning, which includes semantically aligned Chinese and English samples in both forward and reversed causal forms. Our study reveals three key findings: (1) LLMs exhibit typologically aligned attention patterns, focusing more on causes and sentence-initial connectives in Chinese, while showing a more balanced distribution in English. (2) Models internalize language-specific preferences for causal components order and often rigidly apply them to atypical inputs, leading to degraded performance, especially in Chinese. (3) When causal reasoning succeeds, model representations converge toward semantically aligned abstractions across languages, indicating a shared understanding beyond surface form. Overall, these results suggest that LLMs not only mimic surface linguistic forms but also internalize the reasoning biases shaped by language. Rooted in cognitive linguistic theory, this phenomenon is for the first time empirically verified through structural analysis of model internals.
Word Form Matters: LLMs’ Semantic Reconstruction under Typoglycemia
Chenxi Wang | Tianle Gu | Zhongyu Wei | Lang Gao | Zirui Song | Xiuying Chen
Findings of the Association for Computational Linguistics: ACL 2025
Chenxi Wang | Tianle Gu | Zhongyu Wei | Lang Gao | Zirui Song | Xiuying Chen
Findings of the Association for Computational Linguistics: ACL 2025
Human readers can efficiently comprehend scrambled words, a phenomenon known as Typoglycemia, primarily by relying on word form; if word form alone is insufficient, they further utilize contextual cues for interpretation. While advanced large language models (LLMs) exhibit similar abilities, the underlying mechanisms remain unclear. To investigate this, we conduct controlled experiments to analyze the roles of word form and contextual information in semantic reconstruction and examine LLM attention patterns. Specifically, we first propose SemRecScore, a reliable metric to quantify the degree of semantic reconstruction, and validate its effectiveness. Using this metric, we study how word form and contextual information influence LLMs’ semantic reconstruction ability, identifying word form as the core factor in this process. Furthermore, we analyze how LLMs utilize word form and find that they rely on specialized attention heads to extract and process word form information, with this mechanism remaining stable across varying levels of word scrambling. This distinction between LLMs’ fixed attention patterns primarily focused on word form and human readers’ adaptive strategy in balancing word form and contextual information provides insights into enhancing LLM performance by incorporating human-like, context-aware mechanisms. Code is available on: https://github.com/Aurora-cx/TypoLLM.
Shaping the Safety Boundaries: Understanding and Defending Against Jailbreaks in Large Language Models
Lang Gao | Jiahui Geng | Xiangliang Zhang | Preslav Nakov | Xiuying Chen
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Lang Gao | Jiahui Geng | Xiangliang Zhang | Preslav Nakov | Xiuying Chen
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Jailbreaking in Large Language Models (LLMs) is a major security concern as it can deceive LLMs into generating harmful text. However, understanding of how jailbreaking works remains limited, hindering the development of effective defense strategies. To address this issue, we conduct a large-scale analysis of seven different jailbreak methods and identify that disagreements among methods stem from insufficient observation samples.We introduce the concept of a safety boundary and discover that jailbreaks shift harmful activations outside this boundary, where LLMs become less sensitive to harmful information. Our analysis reveals that low and middle layers play a critical role in these shifts, while deeper layers have a lesser impact.Building on these insights, we propose a novel defense mechanism called Activation Boundary Defense (ABD), which adaptively constrains activations within the safety boundary. To enhance its effectiveness, we use Bayesian optimization to selectively apply the defense to the low and middle layers.Experiments on several benchmark datasets demonstrate that ABD achieves an average Defense Success Rate (DSR) of over 98% against various jailbreak attacks, with less than a 2% impact on the model’s general capabilities.
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- Xiuying Chen 10
- Zirui Song 8
- Chenxi Wang 5
- Zixiang Xu 4
- Mingzhe Li 3
- Yanbo Wang 3
- Jinghui Zhang 3
- Zhenhao Chen 2
- Junhong Liang 2
- Preslav Nakov 2
- Xiangliang Zhang 2
- Rafiq Ali 1
- Bdour Babillie 1
- Xiaojun Chang 1
- Zhaorun Chen 1
- Mingxuan Cui 1
- Qinrong Cui 1
- Nazira Dunbayeva 1
- Jiahui Geng 1
- Tianle Gu 1
- Mingfei Han 1
- Ahmed Heakl 1
- Yuan Huang 1
- Yue Huang 1
- Omar Hussein 1
- Kentaro Inui 1
- Fengxian Ji 1
- Qian Jiang 1
- Salman Khan 1
- Ao Li 1
- Sixian Li 1
- Xuhui Li 1
- Jinghui Liu 1
- Junchang Liu 1
- Wei Liu 1
- Haozhe Luo 1
- Ahmed Mohamed Magdy Mohamed 1
- Youssef Mohamed 1
- Ahmed Nada 1
- Guangxian Ouyang 1
- Wang Pan 1
- Imran Razzak 1
- Yuxia Wang 1
- Zhongyu Wei (魏忠钰) 1
- Rui Yan 1
- Jingpu Yang 1
- Jiayi Ye 1
- Ruihong Zeng 1
- Bairui Zhang 1
- Yixuan Zhang 1
- Zeyu Zhang 1
- Jieyu Zhao 1
- Yue Zhao 1
- Yujun Zhou 1
- Haomin Zhuang 1