Martin Takáč
Author directoryOther people with similar names: Martin Takac
2026
Temporal Contrastive Decoding: A Training-Free Method for Large Audio-Language Models
Yanda Li | Yuhan Liu | Zirui Song | Yunchao Wei | Martin Takáč | Salem Lahlou
Findings of the Association for Computational Linguistics: ACL 2026
Yanda Li | Yuhan Liu | Zirui Song | Yunchao Wei | Martin Takáč | Salem Lahlou
Findings of the Association for Computational Linguistics: ACL 2026
Large audio-language models (LALMs) generalize across speech, sound, and music, but unified decoders can exhibit a temporal smoothing bias: transient acoustic cues may be underutilized in favor of temporally smooth context that is better supported by language priors, leading to less specific audio-grounded outputs. We propose Temporal Contrastive Decoding (TCD), a training-free decoding method for unified LALMs that mitigates this effect at inference time. TCD constructs a temporally blurred slow-path view by smoothing the input waveform and re-encoding it, then contrasts next-token logits from the original and slow-path views. The contrastive signal is applied as a token-level logit update restricted to a small candidate set. A self-normalized stability score sets the blur window and update scale, and a step-wise gate based on uncertainty and audio reliance activates the update only when needed. Experiments on MMAU and AIR-Bench show consistent improvements on strong unified LALMs. We further conduct ablations and an architectural applicability study to analyze the contributions of key components and how TCD behaves across large audio-language model designs.
CopyShield: A Cross-Level Benchmark of Copyright Defenses in LLMs
Maryam Alshehyari | Dushyant Singh Chauhan | Samuele Poppi | Martin Takáč | Salem Lahlou | Nils Lukas
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Maryam Alshehyari | Dushyant Singh Chauhan | Samuele Poppi | Martin Takáč | Salem Lahlou | Nils Lukas
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models can reproduce memorized text verbatim, yet copyright defenses are usually evaluated under incompatible protocols. We introduce CopyShield, a controlled benchmark comparing three representative defenses at distinct intervention levels: contrastive decoding (output), Direct Preference Optimization (behavioral), and activation intervention (representation). We evaluate CopyShield on two model families, LLaMA-3.1-8B and Mistral-7B-v0.3, using controlled memorization over five public-domain books and a shared protocol measuring literal leakage, calibrated non-literal leakage, utility, and degeneracy. Across these methods, intervention level is associated with distinct compliance–utility trade-offs. On LLaMA-3.1-8B, contrastive decoding remains near-degeneracy-free (0–2%) but reaches a literal-suppression floor at NV-Recall 0.192–0.203. DPO nearly eliminates literal leakage (0.263 to 0.002) but induces paraphrase-loop degeneracy in 58% of QA outputs, with no utility gain over the SFT baseline. Activation intervention attains the lowest non-literal flagging rate (1/200) by blocking 84% of non-literal queries before generation. Human evaluation confirms that DPO has low coherence, whereas activation lowers perceived copyright risk through broad refusal. On Mistral-7B-v0.3, the output- and representation-level patterns persist, while DPO degeneracy falls to 10–14%, showing that its severity is model-dependent. Together, CopyShield provides cross-level reference baselines and identifies targeted non-literal suppression as an open challenge. The code is available at https://github.com/spotai-mbzuai/CopyShield.git.
2025
Library-Like Behavior In Language Models is Enhanced by Self-Referencing Causal Cycles
Munachiso S Nwadike | Zangir Iklassov | Toluwani Aremu | Tatsuya Hiraoka | Benjamin Heinzerling | Velibor Bojkovic | Hilal AlQuabeh | Martin Takáč | Kentaro Inui
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Munachiso S Nwadike | Zangir Iklassov | Toluwani Aremu | Tatsuya Hiraoka | Benjamin Heinzerling | Velibor Bojkovic | Hilal AlQuabeh | Martin Takáč | Kentaro Inui
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
We introduce the concept of the self-referencing causal cycle (abbreviated ReCall )—a mechanism that enables large language models (LLMs) to bypass the limitations of unidirectional causality, which underlies a phenomenon known as the reversal curse. When an LLM is prompted with sequential data, it often fails to recall preceding context. For example, when we ask an LLM to recall the line preceding “O say does that star-spangled banner yet wave” in the U.S. National Anthem, it often fails to correctly return “Gave proof through the night that our flag was still there”—this is due to the reversal curse. It occurs because language models such as ChatGPT and Llama generate text based on preceding tokens, requiring facts to be learned and reproduced in a consistent token order. While the reversal curse is often viewed as a limitation, we offer evidence of an alternative view: it is not always an obstacle in practice. We find that ReCall is driven by what we designate as cycle tokens—sequences that connect different parts of the training data, enabling recall of preceding tokens from succeeding ones. Through rigorous probabilistic formalization and controlled experiments, we demonstrate how the cycles they induce influence a model’s ability to reproduce information. To facilitate reproducibility, we provide our code and experimental details at https://anonymous.4open.science/r/remember-B0B8/.