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Oral Session

Oral Session 2

Grand Ballroom
Tue 6 Oct 3:30 p.m. PDT — 4:30 p.m. PDT
Abstract:
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Tue 6 Oct. 15:30 - 15:45 PDT

A Unified View of Attention and Residual Sinks: Outlier-Driven Rescaling is Essential for Large Language Model Training

Zihan Qiu ⋅ Zeyu Huang ⋅ Kaiyue Wen ⋅ Peng Jin ⋅ Bo Zheng ⋅ Yuxin Zhou ⋅ Haofeng Huang ⋅ Zekun Wang ⋅ Xiao Li ⋅ Huaqing Zhang ⋅ Yang Xu ⋅ Haoran Lian ⋅ Siqi Zhang ⋅ Rui Men ⋅ jianwei zhang ⋅ Ivan Titov ⋅ Dayiheng Liu ⋅ Jingren Zhou ⋅ Junyang Lin

We investigate the functional role of emergent outliers in large language models, specifically attention sinks (a few tokens that consistently receive large attention logits) and residual sinks (a few fixed dimensions with persistently large activations across most tokens). We hypothesize that these outliers, in conjunction with the corresponding normalizations (\textit{e.g.}, softmax attention and RMSNorm), effectively rescale other non-outlier components. We term this phenomenon \textit{outlier-driven rescaling} and validate this hypothesis across different model architectures and training token counts. This view unifies the origin and mitigation of both sink types. Our main conclusions and observations include: (1) Outliers function jointly with normalization: removing normalization eliminates the corresponding outliers but degrades training stability and performance; directly clipping outliers while retaining normalization leads to degradation, indicating that outlier-driven rescaling contributes to training stability. (2) Outliers serve more as rescale factors rather than contributors, as the final contributions of attention and residual sinks are significantly smaller than those of non-outliers. (3) Outliers can be absorbed into parameters or reduced by explicit gated rescaling, which in turn yield better training and quantization performance.

We study the internal mechanisms that govern when LLMs choose to retract wrong answers, i.e., spontaneously and immediately acknowledge errors in their previously generated false assertions. Using model-specific testbeds, we find that while LLMs are capable of retraction, they do so only rarely, even when they can recognize their mistakes when asked in a separate interaction. We identify a reliable predictor of retraction: the model's \emph{momentary belief}, as measured by a linear probe on its internal representation. The probe is trained to predict the correctness of answers on external datasets unrelated to retraction, then applied to settings where models should retract. A model retracts only when it ``believes'' its answers to be incorrect \emph{during generation}; these beliefs frequently diverge from models' parametric knowledge as measured by factoid questions. Steering experiments further demonstrate that model belief causally drives retraction. In particular, when the model believes its answer to be incorrect, this not only encourages the model to attempt further verification, but also alters attention dynamics to promote retraction. Finally, we show that supervised fine-tuning re-uses this existing mechanism linking belief with retraction, and primarily improves retraction performance by helping the model learn more accurate internal beliefs.

Tue 6 Oct. 16:00 - 16:15 PDT

Phonological Perception of Sign Language Models

Kayo Yin ⋅ Jessica Carter ⋅ Alex X Lu ⋅ Annemarie Kocab

Sign languages are compositional systems where meaning arises by combining sublexical phonological parameters, such as handshape, location, and movement. While deep learning models for Sign Language Recognition (SLR) have achieved increased performance on translation benchmarks, it remains unclear whether these models distinguish abstract phonological features or merely rely on low-level statistical correlations. This work evaluates the phonological perception of SLR models by probing phonological sensitivity using minimal pairs and evaluating representational alignment with human behavioral data. Our results reveal that SLR models exhibit emergent phonological sensitivity, but with clear architectural trade-offs: pose-based models are sensitive to handshape contrasts, while pixel-based models better capture location changes. Furthermore, pose-based models learn latent representations that correlates with human perceptual similarity judgments (r ≈ 0.51). These findings suggest that while SLR models exhibit emergent phonology, current training paradigms are insufficient to scale them beyond their architectural inductive biases.

Tue 6 Oct. 16:15 - 16:30 PDT

Attribution Bias in Large Language Models

Eliza H Berman ⋅ Bella Chang ⋅ Daniel B Neill ⋅ Emily Black

As Large Language Models (LLMs) are increasingly used to support search and information retrieval, it is critical that they accurately attribute content to its original authors. In this work, we introduce \textsc{AttriBench}, the first fame- and demographically-balanced quote attribution benchmark dataset. Through explicitly balancing author fame and demographics, \textsc{AttriBench} enables controlled investigation of demographic bias in quote attribution. Using this dataset, we evaluate 11 widely used LLMs across different prompt settings and find that quote attribution remains a challenging task even for frontier models. We observe large and systematic disparities in attribution accuracy between race, gender, and intersectional groups. We further introduce and investigate \textit{suppression}, a distinct failure mode in which models omit attribution entirely, even when the model has access to authorship information. We find that suppression is widespread and unevenly distributed across demographic groups, revealing systematic biases not captured by standard accuracy metrics. Our results position quote attribution as a benchmark for representational fairness in LLMs.