NeurIPS 2026 Papers

Motion transfer enables controllable video generation by transferring temporal dynamics from a reference video to synthesize a new video conditioned on a target caption. However, existing Diffusion Transformer (DiT)–based methods are limited to single-object videos, restricting fine-grained control in real-world scenes with multiple objects. In this work, we introduce MotionGrounder, a DiT-based framework that $\textit{firstly}$ handles motion transfer with $\textit{multi-object controllability}$. Our Flow-based Motion Signal (FMS) in MotionGrounder provides a stable motion prior for target video generation, while our Object-Caption Alignment Loss (OCAL) grounds object captions to their corresponding spatial regions. We further propose a $\textit{new}$ Object Grounding Score (OGS), which jointly evaluates (i) spatial alignment between source video objects and their generated counterparts and (ii) semantic consistency between each generated object and its target caption. Our experiments show that MotionGrounder consistently outperforms recent baselines across quantitative, qualitative, and human evaluations.

Detecting AI-generated videos (AIGV) in a generator-agnostic manner is increasingly important as generative models close the gap with real footage, and a video, with many frames, intuitively offers richer forensic evidence than a single image. Yet existing detectors fall short of this expectation: under the encode-then-fuse paradigm, increasing the frame budget from 1 to 8 improves a voting-based image detector by only 5.28%, and even temporal-modeling backbones such as TimeSformer barely improve on this. Per-frame predictions are also noisy: per-frame logits fluctuate substantially within a video and correlate weakly with any frame-level proxy. We trace the cause not to the aggregation step but to per-frame encoding severing multi-frame cues before they can interact, leaving any post-hoc selection, weighting, or aggregation strategy without a reliable basis. We therefore propose **MixForensics**, a blend-then-encode framework that combines multiple frames in the pixel domain into a single composite image (Stochastic Frame Blending, SFB) and regularizes the encoder for consistency across blended views (Blend Invariance Regularization, BIR). To stress-test this approach, we further introduce **MixForensics-Bench**, a test-only benchmark covering ten recent generators (including five closed-source commercial platforms) and two partial-forgery scenarios (temporal splicing and conditional continuation), with matched controls that isolate generative artifacts from editing artifacts. On AIGVDBench and MixForensics-Bench, MixForensics outperforms the strongest baseline by 1.27% and 8.11% on the fully-fake splits, leads on both partial-forgery scenarios by 11.49% on temporal splicing and 9.15% on conditional continuation, and uses fewer encoder forward passes than per-frame methods.

Biological visual systems compute reliably under tight metabolic and wiring constraints despite noisy inputs and stochastic circuit components. Artificial vision systems tend to invert both properties: They consume vastly more energy and can be sensitive to adversarial perturbations. Whether artificial networks with structural properties of real brain wiring are more robust at lower computational cost is unclear. We address this with FlyNet (Lappalainen et al. 2024), a task-optimized, continuous-time neural network model of the fly visual system constrained by its synaptic connectome. We benchmark it against CNN, RAFT (Teed and Deng, 2020), and a sparse continuous-time recurrent neural network without connectome constraints (CTRNN) on a looming-based collision-detection task within a differentiable 3D rendering pipeline. We find that FlyNet is more robust than CNN controls to flicker, unstructured noise, and motion jitter. Compared with RAFT controls, FlyNet is more robust to flicker and motion jitter but less robust to all gradient-based attacks. Yet, FlyNet uses up to five orders of magnitude fewer FLOPs than RAFT, achieving higher robustness on common video corruptions at far lower cost. FlyNet is less robust than CTRNN across all tested perturbations, suggesting that FlyNet's connectome constraints contribute to cost, not robustness. To probe FlyNet's failure modes, we use counterfactual restoration: textures equally far from training as adversarial textures that recover correct classification also recover position and velocity representations, ruling out unfamiliar textures as the cause of failure. Classical reverse-phi illusions degrade the same downstream position and velocity readouts, suggesting that both perturbations may exploit similar computational vulnerabilities. Together, these results show that FlyNet is robust for its computational cost on an ecologically important task, and indicate that different architectures specialized on the same task have specific robustness profiles across perturbation types. Our differentiable pipeline enables computational tests of this hypothesis and generates targeted adversarial stimuli for in vivo experiments.

Out-of-distribution (OOD) detection is essential for deploying machine learning models in high-stakes scientific applications, yet methods that flag OOD inputs without retraining the model have been validated almost exclusively on image classification. We introduce MOOD (Materials Out-of-Distribution Detection), a benchmark for evaluating whether these post-hoc OOD detectors transfer to graph neural networks (GNNs) on materials property prediction. MOOD evaluates 15 post-hoc detectors and 2 supervised diagnostic probes across 4 GNN architectures, 5 MatBench tasks, and 15 physically motivated compositional and structural shifts, yielding over 200 evaluation settings and 4,000 AUROC measurements. Our evaluation reveals three key findings. First, current post-hoc detectors perform near chance; all 15 detectors achieve an AUROC around 0.5. Second, detector failures decompose into two regimes: method bottlenecks and encoder bottlenecks. Method bottlenecks arise when supervised probes can separate in-distribution (ID) from OOD samples but unsupervised detectors fail, meaning that the embeddings contain OOD signal that current detectors do not extract. Encoder bottlenecks arise when even supervised probes fail to separate ID from OOD samples, indicating that the relevant shift is not accessible in the frozen GNN representation. Third, when OOD prediction error exceeds ID error, the AUROC of distance-based and density-based detectors correlates with the size of that gap. Collectively, these findings indicate that reliable OOD detection in scientific domains requires representation learning strategies that explicitly preserve OOD relevant signal, particularly for tasks where current GNN architectures encode no extractable signal at all.

Multimodal large language models (MLLMs) enable prompt-driven image editing, introducing a new challenge for image forgery detection and localization (IFDL). Unlike traditional or mask-guided editing, MLLM-based editing may re-synthesize both tampered and non-tampered regions, weakening the correspondence between tampering regions and pixel-level forensic discrepancies. To study this emerging paradigm, we introduce MLLM-Edit, a large-scale benchmark containing approximately 250k tampered images with pixel-level tampering annotations. MLLM-Edit is constructed through a structured pipeline that combines diverse real-image collection, human-like prompt design, multi-source MLLM-based editing, and semi-automatic mask annotation. Specifically, we collect natural and text images from 30 sources, formulate prompts with target content, tampering type, and consistency constraints, generate forgeries using 18 representative open-source and closed-source MLLM-based editors, and obtain pixel-level tampering masks through a semi-automatic annotation pipeline. We further establish four evaluation protocols covering traditional editing, mask-guided editing, fully synthetic generation, and MLLM-based editing. Experiments show that existing IFDL methods degrade substantially on MLLM-based forgeries, especially in pixel-level localization, highlighting the need for dedicated benchmarks and methods. A demo subset of MLLM-Edit is available at the \href{https://kaggle.com/datasets/8441a4e0594aa02aa7a59ee3eead454410d34716d14423d56a56c7bbbac80655}{project page}.

Multimodal large language models (MLLMs) provide a promising alternative by taking object detection as a sequence generation task. However, applying MLLMs to multimodal object detection poses challenges in visual cross-modal (RGB-Infrared) fusion and coordinate prediction under Cross-Entropy supervision. In this paper, we propose a novel MLLM-based object detection framework that addresses these challenges through improving visual cross-modal token alignment and coordinate generation. Specifically, we formulate RGB-IR fusion as pre-decoding token-space modality routing, implemented by the Cross-Modal Complementary Adapters and the Visual Token-wise Router. We further reformulate coordinate-token learning as scale-adaptive neighborhood likelihood maximization through our proposed Geometry-Aware Loss, bridging discrete token prediction and continuous geometric localization. Extensive experiments show that our method achieves state-of-the-art performance, reaching 67.81\% mAP@0.5 under in-distribution scenarios, outperforming existing baselines by over 8\%, while also exhibiting strong generalization to out-of-distribution and referring object detection tasks.

High-fidelity generative models have narrowed the perceptual gap between synthetic and real images, putting media security under increasing pressure. Most AI-generated image (AIGI) detectors classify by artifact and fail to generalise to new generators. We argue that anchoring detection on the stationary real-image distribution gives a more generalisable signal than chasing the non-stationary forgery distribution, and cast AIGI detection as a Reference-Comparison problem that checks consistency against a learned real-domain feature subspace rather than fitting specific forgery cues. We propose **MIRROR** (**M**anifold **I**deal **R**eference **R**econstruct**OR**), which encodes real-image priors in a learnable discrete memory bank, projects an input onto these prototypes via sparse linear combination to form a manifold-consistent ideal reference, and uses the Comparison Residual and Reconstruction Perplexity as detection signals. To mark the Superhuman Crossover where detectors surpass human experts, we build the Human-AIGI benchmark with a psychophysically curated human-imperceptible subset. Across 14 benchmarks, MIRROR improves over prior methods by 2.1% on six standard benchmarks and 8.1% on seven in-the-wild benchmarks. On Human-AIGI it reaches 89.6% fake accuracy over 27 generators, sitting between the computer-vision-expert and AIGI-detection-expert reference levels, and the gap to the AIGI-detection-expert level closes further as the pretrained backbone scales.

Random forests are widely used in fields involving sensitive tabular data, but existing approaches to enforcing differential privacy (DP) typically degrade performance to the point of impracticality. In this paper, we introduce Lumberjack, a differentially private random forest algorithm that achieves substantially higher utility by constructing large random decision trees and then applying aggressive, privacy-preserving pruning to retain only sufficiently populated nodes. A key component of our approach is a novel $(\varepsilon,\delta)$-DP heavy hitter detection algorithm for hierarchical data, whose error is $O_{\varepsilon,\delta}(\sqrt{\log h})$ for trees of height $h$ and may be of independent interest. This favorable scaling enables the use of significantly deeper trees than in prior work, leading to improved expressiveness under privacy constraints. Our empirical evaluation on benchmark datasets shows that Lumberjack consistently outperforms prior DP random forest methods, establishing a new state of the art. In particular, our approach yields substantial improvements in the privacy-utility trade-off for practical privacy budgets. Our findings suggest that more carefully designed DP random forests can close much of the utility gap, highlighting a promising and underexplored direction for future research.

The ability to reliably distinguish human-written text from that generated by large language models is of profound societal importance. The dominant approach to this problem exploits the likelihood hypothesis: that machine-generated text should appear more probable to a detector language model than human-written text. However, we demonstrate that the token-level signal distinguishing human and machine text is non-uniform across the hidden space of the detector model, and naively averaging likelihood-based token scores across regions with fundamentally different statistical structure, as most detectors do, causes a form of Simpson's paradox: a strong local signal is destroyed by inappropriate aggregation. To correct for this, we introduce a learned local calibration step grounded in Bayesian decision theory. Rather than aggregating raw token scores, we first learn lightweight predictors of the score distributions conditioned on position in hidden space, and aggregate calibrated log-likelihood ratios instead. This single intervention dramatically and consistently improves detection performance across all baseline detectors and all datasets we consider. For example, our calibrated variant of Fast-DetectGPT improves AUROC from $0.63$ to $0.85$ on GPT-5.4 text, and a locally-calibrated DMAP detector we introduce achieves state-of-the-art performance across the board. That said, our central contribution is not a new detector, but a precise diagnosis of a significant cause of under-performance of existing detectors and a principled, modular remedy compatible with any token-averaging pipeline. This will serve as a foundation for the community to build upon, with natural avenues including richer distributional models, improved calibration strategies, and principled ensembling with hidden-space geometry signals via the full Bayes-optimal decision rule.

Deployment-time safety methods for large language models (LLMs) are predominantly supervised and assume access to unsafe training data. Nevertheless, new attacks and harm categories regularly arise, not captured by models trained in such a supervised fashion. An alternative approach is to view this problem through the lens of anomaly detection, namely, to rely solely on modeling safe data and flagging out-of-distribution inputs. However, LLM activations lie in a high-dimensional space, raising concerns about whether anomaly detection is statistically feasible. We show that, under the linear representation hypothesis (LRH), there may indeed be hope. In the LRH concept space, which is typically recovered via a sparse autoencoder (SAE), nearby points share a small common active support. Based on this local sparsity insight, we propose a framework for locally masked SAE-based anomaly detection, and establish a sample complexity bound that scales polynomially in the local sparsity and only \emph{logarithmically} in the SAE's ambient dimension. Finally, we empirically validate our framework on various architectures and datasets, including both capability-testing datasets and safety-specific datasets.

Humanoid robots capable of versatile whole-body interaction with everyday objects represent a central goal of embodied intelligence. Existing approaches often rely on motion-reference inputs or task-specific rewards, coupling policies to particular motion scripts, object geometries, and contact timings. This limits geometric generalization and flexible interaction control, where simple commands specify motion intent while object geometry determines how contact should be executed. We introduce LessMimic, a framework for versatile motion-free-at-inference humanoid–object interaction. At inference, a single whole-body policy is steered by root commands and an interaction-type flag instead of motion-reference inputs, and is conditioned on a compact interaction representation built from short histories of distance-field-derived surface distances and local surface directions. This geometry-conditioned interface enables command-steered control while adapting contact behavior to local object geometry. Through visual distillation, LessMimic further enables egocentric-depth-based deployment for MoCap-free sensing. Across object scales from 0.4× to 1.6×, LessMimic maintains robust performance over four interaction tasks, including PickUp, SitStand, Push, and Carry, where motion-conditioned baselines degrade sharply away from the training scale. Beyond single-task evaluation, LessMimic further supports sequential composition of heterogeneous interaction skills, attaining 62.1% success on five-task sequences and retaining 23.5% success at 15 task instances. By grounding interaction control in local geometry rather than motion references, LessMimic provides a path toward geometry-generalizable, command-steerable humanoid–object control with heterogeneous skill composition.

AI-Generated Image (AIGI) Detection is becoming critical as generative models proliferate, yet existing detectors often generalize poorly by relying on narrow, dataset-specific artifacts. Many prior works improve generalization through additions, such as introducing extra artifact cues, pretraining models, training constraints, or test-time operations, which may increase inference cost and model complexity. In this paper, we take the opposite route and study generalization through subtractions and propose AID--, a plug-and-play framework that improves transformer-based AIGI detectors from both feature and parameter perspectives. At the feature level, we introduce high-order dependency ranking to identify and prune redundant or potentially misleading tokens for progressive token reduction; and at the parameter level, we design relative-advantage head supervision and a class-asymmetric exit rule to train depth-specific early-exit heads. AID-- can be seamlessly integrated into transformer-based AIGI detectors to improve both efficiency and out-of-distribution generalizability, which is experimentally validated on six public datasets. For example, AID-- helps the detector Effort achieve up to a 2.2× speedup while improving generalization accuracy by 3.6% on GenImages.

LLMs are increasingly used not only to generate text from scratch, but also to polish and extend human writing. This makes AI detection a fine-grained problem: downstream users often need to understand the level and form of AI involvement in a text, rather than merely separate human from machine. Existing detectors are poorly suited to this setting because they compress the evidence into scalar scores, selected features, or surface linguistic cues, which miss the subtle patterns left by different forms of AI involvement. We propose ***LensCT***, which makes a frozen LLM's internal predictive behavior visible as a tomogram: an image-like map of how the model responds across tokens and layers. The tomogram captures both temporal patterns along the input sequence and hierarchical patterns across transformer layers, providing a richer view of AI involvement than compressed detector scores. A vision backbone then reads this tomogram to classify the level of AI involvement. On a **237,500**-sample English benchmark spanning five domains and six frontier LLM generators, ***LensCT*** achieves **0.990** in-distribution macro-AUROC, reducing error by **28.6\%** over the strongest baseline. Across **697,500** total evaluation samples, ***LensCT*** consistently outperforms prior detectors under cross-generator, cross-domain, cross-language, and adversarial shifts, showing that temporal-hierarchical tomograms provide a robust and transferable signal for fine-grained AI-involvement detection.

Extremal combinatorics seeks rare mathematical structures that satisfy hard constraints while maximizing a global objective. Most existing neural systems for mathematical discovery train a model to generate complete configurations from scratch. We argue that this framing mismatches the dynamics of effective search: high-quality solutions are more effectively found by preserving a feasible partial core and conditionally regenerating the remaining uncertain objects. We formulate extremal structure discovery as object-level active-core completion: the model is trained to conditionally complete masked objects given a feasible partial core, capturing inter-object relations rather than fitting a distribution over complete configurations. We instantiate this with a full-attention Transformer over object-aligned slots, and propose Inpainting PatternBoost, a variant of PatternBoost. In each iteration, elite constructions from a top pool are partially destroyed by random or structured remasking; the model learns to reconstruct the missing objects, and their completions are reinserted into the pool. We evaluate on the no-three-in-line problem and maximum sum-of-radii circle packing in the unit square, under a single shared abstraction. On no-three-in-line, our framework recovers the optimal $2n$-point configuration for $n$ up to $18$, and reaches $2n-1$ points for $n=19, 20, 25$, outperforming prior neural baselines. On circle packing, where FlowBoost combines neural generation with gradient-based local search, our approach matches or exceeds FlowBoost when paired with the same local search; even without local search, it reaches an average of 88.1% of FlowBoost's reported score across instances.

We present a system for learning generalizable hand-object tracking controllers purely from synthetic data, without requiring any human demonstrations. Our approach makes two key contributions: (1) HOP, a Hand-Object Planner, which can synthesize diverse hand-object trajectories; and (2) HOT, a Hand-Object Tracker that bridges synthetic-to-physical transfer through reinforcement learning and interaction imitation learning, delivering a generalizable controller conditioned on target hand-object states. Our method extends to diverse object shapes and hand morphologies. Through extensive evaluations, we show that our approach enables dexterous hands to track challenging, long-horizon sequences including object re-arrangement and agile in-hand reorientation. These results represent a significant step toward scalable foundation controllers for manipulation that can learn entirely from synthetic data, breaking the data bottleneck that has long constrained progress in dexterous manipulation.

Autoencoders (AEs) are widely used in unsupervised anomaly detection (AD) due to their ability to model complex data distributions. However, their strong reconstruction capacity, while effective for capturing normal patterns, often enables them to also reconstruct anomalous objects, including both individual and collective anomalies, which reduces detection performance. This limitation is particularly severe for collective anomalies, which are frequently misinterpreted as normal clusters. To address this issue, we propose Layer Precision Reduction (LPR), a novel technique that systematically constrains the numerical precision of weights and biases in neural network layers to strategically reduce the learning capacity of neural networks, such as the reconstruction capacity of AEs. LPR encourages the network to prioritize dominant manifold structures while suppressing the reconstruction of rare or anomalous patterns. While LPR was primarily developed for AE-based detectors (the focus of this paper), it is applicable to any neural network. Simulations are conducted with 24 AD models across 30 real-world public datasets. LPR is applied to 10 deep AD models, including 5 unsupervised AE-based methods, 2 unsupervised non-AE-based methods, 1 semi-supervised method, 1 weakly supervised method, and 1 fully supervised method. LPR consistently improves all 10 models, most notably enhancing the best-performing unsupervised AE-based detector from an average AUROC of 72.12\% to 83.06\%, surpassing the strongest unsupervised non-AE-based competitor, which achieves an average AUROC of 77.36\%, across the remaining 14 detectors. These results reveal a previously unexplored link between layer-level numerical precision and manifold pattern prioritization, demonstrating that LPR serves as a simple yet powerful mechanism for enhancing AD performance while offering broad applicability to diverse neural architectures and potential extensions to tasks beyond AD.

We uncover a latent capacity for introspection in a Qwen 32B model, demonstrating that the model can detect when concepts have been injected into its earlier context and identify which concept was injected. While the model denies injection in sampled outputs, logit lens analysis reveals clear detection signals in the residual stream, which are attenuated in the final layers. Furthermore, the effect is heavily dependent on context – e.g., prompting the model with accurate information about AI introspection mechanisms can dramatically strengthen this effect: the sensitivity to injection increases massively (0.3% → 39.9%) with only a 0.6% increase in false positives. Also, mutual information between nine injected and recovered concepts rises from 0.62 bits to 1.05 bits, ruling out generic noise explanations. Our results demonstrate models can have a surprising capacity for introspection and steering awareness that is easy to overlook, with consequences for latent reasoning and safety.

In natural scenes, light sources and occlusions from scene geometry create spatially varying illumination, including brightness gradients, cast shadows, and local color shifts that shape how every object appears. A less explored aspect of diffusion-based object compositing is whether an inserted object can adapt to this local illumination at the desired location. The core challenge to achieve this is the scarcity of large-scale training data capturing how object appearance should adapt to location-dependent illumination. We present LOCO, a data augmentation framework for LOcal light-aware object COmpositing that leverages publicly available monocular videos as illumination sources. We treat each video frame as a virtual spotlight anchored at its camera pose, so that viewpoint variation across a video yields diverse light directions. With controllable beam shape, color, and intensity, this design enables large-scale generation of training data for placement-dependent illumination on the fly. We also introduce LOCO-bench, a benchmark of physically captured composites under spatially varying illumination, where the same object is placed at multiple locations within each scene. Experiments on Laval Indoor SV HDR and LOCO-bench show that LOCO outperforms prior methods in local illumination adaptation while preserving object identity.

Object detection data contains a structural asymmetry that is easy to overlook in dataset distillation (DD). Each detection image couples a spatial layout with a visual realization. Layouts define detection targets through object categories and bounding boxes, while pixels instantiate these targets with particular object appearances and backgrounds. Although both forms can be redundant across a dataset, they play different roles. Layouts define the task distribution, so synthesizing them freely risks altering the detection problem. Visual realizations, on the other hand, are conditional samples attached to layouts. This motivates a separation principle: preserve and recombine layouts from the original data, then use generative priors to diversify their visual realizations. Based on this principle, we propose LCD$^3$, a layout-conditioned diffusion framework for object detection DD. LCD$^3$ constructs composite layouts from diverse groups based on scene-level embeddings. A layout-conditioned diffusion model then generates new images from these layouts, enriching object appearance and scene realization without discarding the spatial structure needed for detection. The generation process is grounded with semantically verified object crops to retain the original visual style. Experiments show that this separation between layout and realization produces more effective distilled detection datasets. LCD$^3$ consistently outperforms the previous state-of-the-art, OD$^3$, across benchmarks using fewer objects per distilled image, e.g., a $12.5$\% mAP50 improvement at a $0.5$\% compression ratio on PASCAL VOC.