NeurIPS 2026 Papers

Memory expertise is a learned skill: knowing what to encode, when to retrieve, and how to organize knowledge---a capacity known in cognitive science as metamemory. We bring this perspective to LLMs by treating memory management as a trainable skill. We promote file-system operations to first-class memory actions alongside task actions, letting the model itself decide how to manage its memory. This memory skill improves along two axes: the structure that supports it (prompts, file schemas, action vocabulary), and the proficiency of the model exercising it. Both axes resist manual optimization: episodes in long-horizon tasks run for thousands of steps, and a single memory mistake can hide long before it surfaces, making human review of full trajectories impractical. We introduce AUTOMEM, a framework that automates both axes. In the first loop, a strong LLM reviews complete agent trajectories and iteratively revises the memory structure that shapes how the agent interacts with its memory files. In the second loop, the agent's own good memory decisions are identified from many episodes and used as training signal to sharpen the model's memory proficiency directly. Across three procedurally generated long-horizon games (Crafter, MiniHack, and NetHack), optimizing memory alone---without modifying the model's task-action behavior---improved the base agent's performance 2x--4x, bringing a 32B open-weight model competitive with frontier systems such as Claude Opus 4.5 and Gemini 3.1 Pro. Our results show that memory management is an independently learnable skill, and a high-leverage objective yielding large gains on long-horizon tasks.

The development of embodied models of animal behavior is a major goal of the neuro-AI community. Embodied models will enhance our ability to make direct comparisons between biological and artificial agents. To make such comparisons effective, though, we need embodied models that actually move like animals. Previous work has developed virtual animal bodies and techniques for training realistic motion through imitation. However, to-date, there is no system for embodied animal modeling that produces natural movements both during trained, goal-directed behavior, and during exploration driven by random generation. Here, we introduce Simulated Control via Augmented Motor Priors for Embodied Reinforcement learning (SCAMPER), a system for training an embodied virtual rat model, enabling natural movements during both goal-directed behavior and random exploration. SCAMPER uses a variational architecture with two distinct priors, a motion prior for control and a behavior prior for exploration. We show that combining both of these priors allows SCAMPER to generate realistic behavior during exploration and exploit the task structure effectively. As well, SCAMPER can learn from sparse rewards as a result of the diverse movements induced by the behavior prior, allowing the system to model realistic sparse reward tasks from experimental neuroscience. Altogether, SCAMPER provides the neuro-AI community with an effective new system for training embodied models of rodents on realistic tasks.

The evolution of mathematics is shaped importantly by interestingness: researchers choose which problems to pursue, and students choose which problems to engage with, based on expectations of interest and challenge. As AI systems, particularly large language models (LLMs) that operate flexibly over natural language and formal mathematics, are increasingly used in mathematics research and education, it becomes crucial to characterize how closely their judgments align with people from different mathematical backgrounds. We study whether LLMs align with human interestingness judgments by comparing LLM ratings with those of two populations, crowdsourced participants with college math experience and International Math Olympiad competitors. Although many LLMs broadly agree with human notions of interestingness, they largely fail to match the distribution of human judgments. They also weakly align with why humans find problems interesting, with low correlation to human-selected rationales. Finally, we evaluate LLMs’ ability to generate interesting problems and find that, after filtering for validity, LLMs are able to generate engaging problems. We conclude with takeaways, including the need for multi-LLM human-AI collaborative systems, that highlight both the promise and current limits of LLMs as partners in mathematical reasoning.

Temporal sequences in working memory are hierarchically organized to support flexible behavior. Recent neural recordings suggest that this organization relies on a 1D-to-2D neural geometrical folding in working memory, whereby ordinal positions are re-encoded within an orthogonal scaffold, with two dimensions indexing global (chunk-level rank) and local ranks (within-chunk position), respectively. This findings implicate an important structural principle for memory, yet the computational mechanisms underlying this geometry remain unclear. Here, we study this question using a recurrent neural network with fast Hebbian plasticity (Hebb-RNN). When meta-trained on rank recalling tasks, the Hebb-RNN generalizes to novel item–rank bindings and hierarchical sequences, outperforming control models. Mechanistic analysis reveals that the network develops an orthogonal ordinal geometry consistent with empirical findings. This geometry transforms temporal inputs into abstract ordinal ranks that provide a memory scaffold, while Hebbian plasticity supports rapid conjunctive binding of item content to this structure. Furthermore, the pre-learned geometric scaffold significantly accelerates learning in novel tasks, supporting efficient transfer. By incorporating a predictive module, our model extends to real-world encodings and acquires hierarchical geometry without explicit chunking signals. Together, our results provide a biologically plausible framework for hierarchical sequence representation, offering new insights into structured memory organization for both neuroscience and machine learning.

We study connections between the sample cost of replicability, which requires an algorithm to produce consistent outputs in different runs, and the sample complexity in the high success probability regime for distribution testing algorithms. Specifically, we consider a stronger notion of replicability, which we term as strong replicability, and show that any $\rho$-strongly-replicable testing algorithm can be converted in a blackbox manner to a tester with at most $\exp(-\tilde{\Omega}(\rho^{-2}))$ failure probability under the same sample budget. Our conversion is optimal for many natural testers. As applications of our conversion theorem, we obtain tight sample lower bounds for strongly replicable testers for coin bias and closeness testing.

Systematicity is the capacity to generalize compositionally. Existing benchmarks primarily test behavioral systematicity, while representation-level analyses often leave open whether recovered signals are merely decodable or causally used during generation. We therefore introduce $\mathrm{Bounded\mbox{-}RS}$, an evaluation artifact and protocol for adjudicating these possibilities under bounded hypotheses: unsupported, present-only, causal-use, or underdetermined. The artifact is a controlled semantic-parsing setting with matched recombination tests, exact intervention pairs, and evidence routines for recoverability, interchange, necessity, and repair during generation. We apply $\mathrm{Bounded\mbox{-}RS}$ to the two prominent representation-level explanations of systematic generalization, binding and geometry. Within the family instantiations evaluated here, and under the same behavioral anchor and state semantics, the binding family satisfies the criteria for $\mathit{Causal\mbox{-}use}$, whereas the geometry family is adjudicated as $\mathit{Unsupported}$ under its frozen closure basis. Detector-truthfulness tests do not validate a geometry detector, so the geometry conclusion remains a claim about the tested family rather than about all possible geometric mechanisms. $\mathrm{Bounded\mbox{-}RS}$ thus provides a reusable way to make disciplined representational claims from behavioral systematicity tests.