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Alex Lamb

21 accepted papers

2026

Improving Sampling for Masked Diffusion Models via Information Gain

ICML 2026poster

Masked Diffusion Models (MDMs) offer greater flexibility in decoding order than autoregressive models but require careful path planning to achieve high-quality generation. While existing samplers typically greedily select positions with the lowest uncertainty, we identify their fundamental limitatio…

Cited by 0SourceScholar
2026

When does predictive inverse dynamics outperform behavior cloning?

ICML 2026poster

Behavior cloning (BC) is a practical offline imitation learning method, but it often fails when expert demonstrations are limited. Recent works have introduced a class of architectures named predictive inverse dynamics models (PIDM) that combine a future state predictor with an inverse dynamics mode…

Cited by 0SourceScholar
2025

The Belief State Transformer

ICLR 2025poster

We introduce the "Belief State Transformer", a next-token predictor that takes both a prefix and suffix as inputs, with a novel objective of predicting both the next token for the prefix and the previous token for the suffix. The Belief State Transformer effectively learns to solve challenging probl…

2025

Towards Improving Exploration through Sibling Augmented GFlowNets

ICLR 2025poster

Exploration is a key factor for the success of an active learning agent, especially when dealing with sparse extrinsic terminal rewards and long trajectories. We introduce Sibling Augmented Generative Flow Networks (SA-GFN), a novel framework designed to enhance exploration and training efficiency o…

Cited by 0SourcePDFScholar
2024

PcLast: Discovering Plannable Continuous Latent States

ICML 2024poster

Goal-conditioned planning benefits from learned low-dimensional representations of rich observations. While compact latent representations typically learned from variational autoencoders or inverse dynamics enable goal-conditioned decision making, they ignore state reachability, hampering their perf…

Cited by 2SourcePDFScholar
2024

Towards Principled Representation Learning from Videos for Reinforcement Learning

ICLR 2024spotlight

We study pre-training representations for decision-making using video data, which is abundantly available for tasks such as game agents and software testing. Even though significant empirical advances have been made on this problem, a theoretical understanding remains absent. We initiate the theoret…

2023

Adaptive Discrete Communication Bottlenecks with Dynamic Vector Quantization for Heterogeneous Representational Coarseness

AAAI 2023technical

Vector Quantization (VQ) is a method for discretizing latent representations and has become a major part of the deep learning toolkit. It has been theoretically and empirically shown that discretization of representations leads to improved generalization, including in reinforcement learning where di…

Cited by 16SourcePDFScholar
2023

Principled Offline RL in the Presence of Rich Exogenous Information

ICML 2023poster

Learning to control an agent from offline data collected in a rich pixel-based visual observation space is vital for real-world applications of reinforcement learning (RL). A major challenge in this setting is the presence of input information that is hard to model and irrelevant to controlling the…

Cited by 4SourcePDFScholar
2023

Representation Learning in Deep RL via Discrete Information Bottleneck

AISTATS 2023poster

Several self-supervised representation learning methods have been proposed for reinforcement learning (RL) with rich observations. For real world applications of RL, recovering underlying latent states is crucial, particularly when sensory inputs can contain irrelevant and exogenous information. In…

Cited by 11SourcePDFScholar
2022

Coordination Among Neural Modules Through a Shared Global Workspace

ICLR 2022oral

Deep learning has seen a movement away from representing examples with a monolithic hidden state towards a richly structured state. For example, Transformers segment by position, and object-centric architectures decompose images into entities. In all these architectures, interactions between differe…

Cited by 108SourcePDFScholar
2022

Discrete Compositional Representations as an Abstraction for Goal Conditioned Reinforcement Learning

NeurIPS 2022accept

Goal-conditioned reinforcement learning (RL) is a promising direction for training agents that are capable of solving multiple tasks and reach a diverse set of objectives. How to \textit{specify} and \textit{ground} these goals in such a way that we can both reliably reach goals during training as…

Cited by 10SourcePDFScholar
2022

Temporal Latent Bottleneck: Synthesis of Fast and Slow Processing Mechanisms in Sequence Learning

NeurIPS 2022accept

Recurrent neural networks have a strong inductive bias towards learning temporally compressed representations, as the entire history of a sequence is represented by a single vector. By contrast, Transformers have little inductive bias towards learning temporally compressed representations, as they…

Cited by 14SourcePDFScholar
2021

Discrete-Valued Neural Communication

NeurIPS 2021poster

Deep learning has advanced from fully connected architectures to structured models organized into components, e.g., the transformer composed of positional elements, modular architectures divided into slots, and graph neural nets made up of nodes. The nature of structured models is that communication…

Cited by 58SourcePDFScholar
2021

Factorizing Declarative and Procedural Knowledge in Structured, Dynamical Environments

ICLR 2021poster

Modeling a structured, dynamic environment like a video game requires keeping track of the objects and their states (declarative knowledge) as well as predicting how objects behave (procedural knowledge). Black-box models with a monolithic hidden state often fail to apply procedural knowledge consis…

Cited by 16SourcePDFScholar
2021

GraphMix: Improved Training of GNNs for Semi-Supervised Learning

AAAI 2021technical

We present GraphMix, a regularization method for Graph Neural Network based semi-supervised object classification, whereby we propose to train a fully-connected network jointly with the graph neural network via parameter sharing and interpolation-based regularization. Further, we provide a theoretic…

2021

Neural Function Modules with Sparse Arguments: A Dynamic Approach to Integrating Information across Layers

AISTATS 2021poster

Feed-forward neural networks consist of a sequence of layers, in which each layer performs some processing on the information from the previous layer. A downside to this approach is that each layer (or module, as multiple modules can operate in parallel) is tasked with processing the entire hidden s…

2021

Recurrent Independent Mechanisms

ICLR 2021spotlight

We explore the hypothesis that learning modular structures which reflect the dynamics of the environment can lead to better generalization and robustness to changes that only affect a few of the underlying causes. We propose Recurrent Independent Mechanisms (RIMs), a new recurrent architecture in wh…

Cited by 389SourcePDFScholar
2020

Learning to Combine Top-Down and Bottom-Up Signals in Recurrent Neural Networks with Attention over Modules

ICML 2020poster

Robust perception relies on both bottom-up and top-down signals. Bottom-up signals consist of what’s directly observed through sensation. Top-down signals consist of beliefs and expectations based on past experience and the current reportable short-term memory, such as how the phrase ‘peanut butter…

2019

Manifold Mixup: Better Representations by Interpolating Hidden States

ICML 2019oral

Deep neural networks excel at learning the training data, but often provide incorrect and confident predictions when evaluated on slightly different test examples. This includes distribution shifts, outliers, and adversarial examples. To address these issues, we propose \manifoldmixup{}, a simple re…

2019

State-Reification Networks: Improving Generalization by Modeling the Distribution of Hidden Representations

ICML 2019oral

Machine learning promises methods that generalize well from finite labeled data. However, the brittleness of existing neural net approaches is revealed by notable failures, such as the existence of adversarial examples that are misclassified despite being nearly identical to a training example, or t…

Cited by 6SourcePDFScholar
2017

Adversarially Learned Inference

ICLR 2017poster

We introduce the adversarially learned inference (ALI) model, which jointly learns a generation network and an inference network using an adversarial process. The generation network maps samples from stochastic latent variables to the data space while the inference network maps training examples in…

Cited by 1907SourcecodeScholar