Publications

Intelligent Switching for Reset-Free RL

Darshan Patil

Janarthanan Rajendran

In the real world, the strong episode resetting mechanisms that are needed to train agents in simulation are unavailable. The \textit{resett… (see more)ing} assumption limits the potential of reinforcement learning in the real world, as providing resets to an agent usually requires the creation of additional handcrafted mechanisms or human interventions. Recent work aims to train agents (\textit{forward}) with learned resets by constructing a second (\textit{backward}) agent that returns the forward agent to the initial state. We find that the termination and timing of the transitions between these two agents are crucial for algorithm success. With this in mind, we create a new algorithm, Reset Free RL with Intelligently Switching Controller (RISC) which intelligently switches between the two agents based on the agent's confidence in achieving its current goal. Our new method achieves state-of-the-art performance on several challenging environments for reset-free RL.

2024-01-16

ICLR.cc/2024/Conference (poster)

doi.org

openreview.net

Intelligent Switching for Reset-Free RL

Darshan Patil

Janarthanan Rajendran

Glen Berseth

Sarath Chandar

2024-01-16

ICLR.cc/2024/Conference (poster)

openreview.net

Jointly-Learned Exit and Inference for a Dynamic Neural Network

Florence Regol

Joud Chataoui

Mark Coates

2024-01-16

ICLR.cc/2024/Conference (poster)

openreview.net

Large Language Models as Generalizable Policies for Embodied Tasks

Andrew Szot

Max Schwarzer

Harsh Agrawal

Bogdan Mazoure

Walter Talbott

Rin Metcalf

Natalie Mackraz

(Rex) Devon Hjelm

Alexander T Toshev

2024-01-16

ICLR.cc/2024/Conference (poster)

doi.org

openreview.net

Leveraging Unpaired Data for Vision-Language Generative Models via Cycle Consistency

Tianhong Li

Sangnie Bhardwaj

Yonglong Tian

Han Zhang

Jarred Barber

Dina Katabi

Guillaume Lajoie

Huiwen Chang

Dilip Krishnan

Current vision-language generative models rely on expansive corpora of paired image-text data to attain optimal performance and generalizati… (see more)on capabilities. However, automatically collecting such data (e.g. via large-scale web scraping) leads to low quality and poor image-text correlation, while human annotation is more accurate but requires significant manual effort and expense. We introduce

2024-01-16

ICLR.cc/2024/Conference (spotlight)

doi.org

openreview.net

Local Search GFlowNets

Minsu Kim

Taeyoung Yun

Emmanuel Bengio

Dinghuai Zhang

Yoshua Bengio

Sungsoo Ahn

Jinkyoo Park

Generative Flow Networks (GFlowNets) are amortized sampling methods that learn a distribution over discrete objects proportional to their re… (see more)wards. GFlowNets exhibit a remarkable ability to generate diverse samples, yet occasionally struggle to consistently produce samples with high rewards due to over-exploration on wide sample space. This paper proposes to train GFlowNets with local search, which focuses on exploiting high-rewarded sample space to resolve this issue. Our main idea is to explore the local neighborhood via backtracking and reconstruction guided by backward and forward policies, respectively. This allows biasing the samples toward high-reward solutions, which is not possible for a typical GFlowNet solution generation scheme, which uses the forward policy to generate the solution from scratch. Extensive experiments demonstrate a remarkable performance improvement in several biochemical tasks. Source code is available: https://github.com/dbsxodud-11/ls_gfn.

2024-01-16

ICLR.cc/2024/Conference (spotlight)

openreview.net

LOQA: Learning with Opponent Q-Learning Awareness

Milad Aghajohari

Juan Agustin Duque

Tim Cooijmans

Aaron Courville

In various real-world scenarios, interactions among agents often resemble the dynamics of general-sum games, where each agent strives to opt… (see more)imize its own utility. Despite the ubiquitous relevance of such settings, decentralized machine learning algorithms have struggled to find equilibria that maximize individual utility while preserving social welfare. In this paper we introduce Learning with Opponent Q-Learning Awareness (LOQA) , a novel reinforcement learning algorithm tailored to optimizing an agent's individual utility while fostering cooperation among adversaries in partially competitive environments. LOQA assumes that each agent samples actions proportionally to their action-value function Q. Experimental results demonstrate the effectiveness of LOQA at achieving state-of-the-art performance in benchmark scenarios such as the Iterated Prisoner's Dilemma and the Coin Game. LOQA achieves these outcomes with a significantly reduced computational footprint compared to previous works, making it a promising approach for practical multi-agent applications.

2024-01-16

ICLR.cc/2024/Conference (poster)

openreview.net

Mastering Memory Tasks with World Models

Mohammad Reza Samsami

Artem Zholus

Janarthanan Rajendran

Sarath Chandar

Current model-based reinforcement learning (MBRL) agents struggle with long-term dependencies. This limits their ability to effectively solv… (see more)e tasks involving extended time gaps between actions and outcomes, or tasks demanding the recalling of distant observations to inform current actions. To improve temporal coherence, we integrate a new family of state space models (SSMs) in world models of MBRL agents to present a new method, Recall to Imagine (R2I). This integration aims to enhance both long-term memory and long-horizon credit assignment. Through a diverse set of illustrative tasks, we systematically demonstrate that R2I not only establishes a new state-of-the-art for challenging memory and credit assignment RL tasks, such as BSuite and POPGym, but also showcases superhuman performance in the complex memory domain of Memory Maze. At the same time, it upholds comparable performance in classic RL tasks, such as Atari and DMC, suggesting the generality of our method. We also show that R2I is faster than the state-of-the-art MBRL method, DreamerV3, resulting in faster wall-time convergence.

2024-01-16

ICLR.cc/2024/Conference (oral)

doi.org

openreview.net

Mechanistically analyzing the effects of fine-tuning on procedurally defined tasks

Samyak Jain

Robert Kirk

Ekdeep Singh Lubana

Robert P. Dick

Hidenori Tanaka

Tim Rocktäschel

Edward Grefenstette

David Scott Krueger

Fine-tuning large pre-trained models has become the de facto strategy for developing both task-specific and general-purpose machine learning… (see more) systems, including developing models that are safe to deploy. Despite its clear importance, there has been minimal work that explains how fine-tuning alters the underlying capabilities learned by a model during pretraining: does fine-tuning yield entirely novel capabilities or does it just modulate existing ones? We address this question empirically in synthetic, controlled settings where we can use mechanistic interpretability tools (e.g., network pruning and probing) to understand how the model's underlying capabilities are changing. We perform an extensive analysis of the effects of fine-tuning in these settings, and show that: (i) fine-tuning rarely alters the underlying model capabilities; (ii) a minimal transformation, which we call a `wrapper', is typically learned on top of the underlying model capabilities, creating the illusion that they have been modified; and (iii) further fine-tuning on a task where such ``wrapped capabilities'' are relevant leads to sample-efficient revival of the capability, i.e., the model begins reusing these capabilities after only a few gradient steps. This indicates that practitioners can unintentionally remove a model's safety wrapper merely by fine-tuning it on a, e.g., superficially unrelated, downstream task. We additionally perform analysis on language models trained on the TinyStories dataset to support our claims in a more realistic setup.

2024-01-16

ICLR.cc/2024/Conference (poster)

openreview.net

Motif: Intrinsic Motivation from Artificial Intelligence Feedback

Martin Klissarov

Pierluca D'Oro

Shagun Sodhani

Roberta Raileanu

Pierre-Luc Bacon

Pascal Vincent

Amy Zhang

Mikael Henaff

Exploring rich environments and evaluating one's actions without prior knowledge is immensely challenging. In this paper, we propose Motif, … (see more)a general method to interface such prior knowledge from a Large Language Model (LLM) with an agent. Motif is based on the idea of grounding LLMs for decision-making without requiring them to interact with the environment: it elicits preferences from an LLM over pairs of captions to construct an intrinsic reward, which is then used to train agents with reinforcement learning. We evaluate Motif's performance and behavior on the challenging, open-ended and procedurally-generated NetHack game. Surprisingly, by only learning to maximize its intrinsic reward, Motif achieves a higher game score than an algorithm directly trained to maximize the score itself. When combining Motif's intrinsic reward with the environment reward, our method significantly outperforms existing approaches and makes progress on tasks where no advancements have ever been made without demonstrations. Finally, we show that Motif mostly generates intuitive human-aligned behaviors which can be steered easily through prompt modifications, while scaling well with the LLM size and the amount of information given in the prompt.

2024-01-16

ICLR.cc/2024/Conference (poster)

doi.org

openreview.net

Object centric architectures enable efficient causal representation learning

Amin Mansouri

Jason Hartford

Yan Zhang

Yoshua Bengio

Causal representation learning has showed a variety of settings in which we can disentangle latent variables with identifiability guarantees… (see more) (up to some reasonable equivalence class). Common to all of these approaches is the assumption that (1) the latent variables are represented as

2024-01-16

ICLR.cc/2024/Conference (poster)

doi.org

openreview.net

PhyloGFN: Phylogenetic inference with generative flow networks

Ming Yang Zhou

Zichao Yan

Elliot Layne

Nikolay Malkin

Dinghuai Zhang

Moksh J. Jain

Mathieu Blanchette