Delta-JEPA: Learning Action-Sensitive World Models via Latent Difference Decoding
TLDR
Delta-JEPA learns action-sensitive world models by decoding actions from latent differences, avoiding pixel reconstruction and improving planning in continuous control.
Reasoning
The paper introduces a novel method to prevent action-insensitive representations in world models by supervising latent displacements, which is simple and effective. However, it is only evaluated on simulated continuous-control tasks, lacking real-world validation.
Read-first score
Read-first score 43, weighted from topical fit, citation, graph, method, reproducibility, and recency signals.
Field roles
Rank sensitivity
Stability: volatile; rank range: 330.
Keyword Scores
Deep Analysis
Innovations
- Latent Difference Action Decoder (LDAD) that reconstructs actions from latent displacement between consecutive observations, rather than from concatenated endpoint embeddings.
- Displacement-level supervision that regularizes transition geometry to prevent representation collapse and encourage action-distinguishable latent changes.
- Reconstruction-free world model (Delta-JEPA) that uses only latent prediction and action reconstruction, avoiding pixel reconstruction and distribution-matching regularizers.
Methodology
Delta-JEPA is an end-to-end reconstruction-free world model that combines latent forward prediction with a Latent Difference Action Decoder (LDAD) trained to reconstruct actions from the latent displacement between consecutive observations. It is trained solely with latent prediction and action reconstruction losses, without pixel reconstruction or distribution matching. The model is evaluated on four visual continuous-control tasks against JEPA-based and representation-learning world model baselines, with ablations comparing displacement-based versus endpoint concatenation decoding.
Key Results
Delta-JEPA improves planning performance over JEPA-based and representation-learning world model baselines across four visual continuous-control tasks. Displacement-based action decoding is consistently more effective than endpoint concatenation, and action-sensitivity analyses show clearer action-conditioned latent responses.