🤖 AI Summary
Anticausal representation learning confronts out-of-distribution (OOD) generalization challenges arising when labels generate features—not vice versa. To address this, we propose the Anticausal Invariant Architecture (ACIA): a measure-theoretic framework that models anticausal generative mechanisms, employing an intervention kernel to uniformly handle both perfect and imperfect interventions—thereby eliminating reliance on explicit causal graphs. ACIA adopts a two-tiered representation architecture: the lower tier captures the label-driven observational generation process, while the upper tier extracts environment-invariant causal patterns, enhanced by invariance regularization and representation disentanglement for robust learning. Theoretically, we derive a tight bound on the OOD generalization performance gap. Empirically, ACIA achieves significant improvements in accuracy and invariance metrics on both synthetic and real-world medical datasets, validating its effectiveness and theoretical guarantees.
📝 Abstract
Causal representation learning in the anti-causal setting (labels cause features rather than the reverse) presents unique challenges requiring specialized approaches. We propose Anti-Causal Invariant Abstractions (ACIA), a novel measure-theoretic framework for anti-causal representation learning. ACIA employs a two-level design, low-level representations capture how labels generate observations, while high-level representations learn stable causal patterns across environment-specific variations. ACIA addresses key limitations of existing approaches by accommodating prefect and imperfect interventions through interventional kernels, eliminating dependency on explicit causal structures, handling high-dimensional data effectively, and providing theoretical guarantees for out-of-distribution generalization. Experiments on synthetic and real-world medical datasets demonstrate that ACIA consistently outperforms state-of-the-art methods in both accuracy and invariance metrics. Furthermore, our theoretical results establish tight bounds on performance gaps between training and unseen environments, confirming the efficacy of our approach for robust anti-causal learning.