World Knowledge in the Weights: Reading Concept Circuits of Vision Transformers

Vision transformers (ViTs) have achieved remarkable gen-eralization across visual domains, yet little is known about how theyinternally represent the structure of the world. To address this gap, weuse Cross-Layer Transcoders (CLTs) to read concept circuits from ViTs:directed graphs whose nodes correspond to sparse, interpretable con-cepts and edges capture concept interactions across layers. Our methodyields two complementary views of model behavior. The global conceptcircuit is input-invariant and can be recovered directly from learnedcross-layer weights, exposing the reusable “world knowledge” encodedin the model. The instance concept circuit is input-dependent and iden-tifies the concepts and pathways actually used for a specific prediction,enabling faithful example-level explanations. We demonstrate the util-ity of concept circuits in three ways: (1) Automatic spurious correla-tion discovery: leveraging the statistics of our global concept circuitsto identify shortcut dependencies within the model. (2) Spurious cor-relation removal: intervening on the instance concept circuit to steerthe model towards correct predictions. Empirical results show that ourmethod outperforms existing counterparts by 11.0% on the Waterbirddataset. (3) Model comparison: contrasting the global concept circuits ofdifferent foundation models (e.g., CLIP vs. DINO) to reveal how super-vision paradigms shape representational structure. Our code is availableat https://github.com/deep-real/VisionCLT