Masking evidence gives modular systems a striking compositional edge
A preregistered study across 60 four-cell systems found that restricting modules from seeing foreign evidence sharply improved held-out two- and three-step composition, with median accuracy gains of 0.846 and 0.859. Every one of 12 preregistered comparisons cleared its margin, but the result is narrower than the headline: globally visible systems failed the marker-following check, and the audits do not prove masking caused the intermediate computations. The protocols, checkpoints, and results are public.