Questions in cognitive neuroscience are often framed in terms of correspondences between known types: How is brain state X related to cognitive state Y? What are the correlations or mappings between particular structures and functions? Such framings are well suited for confirmatory testing of coarse-grained hypotheses. They are not necessarily informative, however, for the purpose of exploring finer physical and functional structure. To the contrary, physical states are typically aggregated over anatomical regions of interest, while tasks are designed to optimize one or a few functional contrasts of interest rather than to cover a fuller behavioral or cognitive range.