Topic: higher-order structure

Acting judiciously in an environment requires capitalising on the statistical structure underlying observed stimuli. However, structure is expensive to determine and exploit, so efficient learners should focus exclusively on utility-relevant characteristics. To assess this, we administered a pair of related tasks, the first ('learning') required subjects to determine and exploit relevant, and ignore irrelevant, structure to maximize reward; the second ('read-out') quantified their resulting sensitivity to different structure components. Statistical relationships were realised in sampled three-