How is human knowledge organized in the brain to support reasoning?

Much research on human learning has focused on formation and retrieval of simple associations in memory. However, human intelligence also relies on a sophisticated ability to recognize common patterns and reason by analogy. Through computational modeling and neuroimaging, we examine how the brain represents existing knowledge and recognizes common patterns to facilitate reasoning.

Below are summaries and visual abstracts of some of the lab’s recent research. See the full papers for details. A full list of publications, with links to free access on PubMed for most papers, is available on the publications page.

Statistical learning in hippocampus may help discover implicit structure in the world

Hippocampus and precuneus activity patterns reflect an implicit community structure that relates objects and correlate with inference based on community (Pudhiyidath et al. 2022).

Pudhiyidath A, Morton NW, Duran RV, Schapiro AC, Momennejad I, Hinojosa-Rowland DM, Molitor RJ, Preston AR. 2022. Representations of Temporal Community Structure in Hippocampus and Precuneus Predict Inductive Reasoning Decisions. J Cognitive Neurosci. 34:1736–1760.

Cortical networks and hippocampus represent real-world knowledge of famous people and places

Using a model of semantic similarity based on Wikipedia articles, we found that overlapping but distinct networks reflect knowledge of people and places (Morton et al. 2021).

Morton NW, Zippi EL, Noh SM, Preston AR. 2021. Semantic Knowledge of Famous People and Places Is Represented in Hippocampus and Distinct Cortical Networks. J Neurosci. 41:2762–2779.

Memory reactivation simultaneously promotes formation of integrated and differentiated codes in hippocampus

Reactivation of related memories during learning promotes formation of integrated codes in CA1 and differentiated codes in CA2,3/DG, which predict inference (Molitor et al. 2021).

Molitor RJ, Sherrill KR, Morton NW, Miller AA, Preston AR. 2021. Memory Reactivation during Learning Simultaneously Promotes Dentate Gyrus/CA2,3 Pattern Differentiation and CA1 Memory Integration. J Neurosci. 41:726–738.