Abstract
Prior work suggests that complementary white matter pathways within the hippocampus differentially support learning of specific versus general information. In particular, while the trisynaptic pathway (TSP) rapidly forms memories for specific experiences, the monosynaptic pathway (MSP) slowly learns generalities. However, despite the theorized significance of such circuitry, characterizing how information flows within hippocampus (HPC) to support learning in humans remains a challenge. We leveraged diffusion-weighted imaging as a proxy for individual differences in TSP and MSP white matter structure and related it to category learning ability. We hypothesized that learning to categorize the “exception” items that deviated from category rules would benefit from TSP-supported mnemonic specificity. Participant-level estimates of TSP and MSP integrity were constructed from HPC subfield connectomes of white matter streamline density. Consistent with theories of TSP-supported learning mechanisms, we found a specific association between TSP integrity and exception learning. These results highlight the significant role of HPC circuitry in complex human learning.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Conflict of interest: The authors declare no conflicts of interest.