Stress disrupts hippocampal integration of overlapping events and memory inference in humans.
Level 2 - randomized trial
Controlled human experimental trial comparing stress versus control manipulation on neuroimaging and memory outcomes.
PubMed 42172327 · doi:10.1126/sciadv.aea5496
What was done
Adults learned initial A-B associations on day 1 and were assigned to either an acute stress or control manipulation before learning overlapping B-C associations on day 2. Subsequent memory inference across the overlapping pairs (A-C) was tested. Hippocampal reactivation of A elements during B-C learning and neural representational overlap between A and C elements were measured using representational similarity analysis.
What was found
The abstract reports directional and correlational outcomes without specific numerical values or effect sizes. Acute stress reduced hippocampal reactivation of prior A elements during B-C learning, with lower reactivation directly correlating with impaired A-C inference. Additionally, stress increased neural dissimilarity between overlapping A and C representations in the hippocampus, reflecting pattern differentiation into discrete events rather than integrative encoding.
Why it matters
These findings identify a neural mechanism by which acute stress prevents the integration of related information in the hippocampus, impairing the ability to make novel cognitive inferences.
Limits
The abstract does not state the sample size, participant demographics, the nature of the stress manipulation, or numerical statistics. The study evaluates acute laboratory stress in a controlled setting, which may not fully represent chronic stress or naturalistic learning environments.
Cited by
- supports Acute stress impairs the brain's ability to form insightful connections between previously stored memories or paired associations.