Sequential replay of nonspatial task states in the human hippocampus

• Published in: Science (American Association for the Advancement of Science) Vol. 364; no. 6447
• Main Authors: Schuck, Nicolas W, Niv, Yael
• Format: Journal Article
• Language: English
• Published: United States The American Association for the Advancement of Science 28-06-2019
• Subjects: Activation; Activity patterns; Brain; Brain mapping; Computational neuroscience; Computer simulation; Decision Making; Decoding; Feasibility; Feasibility studies; Female; Functional magnetic resonance imaging; Hippocampus; Hippocampus - physiology; Human performance; Humans; Investigations; Learning algorithms; Machine learning; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medical imaging; Memory; Mental task performance; Multivariate analysis; Navigation; Navigation behavior; Neuroimaging; Neuroimaging - methods; Neurology; NMR; Nuclear magnetic resonance; Permutations; Representations; Resonance; Rest; Rest - physiology; Rodents; Sensory Experience; Sequences; Sleep; Somatosensory cortex; Spatial memory; Statistical analysis; Support vector machines; Task complexity; Temporal cortex; Temporal resolution; Young Adult
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aaw5181

Sequential neural activity patterns related to spatial experiences are "replayed" in the hippocampus of rodents during rest. We investigated whether replay of nonspatial sequences can be detected noninvasively in the human hippocampus. Participants underwent functional magnetic resonance imaging (fMRI) while resting after performing a decision-making task with sequential structure. Hippocampal fMRI patterns recorded at rest reflected sequentiality of previously experienced task states, with consecutive patterns corresponding to nearby states. Hippocampal sequentiality correlated with the fidelity of task representations recorded in the orbitofrontal cortex during decision-making, which were themselves related to better task performance. Our findings suggest that hippocampal replay may be important for building representations of complex, abstract tasks elsewhere in the brain and establish feasibility of investigating fast replay signals with fMRI.