A neural code for time and space in the human brain

• Published in: Cell reports (Cambridge) Vol. 42; no. 11; p. 113238
• Main Authors: Schonhaut, Daniel R., Aghajan, Zahra M., Kahana, Michael J., Fried, Itzhak
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 28.11.2023; Elsevier
• Subjects: Brain - physiology; CP: Neuroscience; hippocampus; Hippocampus - physiology; human neurons; Humans; medial temporal lobe; memory; Neurons - physiology; prefrontal cortex; Space Perception - physiology; time; virtual navigation; medial temporal lobe; virtual navigation; memory; human neurons; hippocampus; CP: Neuroscience; prefrontal cortex; time
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2023.113238

Time and space are primary dimensions of human experience. Separate lines of investigation have identified neural correlates of time and space, yet little is known about how these representations converge during self-guided experience. Here, 10 subjects with intracranially implanted microelectrodes play a timed, virtual navigation game featuring object search and retrieval tasks separated by fixed delays. Time cells and place cells activate in parallel during timed navigation intervals, whereas a separate time cell sequence spans inter-task delays. The prevalence, firing rates, and behavioral coding strengths of time cells and place cells are indistinguishable—yet time cells selectively remap between search and retrieval tasks, while place cell responses remain stable. Thus, the brain can represent time and space as overlapping but dissociable dimensions. Time cells and place cells may constitute a biological basis for the cognitive map of spatiotemporal context onto which memories are written. [Display omitted] •Human medial temporal lobe and prefrontal cortex neurons encode time during task-free delays•Time and place are independently represented during timed navigation•Time cells remap between contextually similar events with stable place cell firing•Population neural activity represents time across multiple events in a sequence Schonhaut et al. record direct neural firing while subjects play a timed, virtual navigation game with object search and retrieval tasks separated by fixed delays. The authors find that neural codes for time and space are simultaneously active, context-specific, and dissociable, providing a putative mechanism for representing spatiotemporal context.