Zahra M. Aghajan, Gabriel Kreiman, Itzhak Fried. Periodic Time Cells in Human Entorhinal Cortex. bioRxiv 2022.05.05.490703; doi: https://doi.org/10.1101/2022.05.05.490703

Abstract
“The representation of time in the brain is a fundamental component of cognition. Here we investigated how the human brain represents time during a temporally continuous uninterrupted experience by presenting fifteen neurosurgical patients with an audiovisual video while recording neurons’ activity from multiple brain regions. We report on a set of units that modulate their activity in a strikingly periodic manner across different timescales—from seconds to many minutes. These cells were most prevalent in the entorhinal cortex and time could be decoded from their population activity. Furthermore, these cells remapped their dominant periodicity to shorter timescales during a subsequent recognition memory task. When the audiovisual sequence was presented at two different speeds (regular and faster), a significant percentage of these periodic time cells (PTCs) maintained their timescales, suggesting a degree of invariance with respect to the narrative content. The temporal periodicity of PTCs may complement the spatial periodicity of grid cells, thereby providing scalable spatiotemporal metrics for encoding and retrieval of human experience.”

Zahra M. Aghajan, Gabriel Kreiman, Itzhak Fried. Periodic Time Cells in Human Entorhinal Cortex. bioRxiv 2022.05.05.490703; doi: https://doi.org/10.1101/2022.05.05.490703