WIP: Ripple-driven Sequential Replay of Memory during Sleep
Pin-Chun Chen
WIN Wednesday
Wednesday, 31 January 2024, 12pm to 1pm
Hybrid via Teams and in the Cowey Room, WIN Annexe
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Ripple-driven Sequential Replay of Memory during Sleep
Presented by Pin-Chun Chen
Authors: Pin-Chun Chen & Bernhard Staresina
Abstract: One of the important functions of sleep is stabilising (‘consolidating’) new memories. However, the mechanisms by which the human brain processes newly acquired information during sleep are not yet fully understood. Animal work has demonstrated that hippocampal ripples coordinate memory reactivations with an array of cortical regions. However, the whole-brain temporal dynamics of these coordinated reactivations preceding and following hippocampal ripples remain obscure, largely due to limited spatiotemporal resolution of whole-brain neuroimaging techniques in capturing ripple-mediated memory reactivations. Scalp EEG suffers from relatively poor spatial resolution and is insensitive to high-frequency oscillations. Likewise, hemodynamic signals are too slow to capture rapid temporal dynamics between different areas related to ripples. Despite the superior temporal and spatial specificity that intracranial EEG offers, invasive recordings suffer from scarcity and heterogeneity of electrode coverage across participants and thus preclude systematic assessment of hippocampal interactions with cortical areas. Excitingly though, Magnetoencephalography (MEG) is well-suited to overcome these limitations and to characterise ripples alongside the whole-brain dynamics of memory reactivations.Therefore, we aim to better understand how episodic memories are consolidated during sleep by utilising simultaneous MEG-EEG recording during overnight sleep.