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Neurophysiology of sleep and memory consolidation

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​We use high-density scalp EEG, intracranial EEG in epilepsy patients and simultaneous EEG-fMRI to understand the mechanisms of systems consolidation. What are the exact roles of cortical slow oscillations (SOs), thalamocortical spindles and hippocampal ripples during non-REM sleep? What types of memories benefit the most from the precise interaction of these oscillations? How is offline reactivation and replay coordinated in the human brain? Can we bolster memory consolidation via experimental brain stimulation (transcranial electrical stimulation, targeted memory reactivation, closed loop stimulation)?

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Memory transformation across time and sleep

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We combine behavioural experiments, neuroimaging and sleep recordings with AI-based models to understand how memories change as they are consolidated over time.
How does a richly detailed episodic memory gradually become more abstract, gist-like or semantic? Which aspects of a memory are preserved, strengthened or lost during sleep? Can deep neural networks and language models help us quantify these transformations in ways that conventional memory measures cannot? And how are changes in the representational structure of memories related to the neural mechanisms of consolidation during sleep?

Functional neuroanatomy of episodic memory

We use standard (3T) and high-field (7T) functional magnetic resonance imaging (fMRI) as well as direct intracranial recordings from the human hippocampus to understand the division of labour within the MTL in service of episodic memory. What are the roles of the hippocampus and the entorhinal cortex (EC) beyond spatial navigation? Where does domain-specificity seen in MTL cortex turn to domain-generality seen in hippocampus? How does our memory system rapidly switch between encoding and retrieval states?

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Sleep labs

Our research takes place across two sites - the Department of Experimental Psychology, where we have a dedicated sleep lab,  and the Oxford Centre for Human Brain Activity (OHBA), where we have a sleep lab with additional access to a 3T MRI scanner and  MEG/OPM systems.

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