FOR 5434:  Information Abstraction During Sleep

• Subject Area: Medicine ; Social and Behavioural Sciences
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 468645090

Sleep is not an idle state. Instead, the organism continues to process information that has been encoded during prior wakefulness. During waking, the organism takes up huge amounts of information, much more than can be kept for the long term. We assume that information processing in the “off-line” condition of sleep serves to reduce this information load by abstracting “gist” information, with only this gist information becoming stored in long-term memory. Gist might represent invariant information repeating across experiences or salient information, e.g., a danger signal, that is unique to a specific experience. The main goals of the planned Research Unit are to characterize what the gist is that is stored for the long-term, and how it is abstracted during sleep. We address these questions in the framework of the “active systems consolidation” concept of sleep-dependent memory processing, assuming that consolidation processes during sleep specifically pertain to the hippocampus-dependent episodic memory system. In this concept, information abstraction during sleep is considered a consequence of the gradual redistribution of representations from hippocampal to primarily neocortical networks serving as long-term stores. Mechanisms underlying active systems consolidation shall be investigated, together with behavioral indicators of memory, at the level of large-scale network activity and oscillations (by fMRI, EEG, local field potential recordings, wide-field fluorescence microscopy) as well as at the level of microcircuits and single cells (by single unit recordings and two-photon imaging). For our ultimate aim to establish active systems consolidation of abstracted gist memory as a fundamental function of sleep, we will characterize the consolidation process in the sleeping brain for widely different (social and non-social) stimulus domains, and identify ontogenetic and phylogenetic regularities in this process. Understanding the memory function of sleep shall pave the way for translational approaches to ameliorate diseases in clinical settings and to enhance cognitive capabilities in educational settings.

• DFG Programme: Research Units
• International Connection: United Kingdom

Projects

• Abstraction of social and emotional gist during sleep in children with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) (Applicants Conzelmann, Ph.D., Annette ;  Ngo, Hong-Viet ;  Prehn-Kristensen, Alexander )
• Contribution of the cortico-hippocampal neuro-glial network to memory processing during sleep (Applicants Garaschuk, Olga ;  Marshall, Lisa )
• Coordination Funds (Applicant Born, Jan )
• Long-term discrimination and generalization of fear and extinction memories during sleep (Applicants Ehrlich, Ingrid ;  Wilhelm-Groch, Ines )
• Reactivation and abstraction of self-related social information during sleep (Applicants Diekelmann, Ph.D., Susanne ;  Krach, Sören )
• Sleep-dependent memory consolidation in infants – The impact of language on the type of transformation (Applicant Friedrich, Manuela )
• Sleep-dependent transformation of episodic memory during early life (Applicants Born, Jan ;  Inostroza, Ph.D., Marion )
• Sleep shapes hippocampal representations towards enhanced pattern separation and completion (Applicants Bartsch, Thorsten ;  Burgalossi, Ph.D., Andrea )
• Transcranial brain stimulation to study memory processing and synaptic plasticity during sleep (Applicants Bergmann, Til Ole ;  Ziemann, Ulf )

• Spokesperson: Professor Dr. Jan Born