Sleep and memory formation in infants and toddlers

• Applicant: Dr. Manuela Friedrich
• Subject Area: Developmental and Educational Psychology
• Term: from 2012 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 222228420

Within the first funding period of the project we were able to show that sleep substantially affects lexical-semantic memory in infants and toddlers. In addition, we demonstrated that, while sleeping, the infant brain aggregates similar experiences and creates new generalized knowledge. This first observed generalization of word meanings during infant sleep is associated with processes of neural plasticity, which appear as sleep spindle activity in an EEG (Friedrich et al., 2015, Nature Communications). In the requested new funding period we aim to further investigate the impact of sleep on infant memory and language development. We propose to determine the differential role of memory-related sleep components (REM sleep, NonREM sleep, sleep spindles, slow wave activity) for the different fields of early language acquisition (phonology, prosody, syntax, semantics), and its developmental trajectory. We particularly focus on the distinction of explicit (declarative) and implicit (procedural) memory, since in adults, the consolidation of these memory types is supported by different components of sleep architecture. Whilst the acquisition of lexical-semantic knowledge (word meanings) represents a kind of declarative memory formation that benefits from a component of infant NonREM sleep, as we have shown in the first funding period, the learning of phonological and prosodic regularities (word form and word stress) as well as the acquisition of syntactic relations (grammatical rules) is procedural in first language acquisition and could, therefore, be supported by REM sleep. Of particular interest in this context is to what extend the high proportion of REM sleep during early developmental periods and the increasing portion of NonREM sleep in the course of development are involved in qualitative and quantitative changes of sleep-dependent memory consolidation.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Cooperation Partners: Professor Dr. Jan Born; Professorin Dr. Angela Friederici; Dr. Ines Wilhelm-Groch