On the Role of Sleep Spindles and Slow Oscillations for Sleep-associated Memory Consolidation in 5- to 6-year-old Children

• In Event: Poster Session 10
  In Poster Session: PS 10 Topic - Biological Processes: Neuroscience and Genetics

Abstract

In young adults, the precise temporal coordination of fast spindles (~12.5 - 16 Hz) and slow oscillations (< 1 Hz) is considered a key mediator of memory consolidation during sleep (Diekelmann & Born, 2010). However, across development, spindle and slow oscillation morphology changes profoundly (Kurth et al., 2010; Purcell et al., 2017). Thus, it remains elusive whether the same mechanisms of sleep-associated memory consolidation as identified in adults are comparably functional in children. Here, we characterise slow (~9 - 12.5 Hz) and fast spindles and their temporal coupling to slow oscillations in 24 pre-schoolers. Further, we investigate whether slow and fast spindles and their modulation during slow oscillations are similarly associated with behavioural indicators of declarative memory consolidation as suggested from adult literature. Leveraging an individualised rhythm detection approach, we reliably identify an endogenous, development-specific fast spindle type, though nested in the adult-like slow spindle frequency range, along with a dominant slow spindle type. Further, time-frequency and PETH analyses indicate the presence of fast spindle-slow oscillation coupling already in pre-school children - though weaker and less precise than expected from adult research. While we do not find evidence for a critical contribution of the pattern of fast spindle modulation during slow oscillations for memory consolidation, crucially, robust regressions show that both, slow and fast spindles separately are differentially related to memory consolidation of items of varying encoding quality. To conclude, our results reveal two functionally relevant, endogenous spindle types in pre-school children despite not fully matured spindle–slow oscillation coupling.

Authors

• Ann-Kathrin Joechner, Max Planck Institute for Human Development
  Presenting Author

• Markus Werkle-Bergner, Max Planck Institute for Human Development
  Non-Presenting Author