Co-evolution of Sleep Oscillations and Cognition from Childhood up to Young Adulthood

Introduction:
The period from childhood to young adulthood is marked by significant changes in sleep. Especially sleep spindles and slow oscillations are known to undergo drastic maturational changes during this time of life. We here present a longitudinal approach investigating the role of sleep for developmental changes in cognitive performance over the lifespan.
Method:
We assessed memory performance (word-pair association task) and intelligence (Wechsler IQ) in one sample of subjects (N=28, 19 female) during (1) childhood (~9.5yrs), (2) adolescence (~16yrs) and (3) young adulthood (~22.5yrs). Ambulatory sleep polysomnography was recorded during 6 nights, with two nights (baseline, experimental night) at each of the three measurements.
Results:
Preliminary results show that memory performance in the word-pair association task increased over time from childhood up to young adulthood. Regarding sleep physiology, we found that higher slow (11–13 Hz) than fast (13–15 Hz) spindle density at frontal, central, and parietal sites during childhood was followed by a shift to higher fast than slow spindle density at central and parietal sites during both adolescence and young adulthood.
Conclusion:
This suggests that maturation of spindle topography develops throughout adolescence and further proceeds until young adulthood. Importantly, we found that changes in sleep spindles and their precise interplay with slow oscillations may serve as a model for sleep-dependent declarative memory network development. In sum we provide evidence that the development of sleep oscillations and memory networks are intimately linked, hallmarking an important milestone in human cognitive development.