Ricerc@Sapienza

Objective/Background: Massive changes in brain morphology and function in the first years of life reveal a
postero-anterior trajectory of cortical maturation accompanied by regional modifications of NREM sleep.
One of the most sensible marker of this maturation process is represented by electroencephalographic
(EEG) activity within the frequency range of sleep spindles. However, direct evidence that these changes
actually reflect maturational modifications of fast and slow spindles still lacks.
Our study aimed at answering the following questions:

During the transition from wake to sleep, the human brain exhibits progressive, regional, and frequency-specific electroencephalographic (EEG) changes, mainly represented by (a) an increase of the slowest frequencies (≤ 7 Hz) with an anteroposterior gradient; (b) a shift from a posterior to an anterior dominance of alpha activity (8–12 Hz); (c) an increase in the sigma frequency range (~ 12–15 Hz), denoting the emergence of sleep spindles; and (d) a generalized reduction of the highest frequency activity (16–40 Hz).