Ricerc@Sapienza

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).

The sleep onset (SO) process is characterized by gradual electroencephalographic (EEG) changes. The interest for the possibility to manipulate the electrophysiological pattern of the wake-sleep transition is recently growing. This review aims to describe the EEG modifications of the SO process in healthy humans and the evidence about their experimental manipulation. We provide an overview of the electrophysiological changes during the wake-sleep transition, considering several methods to study the EEG signals.

Sleep has a crucial role in memory processes, and maturational changes in sleep electrophysiology
are involved in cognitive development. Albeit both sleep and memory alterations have
been observed in Developmental Dyslexia (DD), their relation in this population has been scarcely
investigated, particularly concerning topographical aspects. The study aimed to compare sleep
topography and associated sleep-related declarative memory consolidation in participants with DD