2021 Volume 39 Issue 1 Pages 4-18
We used Hori’s EEG stages to quantitatively describe EEG changes during the sleep onset period (SOP).We have also described the significance of psychophysiological approaches to the wake-sleep transition period, the topographical characteristics of EEG activities in the SOP, and temporal dynamics of the relationship between the waking period before sleep onset and the progress of sleep onset. We expect helpful information providing insights into the consciousness, emotions, behaviors, and brain functions in the waking and sleeping states from investigating the SOP using EEG stages of sleep onset as the primary index and correlating it with behavioral and subjective indexes.