Somnoscreen plus neuro

Sleep was continuously recorded during the night of the Sleep condition using standard polysomnography including recordings of electroencephalography (EEG; from F3, F4, C3, Cz, C4, P3, P4, referenced to linked electrodes attached to the mastoids, and an electrode at FPz serving as ground), the electrooculogram (EOG, from electrodes placed below the left and above the right canthi) and the electromyogram (EMG, from electrodes over the left and right musculus mentalis). Recordings were conducted using a portable amplifier and recording system (SOMNOscreen™ plus Neuro+, SOMNOmedics GmbH) to ensure undisturbed sleeping in the subject's home. All signals were sampled at a rate of 256 Hz and filtered between 0.3 and 35 Hz (for the EEG and EOG), and between 10 and 100 Hz (for the EMG), respectively. A 50‐Hz notch filter was applied to all channels.
Sleep stages were determined offline for subsequent 30‐second epochs, using standard criteria (Rechtschaffen & Kales, 1968). For each child, the TST, time spent in different sleep stages in minutes and percentage of TST, wake after sleep onset (WASO), as well as SWS and REM sleep latencies with reference to sleep onset were determined. Further spindle and power analyses were conducted with algorithms as described in Mölle, Marshall, Gais, and Born (2002) (see Appendix S2 for a detailed description of the sleep analyses).

In the Sleep condition, sleep was continuously recorded using a portable recording system (SOMNOscreen plus Neuro+, SOMNOmedics GmbH). Polysomnography recordings (sampling rate 256 Hz) included electroencephalography from F3, F4, C3, Cz, C4, P3, and P4 (referenced to linked mastoids, FPz as ground), two electromyogram electrodes and two electrooculogram electrodes. Preprocessing included a 50 Hz Notch filter, a 0.3–35 Hz bandpass filter for the EEG and EOG, and a 10–100 Hz filter for the EMG. Offline sleep scoring was done for 30-s epochs according to standard criteria [45 ] to determine total sleep time (TST), wake after sleep onset (WASO), time spent in non-rapid eye movement (non-REM) stages 1 and 2 and slow-wave sleep (SWS, stage 3 plus stage 4), as well as time spent in REM sleep. Scoring was done by experienced staff (EMK, KaZ, study nurse), with an inter-rater agreement >85%. In the case of ambiguous epochs, the scorers discussed the critical epochs and decided together for a sleep stage.