Research in recent years has supported the hypothesis that many properties of the electroencephalogram (EEG) are specific to an individual. In this study, the intra- and inter-individual variations of sleep EEG signals were investigated. This was carried out by analyzing the stability of the average EEG spectra individually computed for the Rechtschaffen and Kales (RK) sleep stages. Six EEG cha...

A Markov chain model has been proposed as a mechanism that generates human sleep stages. A method for estimating the parameters of the model, i.e., the transition probabilities (rates) between sleep stages, has been introduced and applied to 95 hypnograms taken from 23 subjects. The rates characterize interindividual differences and nightly variations of the sleep mechanism, related to sleep-on...

Growth and pubertal development are important health markers. We used the data of a longitudinal growth study on a contemporary sample of US youth to examine the relationship between peak height velocity (PHV) and Tanner staging. We observed a substantial variability in the timing of PHV across Tanner stages, which is an important consideration for clinicians when assessing growth.

BACKGROUND This study was undertaken to compare the sleep profiles of healthy infants in swaddling and sleeping bag conditions. METHODS Polysomnographs of 85 healthy infants (40 in the study group, 45 in the control group) with a mean age of 7.5 weeks were recorded in the sleeping laboratory. A positive decision from the local Ethics Committee and the written consent of the parents were obtai...

BACKGROUND Changes caused by clonidine in rodent electroencephalograms (EEG) have been reported with some inconsistency. For this reason, a pre-clinical study was conducted in order to confirm previous findings with both a standard spectral analysis and a sleep stage scoring procedure. In addition, a nonlinear technique for analysing the time-varying signals was implemented to compare its perfo...

While the functions of sleep remain largely unknown, one of the most exciting and contentious hypotheses is that sleep contributes importantly to memory. A large number of studies offer a substantive body of evidence supporting this role of sleep in what is becoming known as sleep-dependent memory processing. This review will provide evidence of sleep-dependent memory consolidation and sleep-de...

Digital acquisition and analysis of sleep data has become more common over the past 20 years. Many investigators have developed strategies to record and analyze sleep in a quantitative way. Initially, digital recording and analysis were restricted by technical limitations. With current technology, the technical limitations of computer acquisition, data storage, and analysis are less constrainin...