OBJECTIVE—Nocturnal hypoglycemia represents an important problem for diabetic patients, which has been primarily attributed to an attenuated hormonal counterregulation during sleep. So far, hypoglycemia counterregulation has been exclusively examined during early nocturnal sleep, although early sleep differs markedly in sleep stage architecture from late sleep. Here, we investigated whether awa...

'Complexity science' is a rapidly developing research direction with applications in a multitude of fields that study complex systems consisting of a number of nonlinear elements with interesting dynamics and mutual interactions. This Theme Issue 'The complexity of sleep' aims at fostering the application of complexity science to sleep research, because the brain in its different sleep stages a...

Event-related potential (ERP) is one of the best techniques for studying information processing during sleep because it does not require behavioral responses or consciousness awareness. Several ERP components have been identified during non-rapid eye movement (NREM) sleep, but the associated underlying processes of these waveforms remain unclear. The present study examines the effect of sleep s...

We recorded all-night electroencephalograms (EEGs)/polysomnograms on 2 consecutive nights from 4 children (ages 4-11 years) with Rett syndrome. The first 10 sec of each 60 sec epoch were analyzed with counts of left and right hemisphere spikes and correlated with sleep stage. Spike counts were lowest during wakefulness. Spikes were most frequent over parasagittal regions during all sleep stages...

Human deep sleep is characterized by reduced sensory activity, responsiveness to stimuli, and conscious awareness. Given its ubiquity and reversible nature, it represents an attractive paradigm to study the neural changes which accompany the loss of consciousness in humans. In particular, the deepest stages of sleep can serve as an empirical test for the predictions of theoretical models relati...

The purpose of this study was to examine the effects of a truss mattress upon sleep and bed climate. The truss mattress which has been designed to decrease the pressure and bed climate humidity was tested. Six healthy female volunteers with a mean age of 23.3 years, served as subjects. The experiment was carried out under two conditions: a truss mattress (T) and a futon (F) (Japanese bedding). ...

STUDY OBJECTIVES The program provides a unique opportunity to compare a large number of scorers with varied levels of experience to determine sleep stage scoring agreement. The objective is to examine areas of disagreement to inform future revisions of the AASM Manual for the Scoring of Sleep and Associated Events. METHODS The sample included 9 record fragments, 1,800 epochs and more than 3,2...

The goal of this study is to contribute to discussions about age-related changes in electroencephalogram (EEG) complexity. Eight characteristics of complexity were evaluated for sleep EEG of 175 healthy subjects. The complexity of the sleep EEG significantly increased up to the age of about 60 years. Over 60 years, the complexity stagnated or slightly decreased. The same tendencies were manifes...

A whole body indirect calorimeter provides accurate measurement of energy expenditure over long periods of time, but it has limitations to assess its dynamic changes. The present study aimed to improve algorithms to compute O(2) consumption and CO(2) production by adopting a stochastic deconvolution method, which controls the relative weight of fidelity to the data and smoothness of the estimat...

The sleeping neocortex shows nested oscillatory activity in different frequency ranges, characterized by fluctuations between "up-states" and "down-states." High-density neuronal ensemble recordings in rats now reveal the interaction between synchronized activity in the hippocampus and neocortex: Electroencephalographic sharp waves in the hippocampus were more probable during down-states than d...