Background Since their introduction at the beginning of the 1990s the short half-life nonbenzodiazepine hypnotics, zolpidem and zopiclone, rapidly were among the most frequently prescribed hypnotics. Surveys showed that around 1996 the most frequently prescribed hypnotic in the US was zolpidem, while zolpidem and zopiclone were among the five most frequently used hypnotics in Europe [1, 2]. The...

Sleep has been identified as a critical brain state enhancing the probability of gaining insight into covert task regularities. Both non-rapid eye movement (NREM) and rapid eye movement (REM) sleep have been implicated with offline re-activation and reorganization of memories supporting explicit knowledge generation. According to two-stage models of sleep function, offline processing of information...

We previously reported that patients with schizophrenia failed to demonstrate normal sleep-dependent improvement in motor procedural learning. Here, we tested whether this failure was associated with the duration of Stage 2 sleep in the last quartile of the night (S2q4) and with spindle activity during this epoch. Fourteen patients with schizophrenia and 15 demographically matched controls perf...

A novel technique, the Delay Vector Variance method, which provides modelindependent characterisation of time series in terms of their predictability is introduced and applied in a biomedical context. The merits of the procedure are demonstrated in a mode segmentation context on a set of long nonstationary physiological signals, obtained from subjects undergoing different sleep and wake stages....

There is a growing body of evidence in support of sleep-dependent memory consolidation and plasticity. However, there are also examples of memory development and plasticity in the absence of sleep, casting doubt on an exclusive sleep-dependent memory hypothesis. As CMLS, Cell. Mol. Life Sci. 61 (2004) 3009–3015 1420-682X/04/243009-07 DOI 10.1007/s00018-004-4351-1 © Birkhäuser Verlag, Basel, 200...

Dreaming is an expression of vivid imagery with a seemingly storylike structure (1-3). Early observations (4,5) temporally linked vivid dreaming with REM sleep, an association which many took to be an exclusive one (e.g., 6-8). However, when the definition of dreaming was expanded to include more general forms of cognition (9), more serious consideration was given to the notion that dreaming is...

BACKGROUND Solving a task with insight has been associated with occipital and right-hemisphere activations. The present study tested the hypothesis if sleep-related alterations in functional activation states modulate the probability of insight into a hidden abstract regularity of a task. METHODOLOGY State-dependent functional activation was measured by beta and alpha electroencephalographic ...

A novel framework for joint detection of sleep spindles and K-complex events, two hallmarks of sleep stage S2, is proposed. Sleep electroencephalography (EEG) signals are split into oscillatory (spindles) and transient (K-complex) components. This decomposition is conveniently achieved by applying morphological component analysis (MCA) to a sparse representation of EEG segments obtained by the ...