80 research outputs found
What in sleep is for memory
Since the seminal research by Jenkins and Dallenbach in the 1920s, it has been well proven that sleep has a major effect on the memory of pre-sleep material. However, there is still sparse knowledge about exactly which features of sleep have the most impact.
Studies which examined separately the role of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep provided largely controversial results and aroused harsh scientific debate, and the investigation of the link of specific sleep patterns to different memory systems (e.g. declarative vs. procedural) did not fully reconcile these inconsistencies. New research perspectives have been proposed in recent years to overcome the limits of the previous ‘single state’ approach. Psychological, neurophysiological and neuroanatomical data have recently suggested that NREM and REM sleep both play a part in memory consolidation.
We here present the hypothesis that NREM and REM are complementary for memory processes during sleep, thanks to their close interaction within the NREM–REM cycle, and discuss experimental data which prove the critical role of the sleep cycle for the morning recall of verbal material
Sleep organization in the first year of life: developmental trends in the quiet sleep-paradoxical sleep cycle
Yawning frequency and distribution in preterm and near term infants assessed throughtout 24-hour recordings
Yawning has been observed in foetuses and preterm infants. The aim of this study
was to assess the frequency and the 24 h distribution of yawning in preterm
infants. Twelve low-risk infants between 31 and 40 weeks of post-conceptional age
(PCA) were continuously video-recorded for 24 h in their incubator. Spontaneous
yawning was defined as opening of the mouth to its full extension in a dramatic
stretch movement. The results showed that the rate of yawning across the 24-h
period was 1.10/h. The highest incidence of yawns was in the waking motility
pattern when compared to active sleep or quiet sleep motility patterns. Between
31 and 40 weeks, yawn incidence significantly decreased mainly during the day.
The marked decrease in yawn frequency with age may be related to the development
of circadian and homeostatic control of sleep and wake
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