Non-rapid eye movement sleep

About: Non-rapid eye movement sleep is a research topic. Over the lifetime, 8661 publications have been published within this topic receiving 389465 citations. The topic is also known as: NREM.

Psychological and physiological differences between good and poor sleepers.

Abstract: PHYSIOLOGICAL, PERSONALITY, AND EEG SLEEP PATTERNS OF 16 POOR-SLEEP GROUP (PSG) SS WERE COMPARED WITH 16 GOOD-SLEEP GROUP (GSG) SS. COMPARED WITH GOOD SLEEPERS, POOR SLEEPERS HAD LESS SLEEP TIME, A HIGHER PROPORTION OF STAGE 2 SLEEP, MARKEDLY LESS REM SLEEP DESPITE A SIMILAR NUMBER OF REM PERIODS, MORE AWAKENINGS, AND REQUIRED MORE TIME TO FALL ASLEEP. SIGNIFICANT PHYSIOLOGICAL DIFFERENCES BETWEEN THE GROUPS WERE OBSERVED DURING ALL STAGES OF SLEEP AND DURING A PRESLEEP PERIOD. PERSONALITY TEST RESULTS CLEARLY INDICATED A MUCH HIGHER PROBABILITY OF SYMPTOMATIC COMPLAINTS AMONG POOR SLEEPERS AS WELL AS A STRONG POTITIVE RELATIONSHIP BETWEEN DREAMING AND INDEXES OF PSYCHOPATHOLOGY. THIS STUDY DID NOT RESOLVE CAUSE AND EFFECT RELATIONSHIPS AMONG PHYSIOLOGICAL VARIABLES, PERSONALITY MEASURES, AMOUNT OF DREAMING, AND GOOD AND POOR SLEEP; HOWEVER, SIGNIFICANT EEG, PHYSIOLOGICAL, AND PSYCHOLOGICAL DIFFERENCES WERE DEMONSTRATED. (PsycINFO Database Record (c) 2006 APA, all rights reserved)

Comparison between subjective and actigraphic measurement of sleep and sleep rhythms

Abstract: Sleep is often assessed in circadian rhythm studies and long-term monitoring is required to detect any changes in sleep over time. The present study aims to investigate the ability of the two most commonly employed methods, actigraphy and sleep logs, to identify circadian sleep/wake disorders and measure changes in sleep patterns over time. In addition, the study assesses whether sleep measured by both methods shows the same relationship with an established circadian phase marker, urinary 6-sulphatoxymelatonin. A total of 49 registered blind subjects with different types of circadian rhythms were studied daily for at least four weeks. Grouped analysis of all study days for all subjects was performed for all sleep parameters (1062-1150 days data per sleep parameter). Good correlations were observed when comparing the measurement of sleep timing and duration (sleep onset, sleep offset, night sleep duration, day-time nap duration). However, the methods were poorly correlated in their assessment of transitions between sleep and wake states (sleep latency, number and duration of night awakenings, number of day-time naps). There were also large and inconsistent differences in the measurement of the absolute sleep parameters. Overall, actigraphs recorded a shorter sleep latency, advanced onset time, increased number and duration of night awakenings, delayed offset, increased night sleep duration and increased number and duration of naps compared with the subjective sleep logs. Despite this, there was good agreement between the methods for measuring changes in sleep patterns over time. In particular, the methods agreed when assessing changes in sleep in relation to a circadian phase marker (the 6-sulphatoxymelatonin (aMT6s) rhythm) in both entrained (n = 30) and free-running (n = 4) subjects.

Hierarchical nesting of slow oscillations, spindles and ripples in the human hippocampus during sleep

Abstract: During systems-level consolidation, mnemonic representations initially reliant on the hippocampus are thought to migrate to neocortical sites for more permanent storage, with an eminent role of sleep for facilitating this information transfer. Mechanistically, consolidation processes have been hypothesized to rely on systematic interactions between the three cardinal neuronal oscillations characterizing non-rapid eye movement (NREM) sleep. Under global control of de- and hyperpolarizing slow oscillations (SOs), sleep spindles may cluster hippocampal ripples for a precisely timed transfer of local information to the neocortex. We used direct intracranial electroencephalogram recordings from human epilepsy patients during natural sleep to test the assumption that SOs, spindles and ripples are functionally coupled in the hippocampus. Employing cross-frequency phase-amplitude coupling analyses, we found that spindles were modulated by the up-state of SOs. Notably, spindles were found to in turn cluster ripples in their troughs, providing fine-tuned temporal frames for the hypothesized transfer of hippocampal memory traces.