sleep stages


Summary: Periods of sleep manifested by changes in EEG activity and certain behavioral correlates; includes Stage 1: sleep onset, drowsy sleep; Stage 2: light sleep; Stages 3 and 4: delta sleep, light sleep, deep sleep, telencephalic sleep.

Top Publications

  1. Ayoub A, Aumann D, Hörschelmann A, Kouchekmanesch A, Paul P, Born J, et al. Differential effects on fast and slow spindle activity, and the sleep slow oscillation in humans with carbamazepine and flunarizine to antagonize voltage-dependent Na+ and Ca2+ channel activity. Sleep. 2013;36:905-11 pubmed publisher
  2. Wendt S, Christensen J, Kempfner J, Leonthin H, Jennum P, Sorensen H. Validation of a novel automatic sleep spindle detector with high performance during sleep in middle aged subjects. Conf Proc IEEE Eng Med Biol Soc. 2012;2012:4250-3 pubmed publisher
    ..3 %. The sleep spindle detector can be used to obtain measures of spindle count and density together with quantitative measures such as the mean spindle frequency, mean spindle amplitude, and mean spindle duration. ..
  3. Schönwald S, Carvalho D, de Santa Helena E, Lemke N, Gerhardt G. Topography-specific spindle frequency changes in obstructive sleep apnea. BMC Neurosci. 2012;13:89 pubmed publisher
  4. Elbaz I, Yelin Bekerman L, Nicenboim J, Vatine G, Appelbaum L. Genetic ablation of hypocretin neurons alters behavioral state transitions in zebrafish. J Neurosci. 2012;32:12961-72 pubmed publisher
    ..Our results further suggest a key role of HCRT neurons in mediating behavioral state transitions in response to external stimuli. ..
  5. Ftouni S, Sletten T, Howard M, Anderson C, Lenne M, Lockley S, et al. Objective and subjective measures of sleepiness, and their associations with on-road driving events in shift workers. J Sleep Res. 2013;22:58-69 pubmed publisher
    ..50 (95% CI, 1.81, 11.16)]. Under real-world driving conditions, shift-working nurses experience high levels of drowsiness as indicated by ocular measures, which are associated with impaired driving performance following night shift work. ..
  6. Simor P, Horváth K, Ujma P, Gombos F, Bodizs R. Fluctuations between sleep and wakefulness: wake-like features indicated by increased EEG alpha power during different sleep stages in nightmare disorder. Biol Psychol. 2013;94:592-600 pubmed publisher
    ..The topographical distribution and spectral components of REM alpha activity suggest that nightmare disordered subjects are characterized by wake-like electroencephalographic features during REM sleep. ..
  7. Crunelli V, Hughes S. The slow (<1 Hz) rhythm of non-REM sleep: a dialogue between three cardinal oscillators. Nat Neurosci. 2010;13:9-17 pubmed publisher
  8. Khushaba R, Kodagoda S, Lal S, Dissanayake G. Driver drowsiness classification using fuzzy wavelet-packet-based feature-extraction algorithm. IEEE Trans Biomed Eng. 2011;58:121-31 pubmed publisher
    ..The experimental results proved the significance of FMIWPT in extracting features that highly correlate with the different drowsiness levels achieving a classification accuracy of 95%-- 97% on an average across all subjects. ..
  9. Saper C, Fuller P, Pedersen N, Lu J, Scammell T. Sleep state switching. Neuron. 2010;68:1023-42 pubmed publisher
    ..We also review how homeostatic, circadian, and allostatic drives help regulate sleep state switching and discuss how breakdown of the switching mechanism may contribute to sleep disorders such as narcolepsy. ..

More Information


  1. Schumann A, Bartsch R, Penzel T, Ivanov P, Kantelhardt J. Aging effects on cardiac and respiratory dynamics in healthy subjects across sleep stages. Sleep. 2010;33:943-55 pubmed
    ..We also studied differences across sleep stages and night-time wake and investigated quasi-periodic variations associated with cardiac risk...
  2. Parrino L, Ferri R, Bruni O, Terzano M. Cyclic alternating pattern (CAP): the marker of sleep instability. Sleep Med Rev. 2012;16:27-45 pubmed publisher
  3. Tseng I, Liu H, Yuan R, Sheu J, Yu J, Hu C. Expression of inducible nitric oxide synthase (iNOS) and period 1 (PER1) clock gene products in different sleep stages of patients with cognitive impairment. J Clin Neurosci. 2010;17:1140-3 pubmed publisher
    ..Increased expression of iNOS during REM sleep of patients with AD might be a compensation mechanism for maintaining REM sleep. However, the precise role of nocturnal expression of iNOS in patients with AD requires further investigation. ..
  4. Lira F, Pimentel G, Santos R, Oyama L, Damaso A, Oller Do Nascimento C, et al. Exercise training improves sleep pattern and metabolic profile in elderly people in a time-dependent manner. Lipids Health Dis. 2011;10:1-6 pubmed publisher
    ..Suggesting that this population requires training strategy modifications as to ensure consistent alterations regarding metabolism. ..
  5. Liang S, Kuo C, Hu Y, Cheng Y. A rule-based automatic sleep staging method. J Neurosci Methods. 2012;205:169-76 pubmed publisher
    ..68% and 0.79, respectively. This method can integrate with portable PSG system for sleep evaluation at-home in the near future. ..
  6. Tononi G. Slow wave homeostasis and synaptic plasticity. J Clin Sleep Med. 2009;5:S16-9 pubmed
  7. Näsi T, Virtanen J, Noponen T, Toppila J, Salmi T, Ilmoniemi R. Spontaneous hemodynamic oscillations during human sleep and sleep stage transitions characterized with near-infrared spectroscopy. PLoS ONE. 2011;6:e25415 pubmed publisher
    ..The results suggest that scalp hemodynamic changes should be considered alongside cortical hemodynamic changes in NIRS sleep studies to assess the interaction between the autonomic and central nervous systems. ..
  8. Bizzotto R, Zamuner S, Mezzalana E, De Nicolao G, Gomeni R, Hooker A, et al. Multinomial logistic functions in markov chain models of sleep architecture: internal and external validation and covariate analysis. AAPS J. 2011;13:445-63 pubmed publisher
    ..chain models have been recently proposed to characterize the time course of transition probabilities between sleep stages in insomniac patients...
  9. Rutters F, Gonnissen H, Hursel R, Lemmens S, Martens E, Westerterp Plantenga M. Distinct associations between energy balance and the sleep characteristics slow wave sleep and rapid eye movement sleep. Int J Obes (Lond). 2012;36:1346-52 pubmed publisher
  10. Carrier J, Viens I, Poirier G, Robillard R, Lafortune M, Vandewalle G, et al. Sleep slow wave changes during the middle years of life. Eur J Neurosci. 2011;33:758-66 pubmed publisher
    ..Age-related SW changes may be associated with changes in synaptic density and white matter integrity and may underlie greater sleep fragmentation and difficulty in recuperating and maintaining sleep under challenges in older subjects. ..
  11. Kufoy E, Palma J, Lopez J, Alegre M, Urrestarazu E, Artieda J, et al. Changes in the heart rate variability in patients with obstructive sleep apnea and its response to acute CPAP treatment. PLoS ONE. 2012;7:e33769 pubmed publisher
    ..We also analyzed the heart rate changes and their relationship with CPAP treatment, sleep stages, sex and body mass index...
  12. Bersagliere A, Achermann P. Slow oscillations in human non-rapid eye movement sleep electroencephalogram: effects of increased sleep pressure. J Sleep Res. 2010;19:228-37 pubmed publisher
    ..This study does not question slow-wave activity as a marker of sleep homeostasis, as the observed changes occurred within the same frequency range. ..
  13. Ray L, Fogel S, Smith C, Peters K. Validating an automated sleep spindle detection algorithm using an individualized approach. J Sleep Res. 2010;19:374-8 pubmed publisher
    ..Given that interindividual differences are accounted for, we feel that automatic spindle detection provides an accurate and efficient alternative approach for detecting sleep spindles. ..
  14. Bizzotto R, Zamuner S, De Nicolao G, Karlsson M, Gomeni R. Multinomial logistic estimation of Markov-chain models for modeling sleep architecture in primary insomnia patients. J Pharmacokinet Pharmacodyn. 2010;37:137-55 pubmed publisher
    ..based on multinomial logistic functions which characterize the time course of transition probabilities between sleep stages in insomniac patients treated with placebo...
  15. Signal T, van den Berg M, Mulrine H, Gander P. Duration of sleep inertia after napping during simulated night work and in extended operations. Chronobiol Int. 2012;29:769-79 pubmed publisher
    ..When wakefulness is extended and napping occurs at midday (i.e., P2), nap opportunities of 40- and 60-min have the advantage over shorter duration sleep periods, as they result in performance benefits ?45 min after waking. ..
  16. Anderer P, Moreau A, Woertz M, Ross M, Gruber G, Parapatics S, et al. Computer-assisted sleep classification according to the standard of the American Academy of Sleep Medicine: validation study of the AASM version of the Somnolyzer 24 × 7. Neuropsychobiology. 2010;62:250-64 pubmed publisher
    ..Concerning the visual classification of sleep stages, these new rules are intended to replace the rules by Rechtschaffen and Kales (R&K)...
  17. Kalinchuk A, McCarley R, Porkka Heiskanen T, Basheer R. The time course of adenosine, nitric oxide (NO) and inducible NO synthase changes in the brain with sleep loss and their role in the non-rapid eye movement sleep homeostatic cascade. J Neurochem. 2011;116:260-72 pubmed publisher
    ..These data support the role of BF adenosine and NO in sleep homeostasis and indicate the temporal and spatial sequence of sleep homeostatic cascade for NO and adenosine...
  18. Duffy J, Lowe A, Silva E, Winkelman J. Periodic limb movements in sleep exhibit a circadian rhythm that is maximal in the late evening/early night. Sleep Med. 2011;12:83-8 pubmed publisher
    ..This evidence for a circadian rhythm in PLMS has implications for treatment and provides direction for future studies of the pathophysiology of this movement disorder. ..
  19. Darwent D, Ferguson S, Sargent C, Paech G, Williams L, Zhou X, et al. Contribution of core body temperature, prior wake time, and sleep stages to cognitive throughput performance during forced desynchrony. Chronobiol Int. 2010;27:898-910 pubmed publisher inappropriate phases of their circadian timekeeping system, with implications for the dynamics of ultradian sleep stages. The independent effects of these changes on cognitive throughput performance are not well understood...
  20. Gapelyuk A, Riedl M, Suhrbier A, Kraemer J, Bretthauer G, Malberg H, et al. Cardiovascular regulation in different sleep stages in the obstructive sleep apnea syndrome. Biomed Tech (Berl). 2011;56:207-13 pubmed publisher
    ..used to answer the question whether there are differences in cardiovascular regulation between the different sleep stages and groups. Moreover, the therapeutic effect of CPAP therapy in OSAS patients shall be investigated...
  21. Groeger J, Lo J, Burns C, Dijk D. Effects of sleep inertia after daytime naps vary with executive load and time of day. Behav Neurosci. 2011;125:252-60 pubmed publisher
    ..We conclude that executive functions take longer to return to asymptotic performance after sleep than does performance of simpler tasks which are less reliant on executive functions. ..
  22. Shekleton J, Parcell D, Redman J, Phipps Nelson J, Ponsford J, Rajaratnam S. Sleep disturbance and melatonin levels following traumatic brain injury. Neurology. 2010;74:1732-8 pubmed publisher
    ..We propose that elevated depression is associated with reduced sleep quality, and increased slow wave sleep is attributed to the effects of mechanical brain damage. ..
  23. Barakat M, Carrier J, Debas K, Lungu O, Fogel S, Vandewalle G, et al. Sleep spindles predict neural and behavioral changes in motor sequence consolidation. Hum Brain Mapp. 2013;34:2918-28 pubmed publisher
    ..Taken together, our results show that sleep spindles predict neural and behavioral changes in overnight motor sequence consolidation. ..
  24. Peter Derex L, Comte J, Mauguiere F, Salin P. Density and frequency caudo-rostral gradients of sleep spindles recorded in the human cortex. Sleep. 2012;35:69-79 pubmed publisher
    ..Mechanisms of caudo-rostral gradient modulation in spindle frequency and density may result from a complex interplay of intrinsic properties and extrinsic modulation of thalamocortical and corticothalamic neurons. ..
  25. Wamsley E, Tucker M, Payne J, Benavides J, Stickgold R. Dreaming of a learning task is associated with enhanced sleep-dependent memory consolidation. Curr Biol. 2010;20:850-5 pubmed publisher
    ..That similar effects were not observed during wakefulness suggests that these mnemonic processes are specific to the sleep state. ..
  26. BaHammam A, Alrajeh M, Albabtain M, Bahammam S, Sharif M. Circadian pattern of sleep, energy expenditure, and body temperature of young healthy men during the intermittent fasting of Ramadan. Appetite. 2010;54:426-9 pubmed publisher
    ..These results support our hypothesis that in addition to sudden shift in meal times, other factors may affect the sleep pattern and circadian rhythms during Ramadan. ..
  27. Dworak M, McCarley R, Kim T, Kalinchuk A, Basheer R. Sleep and brain energy levels: ATP changes during sleep. J Neurosci. 2010;30:9007-16 pubmed publisher
  28. Bianchi M, Cash S, MIETUS J, Peng C, Thomas R. Obstructive sleep apnea alters sleep stage transition dynamics. PLoS ONE. 2010;5:e11356 pubmed publisher
    ..However, because a single night of sleep contains insufficient transitions to characterize these dynamics, extended monitoring of sleep, probably at home, would be necessary for individualized clinical application. ..
  29. Ikeda H, Hayashi M. The effect of self-awakening from nocturnal sleep on sleep inertia. Biol Psychol. 2010;83:15-9 pubmed publisher
    ..The results of this study suggest that sleep inertia occurs after forced-awakening and that it can be prevented by self-awakening. ..
  30. Dehghani N, Cash S, Halgren E. Topographical frequency dynamics within EEG and MEG sleep spindles. Clin Neurophysiol. 2011;122:229-35 pubmed publisher
    ..The spatio-spectral-temporal evolution of spindles may reflect their possible involvement in coordinating cortical activity during consolidation. ..
  31. Blagrove M, Henley Einion J, Barnett A, Edwards D, Heidi Seage C. A replication of the 5-7 day dream-lag effect with comparison of dreams to future events as control for baseline matching. Conscious Cogn. 2011;20:384-91 pubmed publisher
    ..This may indicate a memory processing function for sleep, which the dream content may reflect. Participants' and three independent judges' mean ratings also confirmed a significant day-residue effect. ..
  32. Fraiwan L, Lweesy K, Khasawneh N, Fraiwan M, Wenz H, Dickhaus H. Classification of sleep stages using multi-wavelet time frequency entropy and LDA. Methods Inf Med. 2010;49:230-7 pubmed publisher
  33. Wamsley E, Tucker M, Shinn A, Ono K, Mckinley S, Ely A, et al. Reduced sleep spindles and spindle coherence in schizophrenia: mechanisms of impaired memory consolidation?. Biol Psychiatry. 2012;71:154-61 pubmed publisher
  34. LANDSNESS E, Crupi D, Hulse B, Peterson M, Huber R, Ansari H, et al. Sleep-dependent improvement in visuomotor learning: a causal role for slow waves. Sleep. 2009;32:1273-84 pubmed
    ..These results support a causal role for sleep slow waves in sleep-dependent improvement of visuomotor performance. ..
  35. Ruch S, Markes O, Duss S, Oppliger D, Reber T, Koenig T, et al. Sleep stage II contributes to the consolidation of declarative memories. Neuropsychologia. 2012;50:2389-96 pubmed publisher
    ..These findings suggest that spindles, delta waves, and slow oscillations might promote memory consolidation not only during SWS, as shown earlier, but also during S2. ..
  36. Tamminen J, Payne J, Stickgold R, Wamsley E, Gaskell M. Sleep spindle activity is associated with the integration of new memories and existing knowledge. J Neurosci. 2010;30:14356-60 pubmed publisher
    ..Spindle activity appears to be particularly important for overnight integration of new memories with existing neocortical knowledge. ..
  37. Robillard R, Massicotte Marquez J, Kawinska A, Paquet J, Frenette S, Carrier J. Topography of homeostatic sleep pressure dissipation across the night in young and middle-aged men and women. J Sleep Res. 2010;19:455-65 pubmed publisher
    ..Importantly, ageing reduced the scale of homeostatic dissipation in both sexes, but this effect was more widespread across the brain in women. ..
  38. Martinez D, Breitenbach T, Lenz M. Light sleep and sleep time misperception - relationship to alpha-delta sleep. Clin Neurophysiol. 2010;121:704-11 pubmed publisher
    ..Alpha-delta sleep may be a marker of the physiological disorder underlying light sleep and sleep state misperception. ..
  39. Bodizs R, Gombos F, Kovacs I. Sleep EEG fingerprints reveal accelerated thalamocortical oscillatory dynamics in Williams syndrome. Res Dev Disabil. 2012;33:153-64 pubmed publisher
    ..Altogether these data suggest a decrease in alpha/low sigma power, as well as a redistribution of NREM sleep 8-16 Hz EEG power toward the higher frequencies and/or a higher frequency of NREM sleep thalamocortical oscillations in WS. ..
  40. Kalauzi A, Vuckovic A, Bojic T. EEG alpha phase shifts during transition from wakefulness to drowsiness. Int J Psychophysiol. 2012;86:195-205 pubmed publisher
    ..Areas of increased phase locking might be correlated with topography of synchronous neuronal assemblies conceptualized within neural correlates of consciousness. ..
  41. Arico D, Drago V, Foster P, Heilman K, Williamson J, Ferri R. Effects of NREM sleep instability on cognitive processing. Sleep Med. 2010;11:791-8 pubmed publisher
    ..Further studies are needed to better understand how CAP influences cognitive performance, especially frontally-dependent functions and memory. ..
  42. Abe T, Nonomura T, Komada Y, Asaoka S, Sasai T, Ueno A, et al. Detecting deteriorated vigilance using percentage of eyelid closure time during behavioral maintenance of wakefulness tests. Int J Psychophysiol. 2011;82:269-74 pubmed publisher
    ..2±0.2/20 trial/min) when PERCLOS was less than 11.5% per minute. Results suggest that, among the ocular variables, PERCLOS can prevent error or accident caused by low vigilance most effectively. ..
  43. Bachmann V, Klaus F, Bodenmann S, Schäfer N, Brugger P, Huber S, et al. Functional ADA polymorphism increases sleep depth and reduces vigilant attention in humans. Cereb Cortex. 2012;22:962-70 pubmed publisher
    ..5-12 Hz), sleepiness, fatigue, and ?-amylase in saliva were enhanced. These convergent data demonstrate that genetic reduction of ADA activity elevates sleep pressure and plays a key role in sleep and waking quality in humans. ..
  44. Acharya U, Chua E, Chua K, Min L, Tamura T. Analysis and automatic identification of sleep stages using higher order spectra. Int J Neural Syst. 2010;20:509-21 pubmed
    Electroencephalogram (EEG) signals are widely used to study the activity of the brain, such as to determine sleep stages. These EEG signals are nonlinear and non-stationary in nature...
  45. Swarnkar V, Abeyratne U, Hukins C. Objective measure of sleepiness and sleep latency via bispectrum analysis of EEG. Med Biol Eng Comput. 2010;48:1203-13 pubmed publisher
    ..It can also be developed into a sleep management system, wherein the SI is incorporated into a sleepiness index alert unit to alarm the user when sleepiness level crosses the predetermined threshold. ..
  46. Wamsley E, Perry K, Djonlagic I, Reaven L, Stickgold R. Cognitive replay of visuomotor learning at sleep onset: temporal dynamics and relationship to task performance. Sleep. 2010;33:59-68 pubmed
    ..These observations are interpreted in light of memory consolidation theory, and demonstrate that introspective reports can provide a valuable window on cognitive processing in the sleeping brain. ..
  47. Kokkinos V, Kostopoulos G. Human non-rapid eye movement stage II sleep spindles are blocked upon spontaneous K-complex coincidence and resume as higher frequency spindles afterwards. J Sleep Res. 2011;20:57-72 pubmed publisher
    ..This enhancement of spindle frequency could not be correlated to any of the KC parameters studied. The results of this study reveal a consistent interaction between the KC and the sleep spindle during NREM stage II in human sleep. ..
  48. Shaw N, Butler J, McKinney S, Nelson S, Ellenbogen J, Hall J. Insights into puberty: the relationship between sleep stages and pulsatile LH secretion. J Clin Endocrinol Metab. 2012;97:E2055-62 pubmed publisher
    ..1 pulse/h, n = 30) compared with all other sleep stages or periods of wake after sleep onset (P < 0.001)...
  49. Austin D, Beattie Z, Riley T, Adami A, Hagen C, Hayes T. Unobtrusive classification of sleep and wakefulness using load cells under the bed. Conf Proc IEEE Eng Med Biol Soc. 2012;2012:5254-7 pubmed publisher
    ..As this performance is over 27 sleep patients with a wide variety of diagnosis levels of sleep disordered breathing, age, body mass index, and other demographics, our method is robust and works well in clinical practice. ..
  50. Lang C, Brand S, Feldmeth A, Holsboer Trachsler E, Pühse U, Gerber M. Increased self-reported and objectively assessed physical activity predict sleep quality among adolescents. Physiol Behav. 2013;120:46-53 pubmed publisher
    ..Results indicate that among a non-clinical sample of adolescents increased PA is favorably associated with restoring sleep. Therefore, PA seems beneficial not only for physical and mental health, but also for sleep restoration. ..
  51. Demir N, Cokar O, Bolukbasi F, Demirbilek V, Yapici Z, Yalcinkaya C, et al. A close look at EEG in subacute sclerosing panencephalitis. J Clin Neurophysiol. 2013;30:348-56 pubmed publisher
  52. Kudlow P, Cha D, Lam R, McIntyre R. Sleep architecture variation: a mediator of metabolic disturbance in individuals with major depressive disorder. Sleep Med. 2013;14:943-9 pubmed publisher
    ..Validation of this marker would have broad clinical implications, such as primary, secondary, and tertiary preventative health strategies. ..
  53. Tanno S, Terao A, Okamatsu Ogura Y, Kimura K. Hypothalamic prepro-orexin mRNA level is inversely correlated to the non-rapid eye movement sleep level in high-fat diet-induced obese mice. Obes Res Clin Pract. 2013;7:e251-7 pubmed publisher