{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T14:37:10Z","timestamp":1768919830538,"version":"3.49.0"},"reference-count":53,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2024,10,6]],"date-time":"2024-10-06T00:00:00Z","timestamp":1728172800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Instituto de Salud Carlos III (ISCIII)","award":["PI23\/00393"],"award-info":[{"award-number":["PI23\/00393"]}]},{"name":"FEDER (Fonds Europeen de Development Economique et Regional)","award":["PI23\/00393"],"award-info":[{"award-number":["PI23\/00393"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sciences"],"abstract":"<jats:p>We used numerical methods to define the normative structure of the different stages of sleep and wake (W) in a pilot study of 19 participants without pathology (18\u201364 years old) using a double-banana bipolar montage. Artefact-free 120\u2013240 s epoch lengths were visually identified and divided into 1 s windows with a 10% overlap. Differential channels were grouped into frontal, parieto-occipital, and temporal lobes. For every channel, the power spectrum (PS) was calculated via fast Fourier transform and used to compute the areas for the delta (0\u20134 Hz), theta (4\u20138 Hz), alpha (8\u201313 Hz), and beta (13\u201330 Hz) bands, which were log-transformed. Furthermore, Pearson\u2019s correlation coefficient and coherence by bands were computed. Differences in logPS and synchronization from the whole scalp were observed between the sexes for specific stages. However, these differences vanished when specific lobes were considered. Considering the location and stages, the logPS and synchronization vary highly and specifically in a complex manner. Furthermore, the average spectra for every channel and stage were very well defined, with phase-specific features (e.g., the sigma band during N2 and N3, or the occipital alpha component during wakefulness), although the slow alpha component (8.0\u20138.5 Hz) persisted during NREM and REM sleep. The average spectra were symmetric between hemispheres. The properties of K-complexes and the sigma band (mainly due to sleep spindles\u2014SSs) were deeply analyzed during the NREM N2 stage. The properties of the sigma band are directly related to the density of SSs. The average frequency of SSs in the frontal lobe was lower than that in the occipital lobe. In approximately 30% of the participants, SSs showed bimodal components in the anterior regions. qEEG can be easily and reliably used to study sleep in healthy participants and patients.<\/jats:p>","DOI":"10.3390\/brainsci14101007","type":"journal-article","created":{"date-parts":[[2024,10,7]],"date-time":"2024-10-07T06:23:18Z","timestamp":1728282198000},"page":"1007","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Structure of Spectral Composition and Synchronization in Human Sleep on the Whole Scalp: A Pilot Study"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6870-8409","authenticated-orcid":false,"given":"Jes\u00fas","family":"Pastor","sequence":"first","affiliation":[{"name":"Clinical Neurophysiology and Instituto de Investigaci\u00f3n Biom\u00e9dica, Hospital Universitario de La Princesa, C\/Diego de Le\u00f3n 62, 28006 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paula","family":"Garrido Zabala","sequence":"additional","affiliation":[{"name":"Facultad de Ciencias de la Salud, Universidad Camilo Jos\u00e9 Cela, C\/Castillo de Alarc\u00f3n 49, Villafranca del Castillo, 28692 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3240-2234","authenticated-orcid":false,"given":"Lorena","family":"Vega-Zelaya","sequence":"additional","affiliation":[{"name":"Clinical Neurophysiology and Instituto de Investigaci\u00f3n Biom\u00e9dica, Hospital Universitario de La Princesa, C\/Diego de Le\u00f3n 62, 28006 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,10,6]]},"reference":[{"key":"ref_1","unstructured":"Stickgold, R., and Walker, M.P. (2009). Sleep architecture. The Neuroscience of Sleep, Academic Press."},{"key":"ref_2","unstructured":"Kandel, E.R., Schwartz, J.H., and Jessel, T.M. (2000). Sleep and Dreaming. Principles of Neuroscience, McGraw-Hill. [4th ed.]."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3252","DOI":"10.1523\/JNEUROSCI.13-08-03252.1993","article-title":"Novel slow (<1 Hz) oscillation of neocortical neurons in vivo: Depolarizing and hyperpolarizing components","volume":"13","author":"Steriade","year":"1993","journal-title":"J. Neurosci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3284","DOI":"10.1523\/JNEUROSCI.13-08-03284.1993","article-title":"The slow (<1 Hz) oscillation in reticular thalamic and thalamocortical neurons: Scenario of sleep rhythm generation in interacting thalamic and neocortical networks","volume":"13","author":"Steriade","year":"1993","journal-title":"J. Neurosci."},{"key":"ref_5","unstructured":"Teofilo, L.-C. (2006). Normal Human Sleep. Sleep: A Comprehensive Handboock, John and Wiley and Son."},{"key":"ref_6","unstructured":"Shneerson, J.M. (2005). Sleep Medicine: A Guide to Sleep and Its Disorders, Blackwell Publishing Ltd.. [2nd ed.]."},{"key":"ref_7","unstructured":"Kryger, M.H., Roht, T.W., and Dement, C. (2011). Normal human sleep an overview. Principles and Practice of Sleep Medicine, Elsevier. [5th ed.]."},{"key":"ref_8","unstructured":"Purves, D., Augustine, G.J., Fitzpatrick, D., Hall, W.C., LaMantia, A.S., McNamara, J.O., and Williams, S.M. (2004). Sleep and Wakefulness In Neuroscience, Sinauer Associates. [3rd ed.]."},{"key":"ref_9","unstructured":"Kryger, M.H., Roth, T., and Dement, W.C. (2011). Principles and Practice of Sleep Medicine, Elsevier. [5th ed.]."},{"key":"ref_10","unstructured":"American Academy of Sleep Medicine (2024, July 20). AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications (Version 3). Available online: https:\/\/cir.nii.ac.jp\/crid\/1370004237604151044."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"113331","DOI":"10.1016\/j.eswa.2020.113331","article-title":"Multitaper-based method for automatic k-complex detection in human sleep EEG","volume":"151","author":"Oliveir","year":"2020","journal-title":"Expert Syst. Appl."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.bspc.2014.01.010","article-title":"Automatic detection of spindles and K-complexes in sleep EEG using switching multiple models","volume":"10","author":"Camilleri","year":"2014","journal-title":"Biomed. Signal Process. Control."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"294","DOI":"10.4236\/jbise.2009.25044","article-title":"Sleep spindles detection from human sleep EEG signals using autoregressive (AR) model: A surrogate data approach","volume":"2","author":"Perumalsamy","year":"2009","journal-title":"J. Biomed. Sci. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1111\/j.1469-8986.1991.tb03386.x","article-title":"Behavioral, event-related potential and EEG\/FFT changes at sleep onset","volume":"28","author":"Ogilvie","year":"1991","journal-title":"Psychophysiology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1016\/S0013-4694(97)00064-3","article-title":"FFT analysis of EEG during stage 2-to-REM transitions in narcoleptic patients and normal sleepers","volume":"103","author":"Hadjiyannakis","year":"1997","journal-title":"Electroen. Clin. Neuro."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"147","DOI":"10.2991\/jrnal.k.200909.001","article-title":"EEG based drowsiness detection using relative band power and short-time Fourier transform","volume":"7","author":"Krishnan","year":"2020","journal-title":"J. Robot. Netw. Artif. Life"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"477","DOI":"10.2147\/NSS.S295742","article-title":"Spectral power analysis of sleep electroencephalography in subjects with different severities of obstructive sleep apnea and healthy controls","volume":"13","author":"Kang","year":"2021","journal-title":"Nat. Sci. Sleep"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1007\/s10916-015-0219-1","article-title":"Mutual information analysis of sleep EEG in detecting psycho-physiological insomnia","volume":"39","author":"Aydin","year":"2015","journal-title":"J. Med. Syst."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1016\/j.cmpb.2013.07.006","article-title":"Automatic classification of sleep stages based on the time-frequency image of EEG signals","volume":"112","author":"Bajaj","year":"2013","journal-title":"Comput. Meth. Prog. Bio."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Huang, H., Zhang, J., Zhu, L., Tang, J., Lin, G., Kong, W., Lei, X., and Zhu, L. (2021). EEG-Based Sleep Staging Analysis with Functional Connectivity. Sensors, 21.","DOI":"10.3390\/s21061988"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1016\/0013-4694(69)90086-8","article-title":"Spectral analysis of the EEG of dominant and non-dominant alpha subjects during waking and sleeping","volume":"26","author":"Johnson","year":"1969","journal-title":"Electroencephalogr. Clin. Neurophysiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1159\/000115579","article-title":"Spectral analysis of all-night sleep EEG in healthy adults","volume":"22","author":"Dumermuth","year":"1983","journal-title":"Eur. Neurol."},{"key":"ref_23","first-page":"1","article-title":"Utility of video-electroencephalography monitoring for diagnosis of epilepsy and non-epileptic paroxysmal events","volume":"3","author":"Lopez","year":"2020","journal-title":"Arch. Women Health Care"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Pastor, J., and Vega-Zelaya, L. (2023). Normative Structure of Resting-State EEG in Bipolar Derivations for Daily Clinical Practice: A Pilot Study. Brain Sci., 13.","DOI":"10.3390\/brainsci13020167"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Vega-Zelaya, L., Mart\u00edn Abad, E., and Pastor, J. (2020). Quantified EEG for the characterization of epileptic seizures versus periodic activity in critically ill patients. Brain Sci., 10.","DOI":"10.3390\/brainsci10030158"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Pastor, J., Vega-Zelaya, L., and Martin Abad, E. (2020). Specific EEG encephalopathic pattern in SARS-CoV-2 patients. J. Clin. Med., 9.","DOI":"10.3390\/jcm9051545"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.ijpsycho.2005.04.001","article-title":"EEG coherence","volume":"57","author":"Ruchkin","year":"2005","journal-title":"Int. J. Psychophysiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.1016\/j.clinph.2008.01.013","article-title":"EEG power and coherence in autistic spectrum disorder","volume":"119","author":"Coben","year":"2008","journal-title":"Clin. Neurophysiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2585","DOI":"10.1111\/ejn.13854","article-title":"Single-trial log transformation is optimal in frequency analysis of resting EEG alpha","volume":"48","author":"Smulders","year":"2018","journal-title":"Eur. J. Neurosci."},{"key":"ref_30","unstructured":"Spiegel, M.R. (1991). Teor\u00eda de la correlaci\u00f3n. Spiegel MR: Estad\u00edstica. Madrid, McGraw-Hill; Interamericana."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1111\/1469-8986.3820232","article-title":"The effects of age and gender on sleep EEG power spectral density in the middle years of life (ages 20\u201360 years old)","volume":"38","author":"Carrier","year":"2001","journal-title":"Psychophysiology"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1016\/0197-4580(89)90004-3","article-title":"All night spectral analysis of EEG sleep in young adult and middle-aged male subjects","volume":"10","author":"Dijk","year":"1989","journal-title":"Neurobiol. Aging"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1088\/0967-3334\/22\/4\/305","article-title":"A method to standardize a reference of scalp EEG recordings to a point at infinity","volume":"22","author":"Yao","year":"2001","journal-title":"Physiol. Meas."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1111\/j.1528-1167.2007.01266.x","article-title":"Synchronization clusters of interictal activity in the lateral temporal cortex of epileptic patients: Intracranial analysis","volume":"49","author":"Ortega","year":"2008","journal-title":"Epilepsia"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Palmigiano, A., Pastor, J., Garc\u00eda de Sola, R., and Ortega, G.J. (2012). Stability of synchronization clusters and seizurability in temporal lobe epilepsy. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0041799"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1093\/sleep\/20.11.939","article-title":"Topographical distribution of spindles and K-complexes in normal subjects","volume":"20","author":"McCormic","year":"1997","journal-title":"Sleep"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1093\/sleep\/28.2.255","article-title":"The K-complex: A 7-decade history","volume":"28","author":"Colrain","year":"2005","journal-title":"Sleep"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/0013-4694(86)90173-2","article-title":"Late component variants of single auditory evoked responses during NREM sleep stage 2 in man","volume":"64","year":"1986","journal-title":"Electroencephalogr. Clin. Neurophysiol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/0013-4694(91)90021-U","article-title":"A model-based detector of vertex vawes and K complex in sleep electroencephalogram","volume":"78","author":"Kemp","year":"1991","journal-title":"Electroencephalogr. Clin. Neurophysiol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1548","DOI":"10.1016\/j.clinph.2014.10.158","article-title":"Inter-expert and intra-expert reliability in sleep spindle scoring","volume":"126","author":"Wendt","year":"2015","journal-title":"Clin. Neurophysiol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"805","DOI":"10.1152\/physrev.00042.2018","article-title":"Sleep spindles: Mechanisms and functions","volume":"100","author":"Fernandez","year":"2020","journal-title":"Physiol. Rev."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1038\/nmeth.2855","article-title":"Sleep-spindle detection: Crowdsourcing and evaluating performance of experts, non-experts and automated methods","volume":"11","author":"Warby","year":"2014","journal-title":"Nat. Methods"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1016\/j.neuroimage.2005.01.020","article-title":"An electroencephalographic fingerprint of human sleep","volume":"26","author":"Ferrara","year":"2005","journal-title":"Neuroimage"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1411","DOI":"10.5665\/SLEEP.1290","article-title":"Fast and slow spindles during the sleep slow oscillation: Disparate coalescence and engagement in memory processing","volume":"34","author":"Bergmann","year":"2011","journal-title":"Sleep"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"433","DOI":"10.3389\/fnhum.2017.00433","article-title":"Individual differences in frequency and topography of slow and fast sleep spindles","volume":"11","author":"Cox","year":"2017","journal-title":"Front Hum. Neurosci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1053\/smrv.2002.0252","article-title":"Sleep spindles: An overview","volume":"7","author":"Ferrara","year":"2003","journal-title":"Sleep Med. Rev."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1016\/S0168-0102(03)00007-5","article-title":"Sleep spindles in human prefrontal cortex: An electrocorticographic study","volume":"45","author":"Nakamura","year":"2003","journal-title":"Neurosci Res."},{"key":"ref_48","first-page":"400","article-title":"K-complexes and sleep spindles before transient activation during sleep","volume":"4","author":"Ehrhart","year":"1981","journal-title":"Sleep"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1093\/sleep\/5.1.58","article-title":"Dynamic relation of sleep spindles and K-complexes to spontaneous phasic arousal in sleeping human subjects","volume":"5","author":"Naitoh","year":"1982","journal-title":"Sleep"},{"key":"ref_50","first-page":"226","article-title":"The 0.02 Hz-oscillation in sigma power times spontaneous transitions from non-REM sleep","volume":"27","author":"Cardis","year":"2018","journal-title":"J. Sleep Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"847","DOI":"10.3389\/fphys.2017.00847","article-title":"Commentary: Coordinated infraslow neural and cardiac oscillations mark fragility and offline periods in mammalian sleep","volume":"8","author":"Manconi","year":"2017","journal-title":"Front Physiol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"8376108","DOI":"10.1155\/2016\/8376108","article-title":"Parietal fast sleep spindle density decrease in Alzheimer\u2019s disease and amnesic mild cognitive impairment","volume":"2016","author":"Gorgoni","year":"2016","journal-title":"Neural. Plast"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1159","DOI":"10.1097\/WNR.0b013e32830867c4","article-title":"Is there a link between sleep changes and memory in Alzheimer\u2019s disease?","volume":"19","author":"Rauchs","year":"2008","journal-title":"Neuroreport"}],"container-title":["Brain Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3425\/14\/10\/1007\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:11:24Z","timestamp":1760112684000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3425\/14\/10\/1007"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10,6]]},"references-count":53,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2024,10]]}},"alternative-id":["brainsci14101007"],"URL":"https:\/\/doi.org\/10.3390\/brainsci14101007","relation":{},"ISSN":["2076-3425"],"issn-type":[{"value":"2076-3425","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,10,6]]}}}