Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cycles
Sleep cycles are defined as episodes of non-rapid eye movement (non-REM) sleep followed by an episode of REM sleep. Fractal or aperiodic neural activity is a well-established marker of arousal and sleep stages measured using electroencephalography. We introduce a new concept of ‘fractal cycles’ of s...
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eLife Sciences Publications Ltd
2025-01-01
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| Online Access: | https://elifesciences.org/articles/96784 |
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| author | Yevgenia Rosenblum Mahdad Jafarzadeh Esfahani Nico Adelhöfer Paul Zerr Melanie Furrer Reto Huber Famke F Roest Axel Steiger Marcel Zeising Csenge G Horváth Bence Schneider Róbert Bódizs Martin Dresler |
| author_facet | Yevgenia Rosenblum Mahdad Jafarzadeh Esfahani Nico Adelhöfer Paul Zerr Melanie Furrer Reto Huber Famke F Roest Axel Steiger Marcel Zeising Csenge G Horváth Bence Schneider Róbert Bódizs Martin Dresler |
| author_sort | Yevgenia Rosenblum |
| collection | DOAJ |
| description | Sleep cycles are defined as episodes of non-rapid eye movement (non-REM) sleep followed by an episode of REM sleep. Fractal or aperiodic neural activity is a well-established marker of arousal and sleep stages measured using electroencephalography. We introduce a new concept of ‘fractal cycles’ of sleep, defined as a time interval during which time series of fractal activity descend to their local minimum and ascend to the next local maximum. We assess correlations between fractal and classical (i.e. non-REM – REM) sleep cycle durations and study cycles with skipped REM sleep. The sample comprised 205 healthy adults, 21 children and adolescents and 111 patients with depression. We found that fractal and classical cycle durations (89±34 vs 90±25 min) correlated positively (r=0.5, p<0.001). Children and adolescents had shorter fractal cycles than young adults (76±34 vs 94±32 min). The fractal cycle algorithm detected cycles with skipped REM sleep in 91–98% of cases. Medicated patients with depression showed longer fractal cycles compared to their unmedicated state (107±51 vs 92±38 min) and age-matched controls (104±49 vs 88±31 min). In conclusion, fractal cycles are an objective, quantifiable, continuous and biologically plausible way to display sleep neural activity and its cycles. |
| format | Article |
| id | doaj-art-c0bc2561ab4e4b1fba20d6c58862c4e7 |
| institution | DOAJ |
| issn | 2050-084X |
| language | English |
| publishDate | 2025-01-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj-art-c0bc2561ab4e4b1fba20d6c58862c4e72025-08-20T02:47:35ZengeLife Sciences Publications LtdeLife2050-084X2025-01-011310.7554/eLife.96784Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cyclesYevgenia Rosenblum0https://orcid.org/0000-0001-6792-787XMahdad Jafarzadeh Esfahani1Nico Adelhöfer2Paul Zerr3Melanie Furrer4Reto Huber5Famke F Roest6Axel Steiger7Marcel Zeising8Csenge G Horváth9Bence Schneider10Róbert Bódizs11Martin Dresler12https://orcid.org/0000-0001-7441-3818Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behavior, Nijmegen, NetherlandsRadboud University Medical Centre, Donders Institute for Brain, Cognition and Behavior, Nijmegen, NetherlandsRadboud University Medical Centre, Donders Institute for Brain, Cognition and Behavior, Nijmegen, NetherlandsRadboud University Medical Centre, Donders Institute for Brain, Cognition and Behavior, Nijmegen, NetherlandsChild Development Center and Children’s Research Center, University Children's Hospital Zürich, University of Zürich, Zürich, SwitzerlandChild Development Center and Children’s Research Center, University Children's Hospital Zürich, University of Zürich, Zürich, Switzerland; Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich, Zurich, SwitzerlandRadboud University Medical Centre, Donders Institute for Brain, Cognition and Behavior, Nijmegen, NetherlandsMax Planck Institute of Psychiatry, Munich, GermanyKlinikum Ingolstadt, Centre of Mental Health, Ingolstadt, GermanySemmelweis University, Institute of Behavioural Sciences, Budapest, HungarySemmelweis University, Institute of Behavioural Sciences, Budapest, HungarySemmelweis University, Institute of Behavioural Sciences, Budapest, HungaryRadboud University Medical Centre, Donders Institute for Brain, Cognition and Behavior, Nijmegen, NetherlandsSleep cycles are defined as episodes of non-rapid eye movement (non-REM) sleep followed by an episode of REM sleep. Fractal or aperiodic neural activity is a well-established marker of arousal and sleep stages measured using electroencephalography. We introduce a new concept of ‘fractal cycles’ of sleep, defined as a time interval during which time series of fractal activity descend to their local minimum and ascend to the next local maximum. We assess correlations between fractal and classical (i.e. non-REM – REM) sleep cycle durations and study cycles with skipped REM sleep. The sample comprised 205 healthy adults, 21 children and adolescents and 111 patients with depression. We found that fractal and classical cycle durations (89±34 vs 90±25 min) correlated positively (r=0.5, p<0.001). Children and adolescents had shorter fractal cycles than young adults (76±34 vs 94±32 min). The fractal cycle algorithm detected cycles with skipped REM sleep in 91–98% of cases. Medicated patients with depression showed longer fractal cycles compared to their unmedicated state (107±51 vs 92±38 min) and age-matched controls (104±49 vs 88±31 min). In conclusion, fractal cycles are an objective, quantifiable, continuous and biologically plausible way to display sleep neural activity and its cycles.https://elifesciences.org/articles/96784sleep cyclesaperiodic activitynon-REM-REM sleep cyclesleep1/fantidepressants and sleep |
| spellingShingle | Yevgenia Rosenblum Mahdad Jafarzadeh Esfahani Nico Adelhöfer Paul Zerr Melanie Furrer Reto Huber Famke F Roest Axel Steiger Marcel Zeising Csenge G Horváth Bence Schneider Róbert Bódizs Martin Dresler Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cycles eLife sleep cycles aperiodic activity non-REM-REM sleep cycle sleep 1/f antidepressants and sleep |
| title | Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cycles |
| title_full | Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cycles |
| title_fullStr | Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cycles |
| title_full_unstemmed | Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cycles |
| title_short | Fractal cycles of sleep, a new aperiodic activity-based definition of sleep cycles |
| title_sort | fractal cycles of sleep a new aperiodic activity based definition of sleep cycles |
| topic | sleep cycles aperiodic activity non-REM-REM sleep cycle sleep 1/f antidepressants and sleep |
| url | https://elifesciences.org/articles/96784 |
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