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Wei X, Avigdor T, Ho A, Minato E, Garcia-Asensi A, Royer J, Wang YL, Travnicek V, Schiller K, Bernhardt BC, Frauscher B. ANPHY-Sleep: an Open Sleep Database from Healthy Adults Using High-Density Scalp Electroencephalogram. Sci Data 2024; 11:896. [PMID: 39154027 PMCID: PMC11330504 DOI: 10.1038/s41597-024-03722-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 07/29/2024] [Indexed: 08/19/2024] Open
Abstract
Well-documented sleep datasets from healthy adults are important for sleep pattern analysis and comparison with a wide range of neuropsychiatric disorders. Currently, available sleep datasets from healthy adults are acquired using low-density arrays with a minimum of four electrodes in a typical sleep montage. The low spatial resolution is thus prohibitive for the analysis of the spatial structure of sleep. Here we introduce an open-access sleep dataset from 29 healthy adults (13 female, aged 32.17 ± 6.30 years) acquired at the Montreal Neurological Institute. The dataset includes overnight polysomnograms with high-density scalp electroencephalograms incorporating 83 electrodes, electrocardiogram, electromyogram, electrooculogram, and an average of electrode positions using manual co-registrations and sleep scoring annotations. Data characteristics and group-level analysis of sleep properties were assessed. The database can be accessed through ( https://doi.org/10.17605/OSF.IO/R26FH ). This is the first high-density electroencephalogram open sleep database from healthy adults, allowing researchers to investigate sleep physiology at high spatial resolution. We expect that this database will serve as a valuable resource for studying sleep physiology and for benchmarking sleep pathology.
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Affiliation(s)
- Xiaoyan Wei
- Analytical Neurophysiological Lab, Department of Neurology, Duke University, Durham, North Carolina, USA
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Tamir Avigdor
- Analytical Neurophysiological Lab, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
- Multimodal Functional Imaging Lab, Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Alyssa Ho
- Analytical Neurophysiological Lab, Department of Neurology, Duke University, Durham, North Carolina, USA
| | - Erica Minato
- Analytical Neurophysiological Lab, Department of Neurology, Duke University, Durham, North Carolina, USA
| | - Alfonso Garcia-Asensi
- Adult Sleep Laboratory - Montreal Chest Institute, McGill University Health Centre (MUHC), Montreal, Quebec, Canada
| | - Jessica Royer
- Multimodal Imaging and Connectome Analysis (MICA) Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Yingqi Laetitia Wang
- Analytical Neurophysiological Lab, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Vojtech Travnicek
- The Czech Academy of Sciences, Institute of Scientific Instruments, Brno, Czech Republic
- International Clinical Research Centre, St Anne's University Hospital Brno, Brno, Czech Republic
| | - Katharina Schiller
- Analytical Neurophysiological Lab, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Boris C Bernhardt
- Multimodal Imaging and Connectome Analysis (MICA) Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Birgit Frauscher
- Analytical Neurophysiological Lab, Department of Neurology, Duke University, Durham, North Carolina, USA.
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA.
- Analytical Neurophysiological Lab, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.
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Schmidig FJ, Ruch S, Henke K. Episodic long-term memory formation during slow-wave sleep. eLife 2024; 12:RP89601. [PMID: 38661727 PMCID: PMC11045222 DOI: 10.7554/elife.89601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
We are unresponsive during slow-wave sleep but continue monitoring external events for survival. Our brain wakens us when danger is imminent. If events are non-threatening, our brain might store them for later consideration to improve decision-making. To test this hypothesis, we examined whether novel vocabulary consisting of simultaneously played pseudowords and translation words are encoded/stored during sleep, and which neural-electrical events facilitate encoding/storage. An algorithm for brain-state-dependent stimulation selectively targeted word pairs to slow-wave peaks or troughs. Retrieval tests were given 12 and 36 hr later. These tests required decisions regarding the semantic category of previously sleep-played pseudowords. The sleep-played vocabulary influenced awake decision-making 36 hr later, if targeted to troughs. The words' linguistic processing raised neural complexity. The words' semantic-associative encoding was supported by increased theta power during the ensuing peak. Fast-spindle power ramped up during a second peak likely aiding consolidation. Hence, new vocabulary played during slow-wave sleep was stored and influenced decision-making days later.
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Affiliation(s)
| | - Simon Ruch
- Institute of Psychology, University of BernBernSwitzerland
- Faculty of Psychology, UniDistance SuisseBrigSwitzerland
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3
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Jourde HR, Merlo R, Brooks M, Rowe M, Coffey EBJ. The neurophysiology of closed-loop auditory stimulation in sleep: A magnetoencephalography study. Eur J Neurosci 2024; 59:613-640. [PMID: 37675803 DOI: 10.1111/ejn.16132] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 08/01/2023] [Accepted: 08/08/2023] [Indexed: 09/08/2023]
Abstract
Closed-loop auditory stimulation (CLAS) is a brain modulation technique in which sounds are timed to enhance or disrupt endogenous neurophysiological events. CLAS of slow oscillation up-states in sleep is becoming a popular tool to study and enhance sleep's functions, as it increases slow oscillations, evokes sleep spindles and enhances memory consolidation of certain tasks. However, few studies have examined the specific neurophysiological mechanisms involved in CLAS, in part because of practical limitations to available tools. To evaluate evidence for possible models of how sound stimulation during brain up-states alters brain activity, we simultaneously recorded electro- and magnetoencephalography in human participants who received auditory stimulation across sleep stages. We conducted a series of analyses that test different models of pathways through which CLAS of slow oscillations may affect widespread neural activity that have been suggested in literature, using spatial information, timing and phase relationships in the source-localized magnetoencephalography data. The results suggest that auditory information reaches ventral frontal lobe areas via non-lemniscal pathways. From there, a slow oscillation is created and propagated. We demonstrate that while the state of excitability of tissue in auditory cortex and frontal ventral regions shows some synchrony with the electroencephalography (EEG)-recorded up-states that are commonly used for CLAS, it is the state of ventral frontal regions that is most critical for slow oscillation generation. Our findings advance models of how CLAS leads to enhancement of slow oscillations, sleep spindles and associated cognitive benefits and offer insight into how the effectiveness of brain stimulation techniques can be improved.
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Affiliation(s)
- Hugo R Jourde
- Concordia University, Montreal, Quebec, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Quebec, Canada
- Centre for Research on Brain, Language and Music (CRBLM), Montreal, Quebec, Canada
- Quebec Bio-Imaging Network (QBIN), Sherbrooke, Quebec, Canada
| | | | - Mary Brooks
- Concordia University, Montreal, Quebec, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Quebec, Canada
- Centre for Research on Brain, Language and Music (CRBLM), Montreal, Quebec, Canada
- Quebec Bio-Imaging Network (QBIN), Sherbrooke, Quebec, Canada
| | | | - Emily B J Coffey
- Concordia University, Montreal, Quebec, Canada
- International Laboratory for Brain, Music and Sound Research (BRAMS), Montreal, Quebec, Canada
- Centre for Research on Brain, Language and Music (CRBLM), Montreal, Quebec, Canada
- Quebec Bio-Imaging Network (QBIN), Sherbrooke, Quebec, Canada
- McGill University, Montreal, Quebec, Canada
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4
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Wunderlin M, Zeller CJ, Senti SR, Fehér KD, Suppiger D, Wyss P, Koenig T, Teunissen CE, Nissen C, Klöppel S, Züst MA. Acoustic stimulation during sleep predicts long-lasting increases in memory performance and beneficial amyloid response in older adults. Age Ageing 2023; 52:afad228. [PMID: 38163288 PMCID: PMC10758173 DOI: 10.1093/ageing/afad228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND Sleep and neurodegeneration are assumed to be locked in a bi-directional vicious cycle. Improving sleep could break this cycle and help to prevent neurodegeneration. We tested multi-night phase-locked acoustic stimulation (PLAS) during slow wave sleep (SWS) as a non-invasive method to improve SWS, memory performance and plasma amyloid levels. METHODS 32 healthy older adults (agemean: 68.9) completed a between-subject sham-controlled three-night intervention, preceded by a sham-PLAS baseline night. RESULTS PLAS induced increases in sleep-associated spectral-power bands as well as a 24% increase in slow wave-coupled spindles, known to support memory consolidation. There was no significant group-difference in memory performance or amyloid-beta between the intervention and control group. However, the magnitude of PLAS-induced physiological responses were associated with memory performance up to 3 months post intervention and beneficial changes in plasma amyloid. Results were exclusive to the intervention group. DISCUSSION Multi-night PLAS is associated with long-lasting benefits in memory and metabolite clearance in older adults, rendering PLAS a promising tool to build upon and develop long-term protocols for the prevention of cognitive decline.
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Affiliation(s)
- Marina Wunderlin
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
- Graduate School for Health Sciences, University of Bern, 3012 Bern, Switzerland
| | - Céline Jacqueline Zeller
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
- Graduate School for Health Sciences, University of Bern, 3012 Bern, Switzerland
| | - Samira Rafaela Senti
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
| | - Kristoffer Daniel Fehér
- University Hospital of Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
| | - Debora Suppiger
- Department of Neonatology, University Hospital Zurich and University of Zurich, 8006 Zürich, Switzerland
| | - Patric Wyss
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
| | - Thomas Koenig
- University Hospital of Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
| | - Charlotte Elisabeth Teunissen
- Neurochemistry Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, Neurodegeneration, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
| | - Christoph Nissen
- University Hospital of Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
- Division of Psychiatric Specialties, Geneva University Hospitals (HUG), 1205 Geneva, Switzerland
| | - Stefan Klöppel
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
| | - Marc Alain Züst
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, 3000 Bern, Switzerland
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5
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Klar P, Çatal Y, Fogel S, Jocham G, Langner R, Owen AM, Northoff G. Auditory inputs modulate intrinsic neuronal timescales during sleep. Commun Biol 2023; 6:1180. [PMID: 37985812 PMCID: PMC10661171 DOI: 10.1038/s42003-023-05566-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 11/09/2023] [Indexed: 11/22/2023] Open
Abstract
Functional magnetic resonance imaging (fMRI) studies have demonstrated that intrinsic neuronal timescales (INT) undergo modulation by external stimulation during consciousness. It remains unclear if INT keep the ability for significant stimulus-induced modulation during primary unconscious states, such as sleep. This fMRI analysis addresses this question via a dataset that comprises an awake resting-state plus rest and stimulus states during sleep. We analyzed INT measured via temporal autocorrelation supported by median frequency (MF) in the frequency-domain. Our results were replicated using a biophysical model. There were two main findings: (1) INT prolonged while MF decreased from the awake resting-state to the N2 resting-state, and (2) INT shortened while MF increased during the auditory stimulus in sleep. The biophysical model supported these results by demonstrating prolonged INT in slowed neuronal populations that simulate the sleep resting-state compared to an awake state. Conversely, under sine wave input simulating the stimulus state during sleep, the model's regions yielded shortened INT that returned to the awake resting-state level. Our results highlight that INT preserve reactivity to stimuli in states of unconsciousness like sleep, enhancing our understanding of unconscious brain dynamics and their reactivity to stimuli.
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Affiliation(s)
- Philipp Klar
- Faculty of Mathematics and Natural Sciences, Institute of Experimental Psychology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.
- Institute of Neuroscience and Medicine, Brain & Behaviour (INM-7), Research Centre Jülich, Jülich, Germany.
| | - Yasir Çatal
- The Royal's Institute of Mental Health Research & University of Ottawa, Brain and Mind Research Institute, Centre for Neural Dynamics, Faculty of Medicine, University of Ottawa, 145 Carling Avenue, Room 6435, Ottawa, ON, K1Z 7K4, Canada
| | - Stuart Fogel
- Sleep Unit, University of Ottawa Institute of Mental Health Research at The Royal, K1Z 7K4, Ottawa, ON, Canada
| | - Gerhard Jocham
- Faculty of Mathematics and Natural Sciences, Institute of Experimental Psychology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Robert Langner
- Institute of Neuroscience and Medicine, Brain & Behaviour (INM-7), Research Centre Jülich, Jülich, Germany
- Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Adrian M Owen
- Departments of Physiology and Pharmacology and Psychology, Western University, London, ON, N6A 5B7, Canada
| | - Georg Northoff
- The Royal's Institute of Mental Health Research & University of Ottawa, Brain and Mind Research Institute, Centre for Neural Dynamics, Faculty of Medicine, University of Ottawa, 145 Carling Avenue, Room 6435, Ottawa, ON, K1Z 7K4, Canada
- Centre for Cognition and Brain Disorders, Hangzhou Normal University, Tianmu Road 305, Hangzhou, Zhejiang Province, 310013, China
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6
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Esfahani MJ, Farboud S, Ngo HVV, Schneider J, Weber FD, Talamini LM, Dresler M. Closed-loop auditory stimulation of sleep slow oscillations: Basic principles and best practices. Neurosci Biobehav Rev 2023; 153:105379. [PMID: 37660843 DOI: 10.1016/j.neubiorev.2023.105379] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/05/2023]
Abstract
Sleep is essential for our physical and mental well-being. During sleep, despite the paucity of overt behavior, our brain remains active and exhibits a wide range of coupled brain oscillations. In particular slow oscillations are characteristic for sleep, however whether they are directly involved in the functions of sleep, or are mere epiphenomena, is not yet fully understood. To disentangle the causality of these relationships, experiments utilizing techniques to detect and manipulate sleep oscillations in real-time are essential. In this review, we first overview the theoretical principles of closed-loop auditory stimulation (CLAS) as a method to study the role of slow oscillations in the functions of sleep. We then describe technical guidelines and best practices to perform CLAS and analyze results from such experiments. We further provide an overview of how CLAS has been used to investigate the causal role of slow oscillations in various sleep functions. We close by discussing important caveats, open questions, and potential topics for future research.
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Affiliation(s)
| | - Soha Farboud
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, the Netherlands
| | - Hong-Viet V Ngo
- Department of Psychology, University of Essex, United Kingdom; Department of Psychology, University of Lübeck, Germany; Center for Brain, Behaviour and Metabolism, University of Lübeck, Germany
| | - Jules Schneider
- Department of Psychiatry and Psychotherapy, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany; Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Frederik D Weber
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, the Netherlands; Department of Sleep and Cognition, Netherlands Institute for Neuroscience, an institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
| | - Lucia M Talamini
- Department of Psychology, University of Amsterdam, Amsterdam, the Netherlands; Amsterdam Brain and Cognition, University of Amsterdam, Amsterdam, the Netherlands
| | - Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, the Netherlands.
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7
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Fehér KD, Omlin X, Tarokh L, Schneider CL, Morishima Y, Züst MA, Wunderlin M, Koenig T, Hertenstein E, Ellenberger B, Ruch S, Schmidig F, Mikutta C, Trinca E, Senn W, Feige B, Klöppel S, Nissen C. Feasibility, efficacy, and functional relevance of automated auditory closed-loop suppression of slow-wave sleep in humans. J Sleep Res 2023:e13846. [PMID: 36806335 DOI: 10.1111/jsr.13846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/22/2022] [Accepted: 01/23/2023] [Indexed: 02/22/2023]
Abstract
Slow-wave sleep (SWS) is a fundamental physiological process, and its modulation is of interest for basic science and clinical applications. However, automatised protocols for the suppression of SWS are lacking. We describe the development of a novel protocol for the automated detection (based on the whole head topography of frontal slow waves) and suppression of SWS (through closed-loop modulated randomised pulsed noise), and assessed the feasibility, efficacy and functional relevance compared to sham stimulation in 15 healthy young adults in a repeated-measure sleep laboratory study. Auditory compared to sham stimulation resulted in a highly significant reduction of SWS by 30% without affecting total sleep time. The reduction of SWS was associated with an increase in lighter non-rapid eye movement sleep and a shift of slow-wave activity towards the end of the night, indicative of a homeostatic response and functional relevance. Still, cumulative slow-wave activity across the night was significantly reduced by 23%. Undisturbed sleep led to an evening to morning reduction of wake electroencephalographic theta activity, thought to reflect synaptic downscaling during SWS, while suppression of SWS inhibited this dissipation. We provide evidence for the feasibility, efficacy, and functional relevance of a novel fully automated protocol for SWS suppression based on auditory closed-loop stimulation. Future work is needed to further test for functional relevance and potential clinical applications.
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Affiliation(s)
- Kristoffer D Fehér
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,Division of Psychiatric Specialties, Geneva University Hospitals (HUG), Geneva, Switzerland
| | - Ximena Omlin
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,Division of Psychiatric Specialties, Geneva University Hospitals (HUG), Geneva, Switzerland
| | - Leila Tarokh
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Carlotta L Schneider
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Yosuke Morishima
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Marc A Züst
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Marina Wunderlin
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,Department of Social Neuroscience and Social Psychology, Institute of Psychology, University of Bern, Bern, Switzerland
| | - Thomas Koenig
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Elisabeth Hertenstein
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | | | - Simon Ruch
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University Hospital and University of Tübingen, Tübingen, Germany
| | - Flavio Schmidig
- Cognitive Neuroscience of Memory and Consciousness, Institute of Psychology, University of Bern, Bern, Switzerland
| | - Christian Mikutta
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,Privatklinik Meiringen, Meiringen, Switzerland
| | - Ersilia Trinca
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Walter Senn
- Institute of Physiology, University of Bern, Bern, Switzerland
| | - Bernd Feige
- University of Freiburg Medical Center, Freiburg, Germany
| | - Stefan Klöppel
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Christoph Nissen
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,Division of Psychiatric Specialties, Geneva University Hospitals (HUG), Geneva, Switzerland
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8
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Zeller CJ, Züst MA, Wunderlin M, Nissen C, Klöppel S. The promise of portable remote auditory stimulation tools to enhance slow-wave sleep and prevent cognitive decline. J Sleep Res 2023:e13818. [PMID: 36631001 DOI: 10.1111/jsr.13818] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 01/13/2023]
Abstract
Dementia is the seventh leading cause of mortality, and a major source of disability and dependency in older individuals globally. Cognitive decline (and, to a lesser extent, normal ageing) are associated with sleep fragmentation and loss of slow-wave sleep. Evidence suggests a bidirectional causal link between these losses. Phase-locked auditory stimulation has emerged as a promising non-invasive tool to enhance slow-wave sleep, potentially ameliorating cognitive decline. In laboratory settings, auditory stimulation is usually supervised by trained experts. Different algorithms (simple amplitude thresholds, topographic correlation, sine-wave fitting, phase-locked loop, and phase vocoder) are used to precisely target auditory stimulation to a desired phase of the slow wave. While all algorithms work well in younger adults, the altered sleep physiology of older adults and particularly those with neurodegenerative disorders requires a tailored approach that can adapt to older adults' fragmented sleep and reduced amplitudes of slow waves. Moreover, older adults might require a continuous intervention that is not feasible in laboratory settings. Recently, several auditory stimulation-capable portable devices ('Dreem®', 'SmartSleep®' and 'SleepLoop®') have been developed. We discuss these three devices regarding their potential as tools for science, and as clinical remote-intervention tools to combat cognitive decline. Currently, SleepLoop® shows the most promise for scientific research in older adults due to high transparency and customizability but is not commercially available. Studies evaluating down-stream effects on cognitive abilities, especially in patient populations, are required before a portable auditory stimulation device can be recommended as a clinical preventative remote-intervention tool.
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Affiliation(s)
- Céline J Zeller
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Marc A Züst
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Marina Wunderlin
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Christoph Nissen
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,Division of Psychiatric Specialties, Geneva University Hospitals (HUG), Geneva, Switzerland
| | - Stefan Klöppel
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
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