1
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Jones AM, Itti L, Sheth BR. Expert-level sleep staging using an electrocardiography-only feed-forward neural network. Comput Biol Med 2024; 176:108545. [PMID: 38749325 DOI: 10.1016/j.compbiomed.2024.108545] [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: 11/13/2023] [Revised: 04/05/2024] [Accepted: 04/28/2024] [Indexed: 05/31/2024]
Abstract
Reliable classification of sleep stages is crucial in sleep medicine and neuroscience research for providing valuable insights, diagnoses, and understanding of brain states. The current gold standard method for sleep stage classification is polysomnography (PSG). Unfortunately, PSG is an expensive and cumbersome process involving numerous electrodes, often conducted in an unfamiliar clinic and annotated by a professional. Although commercial devices like smartwatches track sleep, their performance is well below PSG. To address these disadvantages, we present a feed-forward neural network that achieves gold-standard levels of agreement using only a single lead of electrocardiography (ECG) data. Specifically, the median five-stage Cohen's kappa is 0.725 on a large, diverse dataset of 5 to 90-year-old subjects. Comparisons with a comprehensive meta-analysis of between-human inter-rater agreement confirm the non-inferior performance of our model. Finally, we developed a novel loss function to align the training objective with Cohen's kappa. Our method offers an inexpensive, automated, and convenient alternative for sleep stage classification-further enhanced by a real-time scoring option. Cardiosomnography, or a sleep study conducted with ECG only, could take expert-level sleep studies outside the confines of clinics and laboratories and into realistic settings. This advancement democratizes access to high-quality sleep studies, considerably enhancing the field of sleep medicine and neuroscience. It makes less-expensive, higher-quality studies accessible to a broader community, enabling improved sleep research and more personalized, accessible sleep-related healthcare interventions.
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Affiliation(s)
- Adam M Jones
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA.
| | - Laurent Itti
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Bhavin R Sheth
- Department of Electrical & Computer Engineering, University of Houston, Houston, TX, USA; Center for NeuroEngineering and Cognitive Systems, University of Houston, Houston, TX, USA
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2
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Van den Bulcke L, Van Den Bossche M. Unraveling the potential of acoustic stimulation to enhance slow-wave sleep in Alzheimer's disease: implications and pathways forward. J Clin Sleep Med 2024; 20:1023. [PMID: 38459871 PMCID: PMC11145057 DOI: 10.5664/jcsm.11124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 03/05/2024] [Indexed: 03/11/2024]
Affiliation(s)
- Laura Van den Bulcke
- Geriatric Psychiatry, University Psychiatric Center KU Leuven, Leuven, Belgium
- Neuropsychiatry, Research Group Psychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Maarten Van Den Bossche
- Geriatric Psychiatry, University Psychiatric Center KU Leuven, Leuven, Belgium
- Neuropsychiatry, Research Group Psychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium
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3
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Hebron H, Lugli B, Dimitrova R, Jaramillo V, Yeh LR, Rhodes E, Grossman N, Dijk DJ, Violante IR. A closed-loop auditory stimulation approach selectively modulates alpha oscillations and sleep onset dynamics in humans. PLoS Biol 2024; 22:e3002651. [PMID: 38889194 PMCID: PMC11185466 DOI: 10.1371/journal.pbio.3002651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 05/01/2024] [Indexed: 06/20/2024] Open
Abstract
Alpha oscillations play a vital role in managing the brain's resources, inhibiting neural activity as a function of their phase and amplitude, and are changed in many brain disorders. Developing minimally invasive tools to modulate alpha activity and identifying the parameters that determine its response to exogenous modulators is essential for the implementation of focussed interventions. We introduce Alpha Closed-Loop Auditory Stimulation (αCLAS) as an EEG-based method to modulate and investigate these brain rhythms in humans with specificity and selectivity, using targeted auditory stimulation. Across a series of independent experiments, we demonstrate that αCLAS alters alpha power, frequency, and connectivity in a phase, amplitude, and topography-dependent manner. Using single-pulse-αCLAS, we show that the effects of auditory stimuli on alpha oscillations can be explained within the theoretical framework of oscillator theory and a phase-reset mechanism. Finally, we demonstrate the functional relevance of our approach by showing that αCLAS can interfere with sleep onset dynamics in a phase-dependent manner.
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Affiliation(s)
- Henry Hebron
- School of Psychology, University of Surrey, Guildford, United Kingdom
- Surrey Sleep Research Centre, University of Surrey, Guildford, United Kingdom
- UK Dementia Research Institute Care Research and Technology Centre, Imperial College London and the University of Surrey, Guildford, United Kingdom
| | - Beatrice Lugli
- School of Psychology, University of Surrey, Guildford, United Kingdom
| | - Radost Dimitrova
- School of Psychology, University of Surrey, Guildford, United Kingdom
| | - Valeria Jaramillo
- School of Psychology, University of Surrey, Guildford, United Kingdom
- Surrey Sleep Research Centre, University of Surrey, Guildford, United Kingdom
- UK Dementia Research Institute Care Research and Technology Centre, Imperial College London and the University of Surrey, Guildford, United Kingdom
| | - Lisa R. Yeh
- School of Psychology, University of Surrey, Guildford, United Kingdom
| | - Edward Rhodes
- Department of Brain Sciences, Imperial College London, London, United Kingdom
- UK Dementia Research Institute Imperial College London, United Kingdom
| | - Nir Grossman
- Department of Brain Sciences, Imperial College London, London, United Kingdom
- UK Dementia Research Institute Imperial College London, United Kingdom
| | - Derk-Jan Dijk
- Surrey Sleep Research Centre, University of Surrey, Guildford, United Kingdom
- UK Dementia Research Institute Care Research and Technology Centre, Imperial College London and the University of Surrey, Guildford, United Kingdom
| | - Ines R. Violante
- School of Psychology, University of Surrey, Guildford, United Kingdom
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4
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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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5
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Pelentritou A, Pfeiffer C, Schwartz S, De Lucia M. Cardio-audio synchronization elicits neural and cardiac surprise responses in human wakefulness and sleep. Commun Biol 2024; 7:226. [PMID: 38396068 PMCID: PMC10891147 DOI: 10.1038/s42003-024-05895-2] [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: 08/02/2023] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
The human brain can encode auditory regularities with fixed sound-to-sound intervals and with sound onsets locked to cardiac inputs. Here, we investigated auditory and cardio-audio regularity encoding during sleep, when bodily and environmental stimulus processing may be altered. Using electroencephalography and electrocardiography in healthy volunteers (N = 26) during wakefulness and sleep, we measured the response to unexpected sound omissions within three regularity conditions: synchronous, where sound and heartbeat are temporally coupled, isochronous, with fixed sound-to-sound intervals, and a control condition without regularity. Cardio-audio regularity encoding manifested as a heartbeat deceleration upon omissions across vigilance states. The synchronous and isochronous sequences induced a modulation of the omission-evoked neural response in wakefulness and N2 sleep, the former accompanied by background oscillatory activity reorganization. The violation of cardio-audio and auditory regularity elicits cardiac and neural responses across vigilance states, laying the ground for similar investigations in altered consciousness states such as coma and anaesthesia.
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Affiliation(s)
- Andria Pelentritou
- Laboratoire de Recherche en Neuroimagerie (LREN), Lausanne University Hospital and University of Lausanne, 1011, Lausanne, Switzerland.
| | - Christian Pfeiffer
- Robotics and Perception Group, University of Zurich, 8050, Zurich, Switzerland
| | - Sophie Schwartz
- Department of Neuroscience, Faculty of Medicine, University of Geneva, 1211, Geneva, Switzerland
- Swiss Center for Affective Sciences, University of Geneva, 1202, Geneva, Switzerland
| | - Marzia De Lucia
- Laboratoire de Recherche en Neuroimagerie (LREN), Lausanne University Hospital and University of Lausanne, 1011, Lausanne, Switzerland.
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6
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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: 0] [Impact Index Per Article: 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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7
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Baxter BS, Mylonas D, Kwok KS, Talbot CE, Patel R, Zhu L, Vangel M, Stickgold R, Manoach DS. The effects of closed-loop auditory stimulation on sleep oscillatory dynamics in relation to motor procedural memory consolidation. Sleep 2023; 46:zsad206. [PMID: 37531587 PMCID: PMC11009689 DOI: 10.1093/sleep/zsad206] [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: 01/17/2023] [Revised: 05/13/2023] [Indexed: 08/04/2023] Open
Abstract
STUDY OBJECTIVES Healthy aging and many disorders show reduced sleep-dependent memory consolidation and corresponding alterations in non-rapid eye movement sleep oscillations. Yet sleep physiology remains a relatively neglected target for improving memory. We evaluated the effects of closed-loop auditory stimulation during sleep (CLASS) on slow oscillations (SOs), sleep spindles, and their coupling, all in relation to motor procedural memory consolidation. METHODS Twenty healthy young adults had two afternoon naps: one with auditory stimulation during SO upstates and another with no stimulation. Twelve returned for a third nap with stimulation at variable times in relation to SO upstates. In all sessions, participants trained on the motor sequence task prior to napping and were tested afterward. RESULTS Relative to epochs with no stimulation, upstate stimuli disrupted sleep and evoked SOs, spindles, and SO-coupled spindles. Stimuli that successfully evoked oscillations were delivered closer to the peak of the SO upstate and when spindle power was lower than stimuli that failed to evoke oscillations. Across conditions, participants showed similar significant post-nap performance improvement that correlated with the density of SO-coupled spindles. CONCLUSIONS Despite its strong effects on sleep physiology, CLASS failed to enhance motor procedural memory. Our findings suggest methods to overcome this failure, including better sound calibration to preserve sleep continuity and the use of real-time predictive algorithms to more precisely target SO upstates and to avoid disrupting endogenous SO-coupled spindles and their mnemonic function. They motivate continued development of CLASS as an intervention to manipulate sleep oscillatory dynamics and improve memory.
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Affiliation(s)
- Bryan S Baxter
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Dimitrios Mylonas
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Kristi S Kwok
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Christine E Talbot
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Rudra Patel
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lin Zhu
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Mark Vangel
- Department of Biostatistics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Robert Stickgold
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Dara S Manoach
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
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8
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Kavoosi A, Mitchell MP, Kariyawasam R, Fleming JE, Lewis P, Johansen-Berg H, Cagnan H, Denison T. MorpheusNet: Resource efficient sleep stage classifier for embedded on-line systems. CONFERENCE PROCEEDINGS. IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS 2023; 2023:2315-2320. [PMID: 38384281 PMCID: PMC7615658 DOI: 10.1109/smc53992.2023.10394274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Sleep Stage Classification (SSC) is a labor-intensive task, requiring experts to examine hours of electrophysiological recordings for manual classification. This is a limiting factor when it comes to leveraging sleep stages for therapeutic purposes. With increasing affordability and expansion of wearable devices, automating SSC may enable deployment of sleep-based therapies at scale. Deep Learning has gained increasing attention as a potential method to automate this process. Previous research has shown accuracy comparable to manual expert scores. However, previous approaches require sizable amount of memory and computational resources. This constrains the ability to classify in real time and deploy models on the edge. To address this gap, we aim to provide a model capable of predicting sleep stages in real-time, without requiring access to external computational sources (e.g., mobile phone, cloud). The algorithm is power efficient to enable use on embedded battery powered systems. Our compact sleep stage classifier can be deployed on most off-the-shelf microcontrollers (MCU) with constrained hardware settings. This is due to the memory footprint of our approach requiring significantly fewer operations. The model was tested on three publicly available data bases and achieved performance comparable to the state of the art, whilst reducing model complexity by orders of magnitude (up to 280 times smaller compared to state of the art). We further optimized the model with quantization of parameters to 8 bits with only an average drop of 0.95% in accuracy. When implemented in firmware, the quantized model achieves a latency of 1.6 seconds on an Arm Cortex-M4 processor, allowing its use for on-line SSC-based therapies.
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Affiliation(s)
- Ali Kavoosi
- MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Morgan P. Mitchell
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | | | - John E. Fleming
- MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Penny Lewis
- Brain Research Imaging Centre, Cardiff University, Cardiff, UK
| | - Heidi Johansen-Berg
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Hayriye Cagnan
- MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Timothy Denison
- MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK
- Department of Engineering Sciences, University of Oxford, Oxford, UK
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9
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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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10
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LaGoy AD, Kubala AG, Deering S, Germain A, Markwald RR. Dawn of a New Dawn: Advances in Sleep Health to Optimize Performance. Sleep Med Clin 2023; 18:361-371. [PMID: 37532375 DOI: 10.1016/j.jsmc.2023.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Optimal sleep health is a critical component to high-level performance. In populations such as the military, public service (eg, firefighters), and health care, achieving optimal sleep health is difficult and subsequently deficiencies in sleep health may lead to performance decrements. However, advances in sleep monitoring technologies and mitigation strategies for poor sleep health show promise for further ecological scientific investigation within these populations. The current review briefly outlines the relationship between sleep health and performance as well as current advances in behavioral and technological approaches to improving sleep health for performance.
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Affiliation(s)
- Alice D LaGoy
- Sleep, Tactical Efficiency, and Endurance Laboratory, Warfighter Performance Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., San Diego, CA, USA
| | - Andrew G Kubala
- Sleep, Tactical Efficiency, and Endurance Laboratory, Warfighter Performance Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., San Diego, CA, USA
| | - Sean Deering
- Sleep, Tactical Efficiency, and Endurance Laboratory, Warfighter Performance Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA; Leidos, Inc., San Diego, CA, USA
| | | | - Rachel R Markwald
- Sleep, Tactical Efficiency, and Endurance Laboratory, Warfighter Performance Department, Naval Health Research Center, 140 Sylvester Road, San Diego, CA 92106, USA.
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11
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Abdellahi MEA, Koopman ACM, Treder MS, Lewis PA. Targeting targeted memory reactivation: Characteristics of cued reactivation in sleep. Neuroimage 2023; 266:119820. [PMID: 36535324 DOI: 10.1016/j.neuroimage.2022.119820] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/16/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Targeted memory reactivation (TMR) is a technique in which sensory cues associated with memories during wake are used to trigger memory reactivation during subsequent sleep. The characteristics of such cued reactivation, and the optimal placement of TMR cues, remain to be determined. We built an EEG classification pipeline that discriminated reactivation of right- and left-handed movements and found that cues which fall on the up-going transition of the slow oscillation (SO) are more likely to elicit a classifiable reactivation. We also used a novel machine learning pipeline to predict the likelihood of eliciting a classifiable reactivation after each TMR cue using the presence of spindles and features of SOs. Finally, we found that reactivations occurred either immediately after the cue or one second later. These findings greatly extend our understanding of memory reactivation and pave the way for development of wearable technologies to efficiently enhance memory through cueing in sleep.
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Affiliation(s)
- Mahmoud E A Abdellahi
- School of Psychology, Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff CF24 4HQ, United Kingdom.
| | - Anne C M Koopman
- School of Psychology, Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff CF24 4HQ, United Kingdom
| | - Matthias S Treder
- School of Computer Science and Informatics, Cardiff University, Cardiff CF24 3AA, United Kingdom
| | - Penelope A Lewis
- School of Psychology, Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff CF24 4HQ, United Kingdom
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12
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Roebber JK, Lewis PA, Crunelli V, Navarrete M, Hamandi K. Effects of Anti-Seizure Medication on Sleep Spindles and Slow Waves in Drug-Resistant Epilepsy. Brain Sci 2022; 12:1288. [PMID: 36291222 PMCID: PMC9599317 DOI: 10.3390/brainsci12101288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/15/2022] [Accepted: 09/20/2022] [Indexed: 09/23/2023] Open
Abstract
There is a close bidirectional relationship between sleep and epilepsy. Anti-seizure medications (ASM) act to reduce seizure frequency but can also impact sleep; this remains a relatively unexplored field given the importance of sleep on seizure occurrence, memory consolidation, and quality of life. We compared the effect of poly-ASM treatment on a night of sleep compared to an unmedicated night in patients with drug-resistant epilepsy, where ASMs were withdrawn and later restored as part of their pre-surgical evaluation. Within-subject analysis between medicated and unmedicated nights showed ASMs increased spindle (11-16 Hz) power and decreased slow wave (0.1-2 Hz) amplitude. Spindles became less strongly coupled to slow waves in the ASM night compared to no-ASM night, with effects to both the phase and strength of coupling and correlated with slow wave reduction. These effects were not seen in age-matched controls from the same unit where ASMs were not changed between two nights. Overall, we found that ASM polytherapy not only changed specific sleep waveforms, but also the fine interplay of spindle/slow wave coupling. Since these sleep oscillations impact both seizure occurrence and memory consolidation, our findings provide evidence towards a decoupling impact of ASMs on sleep that should be considered in future studies of sleep and memory disruption in people with epilepsy.
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Affiliation(s)
- Jennifer K. Roebber
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd., Cardiff CF24 4HQ, UK
- The Welsh Epilepsy Unit, Department of Neurology, University Hospital of Wales, Heath Park, Cardiff CF14 4XN, UK
| | - Penelope A. Lewis
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd., Cardiff CF24 4HQ, UK
| | - Vincenzo Crunelli
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff CF10 3AX, UK
| | - Miguel Navarrete
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd., Cardiff CF24 4HQ, UK
| | - Khalid Hamandi
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd., Cardiff CF24 4HQ, UK
- The Welsh Epilepsy Unit, Department of Neurology, University Hospital of Wales, Heath Park, Cardiff CF14 4XN, UK
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13
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Abstract
Over the past few decades, the importance of sleep has become increasingly recognized for many physiologic functions, including cognition. Many studies have reported the deleterious effect of sleep loss or sleep disruption on cognitive performance. Beyond ensuring adequate sleep quality and duration, discovering methods to enhance sleep to augment its restorative effects is important to improve learning in many populations, such as the military, students, age-related cognitive decline, and cognitive disorders.
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Affiliation(s)
- Roneil G Malkani
- Division of Sleep Medicine, Department of Neurology, Center for Circadian and Sleep Medicine, Northwestern University Feinberg School of Medicine, 710 North Lake Shore Drive, Suite 525, Chicago, IL 60611, USA; Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA.
| | - Phyllis C Zee
- Division of Sleep Medicine, Department of Neurology, Center for Circadian and Sleep Medicine, Northwestern University Feinberg School of Medicine, 710 North Lake Shore Drive, Suite 520, Chicago, IL 60611, USA
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14
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Weinhold SL, Lechinger J, Timm N, Hansen A, Ngo HVV, Göder R. Auditory stimulation in-phase with slow oscillations to enhance overnight memory consolidation in patients with schizophrenia? J Sleep Res 2022; 31:e13636. [PMID: 35686351 DOI: 10.1111/jsr.13636] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 03/24/2022] [Accepted: 04/27/2022] [Indexed: 11/27/2022]
Abstract
Sleep-dependent memory consolidation is disturbed in patients with schizophrenia, who furthermore show reductions in sleep spindles and probably also in delta power during sleep. The memory dysfunction in these patients is one of the strongest markers for worse long-term functional outcome. However, therapeutic interventions to normalise memory functions, e.g., with medication, still do not exist. Against this backdrop, we investigated to what extent a non-invasive approach enhancing sleep with real-time auditory stimulation in-phase with slow oscillations might affect overnight memory consolidation in patients with schizophrenia. To this end, we examined 18 patients with stably medicated schizophrenia in a double-blinded sham-controlled design. Memory performance was assessed by a verbal (word list) and a non-verbal (complex figure) declarative memory task. In comparison to a sham condition without auditory stimuli, we found that in patients with schizophrenia, auditory stimulation evokes an electrophysiological response similar to that in healthy participants leading to an increase in slow wave and temporally coupled sleep spindle activity during stimulation. Despite this finding, patients did not show any beneficial effect on the overnight change in memory performance by stimulation. Although the stimulation in our study did not improve the patient's memory, the electrophysiological response gives hope that auditory stimulation could enable us to provide better treatment for sleep-related detriments in these patients in the future.
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Affiliation(s)
- Sara Lena Weinhold
- Department of Psychiatry and Psychotherapy (ZIP), University Hospital Schleswig-Holstein (UKSH), Kiel, Germany
| | - Julia Lechinger
- Department of Psychiatry and Psychotherapy (ZIP), University Hospital Schleswig-Holstein (UKSH), Kiel, Germany
| | - Nele Timm
- Department of Psychiatry and Psychotherapy (ZIP), University Hospital Schleswig-Holstein (UKSH), Kiel, Germany
| | - Anja Hansen
- Department of Psychiatry and Psychotherapy (ZIP), University Hospital Schleswig-Holstein (UKSH), Kiel, Germany
| | - Hong-Viet V Ngo
- Department of Psychology, University of Lübeck, Lübeck, Germany
| | - Robert Göder
- Department of Psychiatry and Psychotherapy (ZIP), University Hospital Schleswig-Holstein (UKSH), Kiel, Germany
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15
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Hoedlmoser K, Peigneux P, Rauchs G. Recent advances in memory consolidation and information processing during sleep. J Sleep Res 2022; 31:e13607. [DOI: 10.1111/jsr.13607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 03/25/2022] [Accepted: 03/25/2022] [Indexed: 12/20/2022]
Affiliation(s)
- Kerstin Hoedlmoser
- Department of Psychology, Centre for Cognitive Neuroscience (CCNS), Laboratory for “Sleep, Cognition and Consciousness Research” University of Salzburg Salzburg Austria
| | - Philippe Peigneux
- UR2NF – Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN – Centre for Research in Cognition and Neurosciences and UNI – ULB Neuroscience Institute Bruxelles Belgium
| | - Géraldine Rauchs
- UNICAEN, INSERM, U1237, PhIND “Physiopathology and Imaging of Neurological Disorders”, Institut Blood and Brain @ Caen‐Normandie Normandie Univ Caen France
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16
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Navarrete M, Arthur S, Treder MS, Lewis PA. Ongoing neural oscillations predict the post-stimulus outcome of closed loop auditory stimulation during slow-wave sleep. Neuroimage 2022; 253:119055. [PMID: 35276365 DOI: 10.1016/j.neuroimage.2022.119055] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 02/26/2022] [Accepted: 03/01/2022] [Indexed: 10/18/2022] Open
Abstract
Large slow oscillations (SO, 0.5-2 Hz) characterise slow-wave sleep and are crucial to memory consolidation and other physiological functions. Manipulating slow oscillations may enhance sleep and memory, as well as benefitting the immune system. Closed-loop auditory stimulation (CLAS) has been demonstrated to increase the SO amplitude and to boost fast sleep spindle activity (11-16 Hz). Nevertheless, not all such stimuli are effective in evoking SOs, even when they are precisely phase locked. Here, we studied what factors of the ongoing activity patterns may help to determine what oscillations to stimulate to effectively enhance SOs or SO-locked spindle activity. Hence, we trained classifiers using the morphological characteristics of the ongoing SO, as measured by electroencephalography (EEG), to predict whether stimulation would lead to a benefit in terms of the resulting SO and spindle amplitude. Separate classifiers were trained using trials from spontaneous control and stimulated datasets, and we evaluated their performance by applying them to held-out data both within and across conditions. We were able to predict both when large SOs occurred spontaneously, and whether a phase-locked auditory click effectively enlarged them with good accuracy for predicting the SO trough (∼70%) and SO peak values (∼80%). Also, we were able to predict when stimulation would elicit spindle activity with an accuracy of ∼60%. Finally, we evaluate the importance of the various SO features used to make these predictions. Our results offer new insight into SO and spindle dynamics and may suggest techniques for developing future methods for online optimization of stimulation.
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Affiliation(s)
- Miguel Navarrete
- Cardiff University Brain Research Imaging Center (CUBRIC), School of Psychology, Cardiff University, Maindy Rd, Cardiff CF24 4HQ, UK.
| | - Steven Arthur
- School of Computer Science and Informatics, Cardiff University, Queen's Buildings, 5 The Parade, Roath, Cardiff CF24 3AA, UK
| | - Matthias S Treder
- School of Computer Science and Informatics, Cardiff University, Queen's Buildings, 5 The Parade, Roath, Cardiff CF24 3AA, UK
| | - Penelope A Lewis
- Cardiff University Brain Research Imaging Center (CUBRIC), School of Psychology, Cardiff University, Maindy Rd, Cardiff CF24 4HQ, UK.
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17
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Wang JY, Heck KL, Born J, Ngo HVV, Diekelmann S. No difference between slow oscillation up- and down-state cueing for memory consolidation during sleep. J Sleep Res 2022; 31:e13562. [PMID: 35166422 DOI: 10.1111/jsr.13562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 11/30/2022]
Abstract
The beneficial effects of sleep for memory consolidation are assumed to rely on the reactivation of memories in conjunction with the coordinated interplay of sleep rhythms like slow oscillations and spindles. Specifically, slow oscillations are assumed to provide the temporal frame for spindles to occur in the slow oscillations up-states, enabling a redistribution of reactivated information within hippocampal-neocortical networks for long-term storage. Memory reactivation can also be triggered externally by presenting learning-associated cues (like odours or sounds) during sleep, but it is presently unclear whether there is an optimal time-window for the presentation of such cues in relation to the phase of the slow oscillations. In the present within-subject comparison, participants (n = 16) learnt word-pairs visually presented with auditory cues of the first syllable. These syllables were subsequently used for real-time cueing either in the up- or down-state of endogenous slow oscillations. Contrary to our hypothesis, we found differences in memory performance neither between up- and down-state cueing, nor between word-pairs that were cued versus uncued. In the up-state cueing condition, higher amounts of rapid eye movement sleep were associated with better memory for cued contents, whereas higher amounts of slow-wave sleep were associated with better memory for uncued contents. Evoked response analyses revealed signs of cue processing in both conditions. Interestingly, both up- and down-state cueing evoked a similar spindle response with the induced slow oscillations up-state at ~1000 ms post-cue. We speculate that our cueing procedure triggered generalised reactivation processes that facilitated the consolidation of both cued and uncued memories irrespective of the slow oscillation phase.
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Affiliation(s)
- Jing-Yi Wang
- Institute of Medical Psychology and Behavioral Neurobiology, University Tübingen, Tübingen, Germany.,State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Faculty of Psychology at Beijing Normal University, Beijing, China
| | - Katharina L Heck
- Institute of Medical Psychology and Behavioral Neurobiology, University Tübingen, Tübingen, Germany
| | - Jan Born
- Institute of Medical Psychology and Behavioral Neurobiology, University Tübingen, Tübingen, Germany.,Centre for Integrative Neuroscience, University Tübingen, Tübingen, Germany
| | - Hong-Viet V Ngo
- Department of Psychology, University of Lübeck, Lübeck, Germany
| | - Susanne Diekelmann
- Institute of Medical Psychology and Behavioral Neurobiology, University Tübingen, Tübingen, Germany.,Department of Psychiatry and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
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18
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Henao D, Navarrete M, Juez JY, Dinh H, Gómez R, Valderrama M, Le Van Quyen M. Auditory closed‐loop stimulation on sleep slow oscillations using in‐ear EEG sensors. J Sleep Res 2022; 31:e13555. [DOI: 10.1111/jsr.13555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 11/30/2022]
Affiliation(s)
- David Henao
- Department of Biomedical Engineering Universidad de Los Andes Bogotá D.C. Colombia
| | - Miguel Navarrete
- Department of Biomedical Engineering Universidad de Los Andes Bogotá D.C. Colombia
- Cardiff University Brain Research Imaging Centre (CUBRIC) School of Psychology Cardiff University Cardiff UK
| | - José Yesith Juez
- Department of Biomedical Engineering Universidad de Los Andes Bogotá D.C. Colombia
| | | | - Rodrigo Gómez
- Department of Biomedical Engineering Universidad de Los Andes Bogotá D.C. Colombia
| | - Mario Valderrama
- Department of Biomedical Engineering Universidad de Los Andes Bogotá D.C. Colombia
| | - Michel Le Van Quyen
- Laboratoire d’Imagerie Biomédicale (LIB) Inserm U1146/Sorbonne Université UMCR2/UMR7371 CNRS Paris France
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19
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Rakowska M, Abdellahi MEA, Bagrowska P, Navarrete M, Lewis PA. Long term effects of cueing procedural memory reactivation during NREM sleep. Neuroimage 2021; 244:118573. [PMID: 34537384 PMCID: PMC8591408 DOI: 10.1016/j.neuroimage.2021.118573] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 09/02/2021] [Accepted: 09/07/2021] [Indexed: 11/17/2022] Open
Abstract
A single night of TMR benefits procedural memories up to 10 days later. Spindle density and SO-spindle coupling strength increase immediately upon cue onset. Time spent in N2 but not N3 predicts cueing benefit.
Targeted memory reactivation (TMR) has recently emerged as a promising tool to manipulate and study the sleeping brain. Although the technique is developing rapidly, only a few studies have examined how the effects of TMR develop over time. Here, we use a bimanual serial reaction time task (SRTT) to investigate whether the difference between the cued and un-cued sequence of button presses persists long-term. We further explore the relationship between the TMR benefit and sleep spindles, as well as their coupling with slow oscillations. Our behavioural analysis shows better performance for the dominant hand. Importantly, there was a strong effect of TMR, with improved performance on the cued sequence after sleep. Closer examination revealed a significant benefit of TMR at 10 days post-encoding, but not 24 h or 6 weeks post-encoding. Time spent in stage 2, but not stage 3, of NREM sleep predicted cueing benefit. We also found a significant increase in spindle density and SO-spindle coupling during the cue period, when compared to the no-cue period. Together, our results demonstrate that TMR effects evolve over several weeks post-cueing, as well as emphasising the importance of stage 2, spindles and the SO-spindle coupling in procedural memory consolidation.
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Affiliation(s)
- Martyna Rakowska
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd, Cardiff CF24 4HQ, UK.
| | - Mahmoud E A Abdellahi
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd, Cardiff CF24 4HQ, UK
| | - Paulina Bagrowska
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd, Cardiff CF24 4HQ, UK
| | - Miguel Navarrete
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd, Cardiff CF24 4HQ, UK
| | - Penelope A Lewis
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Maindy Rd, Cardiff CF24 4HQ, UK
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20
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Beck J, Loretz E, Rasch B. Exposure to relaxing words during sleep promotes slow-wave sleep and subjective sleep quality. Sleep 2021; 44:zsab148. [PMID: 34115139 PMCID: PMC8598180 DOI: 10.1093/sleep/zsab148] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 05/07/2021] [Indexed: 12/14/2022] Open
Abstract
Our thoughts alter our sleep, but the underlying mechanisms are still unknown. We propose that mental processes are active to a greater or lesser extent during sleep and that this degree of activation affects our sleep depth. We examined this notion by activating the concept of "relaxation" during sleep using relaxation-related words in 50 healthy participants. In support of our hypothesis, playing relaxing words during non-rapid eye movement sleep extended the time spent in slow-wave sleep, increased power in the slow-wave activity band after the word cue, and abolished an asymmetrical sleep depth during the word presentation period. In addition, participants reported a higher sleep quality and elevated subjective alertness. Our results support the notion that the activation of mental concepts during sleep can influence sleep depth. They provide a basis for interventions using targeted activations to promote sleep depth and sleep quality to foster well-being and health.
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Affiliation(s)
- Jonas Beck
- Department of Psychology, University of Fribourg, Fribourg, Switzerland
| | - Erna Loretz
- The Siesta Group Schlafanalyse GmbH, Vienna, Austria
| | - Björn Rasch
- Department of Psychology, University of Fribourg, Fribourg, Switzerland
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21
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Wunderlin M, Züst MA, Hertenstein E, Fehér KD, Schneider CL, Klöppel S, Nissen C. Modulating overnight memory consolidation by acoustic stimulation during slow-wave sleep: a systematic review and meta-analysis. Sleep 2021; 44:6066545. [PMID: 33406249 DOI: 10.1093/sleep/zsaa296] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/12/2020] [Indexed: 12/18/2022] Open
Abstract
STUDY OBJECTIVES The low-frequency high-amplitude oscillations of slow-wave sleep (SWS) are considered to promote the consolidation of episodic memory. Previous research suggests that sleep slow waves can be entrained and enhanced by presenting short acoustic stimuli to the up-states of endogenous waves. Several studies have investigated the effects of these increases in slow-wave activity on overnight memory consolidation, with inconsistent results. The aim of this meta-analysis was to evaluate the accumulated evidence connecting acoustic stimulation during sleep to episodic memory consolidation. METHODS A systematic literature search was conducted in October 2020 using PubMed, Web of Science, and PsycInfo. The main study inclusion criteria were the application of acoustic slow wave enhancement in healthy participants and an assessment of pre- and post-sleep episodic memory performance. Effect sizes were pooled using a random-effects model. RESULTS A total of 10 primary studies with 11 experiments and 177 participants were included. Results showed a combined effect size (Hedges' g) of 0.25 (p = 0.07). Subgroup models based on young adults (n = 8), phase-locked stimulation approaches (n = 8), and their combination (n = 6) showed combined effect sizes of 0.31 (p = 0.051), 0.36 (p = 0.047), and 0.44 (p = 0.01), respectively. There was no indication of publication bias or bias in individual studies. CONCLUSIONS Acoustic enhancement of SWS tends to increase the overnight consolidation of episodic memory but effects remain small and-with the exception of subgroup models-at trend levels. Currently, the evidence is not sufficient to recommend the use of commercially available devices.
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Affiliation(s)
- Marina Wunderlin
- 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
| | - Elisabeth Hertenstein
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Kristoffer D Fehér
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Carlotta L Schneider
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - 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
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22
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Real-Time Excitation of Slow Oscillations during Deep Sleep Using Acoustic Stimulation. SENSORS 2021; 21:s21155169. [PMID: 34372405 PMCID: PMC8347755 DOI: 10.3390/s21155169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 11/20/2022]
Abstract
Slow-wave synchronous acoustic stimulation is a promising research and therapeutic tool. It is essential to clearly understand the principles of the synchronization methods, to know their performances and limitations, and, most importantly, to have a clear picture of the effect of stimulation on slow-wave activity (SWA). This paper covers the mentioned and currently missing parts of knowledge that are essential for the appropriate development of the method itself and future applications. Artificially streamed real sleep EEG data were used to quantitatively compare the two currently used real-time methods: the phase-locking loop (PLL) and the fixed-step stimulus in our own implementation. The fixed-step stimulation method was concluded to be more reliable and practically applicable compared to the PLL method. The sleep experiment with chronic insomnia patients in our sleep laboratory was analyzed in order to precisely characterize the effect of sound stimulation during deep sleep. We found that there is a significant phase synchronization of delta waves, which were shown to be the most sensitive metric of the effect of acoustic stimulation compared to commonly used averaged signal and power analyses. This finding may change the understanding of the effect and function of the SWA stimulation described in the literature.
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23
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Harrington MO, Cairney SA. Sounding It Out: Auditory Stimulation and Overnight Memory Processing. CURRENT SLEEP MEDICINE REPORTS 2021; 7:112-119. [PMID: 34722123 PMCID: PMC8550047 DOI: 10.1007/s40675-021-00207-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2021] [Indexed: 02/05/2023]
Abstract
Abstract
Purpose of Review
Auditory stimulation is a technique that can enhance neural oscillations linked to overnight memory consolidation. In this review, we evaluate the impacts of auditory stimulation on the neural oscillations of sleep and associated memory processes in a variety of populations.
Recent Findings
Cortical EEG recordings of slow-wave sleep (SWS) are characterised by two cardinal oscillations: slow oscillations (SOs) and sleep spindles. Auditory stimulation delivered in SWS enhances SOs and phase-coupled spindle activity in healthy children and adults, children with ADHD, adults with mild cognitive impairment and patients with major depression. Under certain conditions, auditory stimulation bolsters the benefits of SWS for memory consolidation, although further work is required to fully understand the factors affecting stimulation-related memory gains. Recent work has turned to rapid eye movement (REM) sleep, demonstrating that auditory stimulation can be used to manipulate REM sleep theta oscillations.
Summary
Auditory stimulation enhances oscillations linked to overnight memory processing and shows promise as a technique for enhancing the memory benefits of sleep.
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24
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Affiliation(s)
- Simon Ruch
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University Hospital and University of Tuebingen, Germany
| | - Michael Valiadis
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University Hospital and University of Tuebingen, Germany
| | - Alireza Gharabaghi
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University Hospital and University of Tuebingen, Germany
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25
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Torres FA, Orio P, Escobar MJ. Selection of stimulus parameters for enhancing slow wave sleep events with a neural-field theory thalamocortical model. PLoS Comput Biol 2021; 17:e1008758. [PMID: 34329289 PMCID: PMC8357165 DOI: 10.1371/journal.pcbi.1008758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 08/11/2021] [Accepted: 05/28/2021] [Indexed: 11/30/2022] Open
Abstract
Slow-wave sleep cortical brain activity, conformed by slow-oscillations and sleep spindles, plays a key role in memory consolidation. The increase of the power of the slow-wave events, obtained by auditory sensory stimulation, positively correlates with memory consolidation performance. However, little is known about the experimental protocol maximizing this effect, which could be induced by the power of slow-oscillation, the number of sleep spindles, or the timing of both events' co-occurrence. Using a mean-field model of thalamocortical activity, we studied the effect of several stimulation protocols, varying the pulse shape, duration, amplitude, and frequency, as well as a target-phase using a closed-loop approach. We evaluated the effect of these parameters on slow-oscillations (SO) and sleep-spindles (SP), considering: (i) the power at the frequency bands of interest, (ii) the number of SO and SP, (iii) co-occurrences between SO and SP, and (iv) synchronization of SP with the up-peak of the SO. The first three targets are maximized using a decreasing ramp pulse with a pulse duration of 50 ms. Also, we observed a reduction in the number of SO when increasing the stimulus energy by rising its amplitude. To assess the target-phase parameter, we applied closed-loop stimulation at 0°, 45°, and 90° of the phase of the narrow-band filtered ongoing activity, at 0.85 Hz as central frequency. The 0° stimulation produces better results in the power and number of SO and SP than the rhythmic or random stimulation. On the other hand, stimulating at 45° or 90° change the timing distribution of spindles centers but with fewer co-occurrences than rhythmic and 0° phase. Finally, we propose the application of closed-loop stimulation at the rising zero-cross point using pulses with a decreasing ramp shape and 50 ms of duration for future experimental work.
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Affiliation(s)
- Felipe A. Torres
- Department of Electronic Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile
- Advanced Center for Electrical and Electronic Engineering (AC3E), Valparaíso, Chile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Advanced Center for Electrical and Electronic Engineering (AC3E), Valparaíso, Chile
| | - María-José Escobar
- Department of Electronic Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile
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26
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Harrington MO, Ashton JE, Ngo HVV, Cairney SA. Phase-locked auditory stimulation of theta oscillations during rapid eye movement sleep. Sleep 2021; 44:5960115. [PMID: 33159523 DOI: 10.1093/sleep/zsaa227] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/24/2020] [Indexed: 12/15/2022] Open
Abstract
Auditory closed-loop stimulation is a non-invasive technique that has been widely used to augment slow oscillations during non-rapid eye movement sleep. Based on the principles of closed-loop stimulation, we developed a novel protocol for manipulating theta activity (3-7 Hz) in rapid eye movement (REM) sleep. Sixteen healthy young adults were studied in two overnight conditions: Stimulation and Sham. In the Stimulation condition, 1 s of 5 Hz amplitude-modulated white noise was delivered upon detection of two supra-threshold theta cycles throughout REM sleep. In the Sham condition, corresponding time points were marked but no stimulation was delivered. Auditory stimulation entrained EEG activity to 5 Hz and evoked a brief (~0.5 s) increase in theta power. Interestingly, this initial theta surge was immediately followed by a prolonged (~3 s) period of theta suppression. Stimulation also induced a prolonged (~2 s) increase in beta power. Our results provide the first demonstration that the REM sleep theta rhythm can be manipulated in a targeted manner via auditory stimulation. Accordingly, auditory stimulation might offer a fruitful avenue for investigating REM sleep electrophysiology and its relationship to behavior.
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Affiliation(s)
| | | | - Hong-Viet V Ngo
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, The Netherlands.,Department of Psychology, University of Lübeck, Lübeck, Germany
| | - Scott A Cairney
- Department of Psychology, University of York, Heslington, York, UK.,York Biomedical Research Institute (YBRI), University of York, Heslington, York, UK
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27
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Cordone S, Scarpelli S, Alfonsi V, De Gennaro L, Gorgoni M. Sleep-Based Interventions in Alzheimer's Disease: Promising Approaches from Prevention to Treatment along the Disease Trajectory. Pharmaceuticals (Basel) 2021; 14:ph14040383. [PMID: 33921870 PMCID: PMC8073746 DOI: 10.3390/ph14040383] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/10/2021] [Accepted: 04/16/2021] [Indexed: 02/07/2023] Open
Abstract
The multifactorial nature of Alzheimer’s disease (AD) has led scientific researchers to focus on the modifiable and treatable risk factors of AD. Sleep fits into this context, given the bidirectional relationship with AD confirmed by several studies over the last years. Sleep disorders appear at an early stage of AD and continue throughout the entire course of the pathology. Specifically, sleep abnormalities, such as more fragmented sleep, increase in time of awakenings, worsening of sleep quality and primary sleep disorders raise with the severity and progression of AD. Intervening on sleep, therefore, means acting both with prevention strategies in the pre-clinical phase and with treatments during the course of the disease. This review explores sleep disturbances in the different stages of AD, starting from the pre-clinical stage. Particular attention is given to the empirical evidence investigating obstructive sleep apnea (OSA) disorder and the mechanisms overlapping and sharing with AD. Next, we discuss sleep-based intervention strategies in the healthy elderly population, mild cognitive impairment (MCI) and AD patients. We mention interventions related to behavioral strategies, combination therapies, and bright light therapy, leaving extensive space for new and raising evidence on continuous positive air pressure (CPAP) treatment effectiveness. Finally, we clarify the role of NREM sleep across the AD trajectory and consider the most recent studies based on the promising results of NREM sleep enhancement, which use innovative experimental designs and techniques.
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Affiliation(s)
- Susanna Cordone
- UniCamillus, Saint Camillus International University of Health Sciences, 00131 Rome, Italy;
| | - Serena Scarpelli
- Department of Psychology, University of Rome “Sapienza”, 00185 Rome, Italy; (S.S.); (M.G.)
| | | | - Luigi De Gennaro
- Department of Psychology, University of Rome “Sapienza”, 00185 Rome, Italy; (S.S.); (M.G.)
- IRCCS Fondazione Santa Lucia, 00179 Rome, Italy;
- Correspondence:
| | - Maurizio Gorgoni
- Department of Psychology, University of Rome “Sapienza”, 00185 Rome, Italy; (S.S.); (M.G.)
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28
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Schneider J, Lewis PA, Koester D, Born J, Ngo HVV. Susceptibility to auditory closed-loop stimulation of sleep slow oscillations changes with age. Sleep 2021; 43:5850478. [PMID: 32562487 PMCID: PMC7734479 DOI: 10.1093/sleep/zsaa111] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 05/10/2020] [Indexed: 11/20/2022] Open
Abstract
Study Objectives Cortical slow oscillations (SOs) and thalamocortical sleep spindles hallmark slow wave sleep and facilitate memory consolidation, both of which are reduced with age. Experiments utilizing auditory closed-loop stimulation to enhance these oscillations showed great potential in young and older subjects. However, the magnitude of responses has yet to be compared between these age groups. We examined the possibility of enhancing SOs and performance on different memory tasks in a healthy middle-aged population using this stimulation and contrast effects to younger adults. Methods In a within-subject design, 17 subjects (55.7 ± 1.0 years) received auditory stimulation in synchrony with SO up-states, which was compared to a no-stimulation sham condition. Overnight memory consolidation was assessed for declarative word-pairs and procedural finger-tapping skill. Post-sleep encoding capabilities were tested with a picture recognition task. Electrophysiological effects of stimulation were compared to a previous younger cohort (n = 11, 24.2 ± 0.9 years). Results Overnight retention and post-sleep encoding performance of the older cohort revealed no beneficial effect of stimulation, which contrasts with the enhancing effect the same stimulation protocol had in our younger cohort. Auditory stimulation prolonged endogenous SO trains and induced sleep spindles phase-locked to SO up-states in the older population. However, responses were markedly reduced compared to younger subjects. Additionally, the temporal dynamics of stimulation effects on SOs and spindles differed between age groups. Conclusions Our findings suggest that the susceptibility to auditory stimulation during sleep drastically changes with age and reveal the difficulties of translating a functional protocol from younger to older populations.
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Affiliation(s)
- Jules Schneider
- School of Biological Sciences, University of Manchester, Manchester, UK
- School of Psychology, Cardiff University, Cardiff, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Penelope A Lewis
- School of Biological Sciences, University of Manchester, Manchester, UK
- School of Psychology, Cardiff University, Cardiff, UK
- Corresponding authors. Hong-Viet V. Ngo, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Kapittelweg 29, 6525 EN Nijmegen, The Netherlands. ; Penelope A. Lewis, School of Psychology, Cardiff University, Cardiff, UK.
| | - Dominik Koester
- Institute for Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - Jan Born
- Institute for Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
- Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - Hong-Viet V Ngo
- Institute for Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
- Corresponding authors. Hong-Viet V. Ngo, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Kapittelweg 29, 6525 EN Nijmegen, The Netherlands. ; Penelope A. Lewis, School of Psychology, Cardiff University, Cardiff, UK.
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Fehér KD, Wunderlin M, Maier JG, Hertenstein E, Schneider CL, Mikutta C, Züst MA, Klöppel S, Nissen C. Shaping the slow waves of sleep: A systematic and integrative review of sleep slow wave modulation in humans using non-invasive brain stimulation. Sleep Med Rev 2021; 58:101438. [PMID: 33582581 DOI: 10.1016/j.smrv.2021.101438] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 10/14/2020] [Accepted: 11/10/2020] [Indexed: 01/19/2023]
Abstract
The experimental study of electroencephalographic slow wave sleep (SWS) stretches over more than half a century and has corroborated its importance for basic physiological processes, such as brain plasticity, metabolism and immune system functioning. Alterations of SWS in aging or pathological conditions suggest that modulating SWS might constitute a window for clinically relevant interventions. This work provides a systematic and integrative review of SWS modulation through non-invasive brain stimulation in humans. A literature search using PubMed, conducted in May 2020, identified 3220 studies, of which 82 fulfilled inclusion criteria. Three approaches have been adopted to modulate the macro- and microstructure of SWS, namely auditory, transcranial electrical and transcranial magnetic stimulation. Our current knowledge about the modulatory mechanisms, the space of stimulation parameters and the physiological and behavioral effects are reported and evaluated. The integration of findings suggests that sleep slow wave modulation bears the potential to promote our understanding of the functions of SWS and to develop new treatments for conditions of disrupted SWS.
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Affiliation(s)
- Kristoffer D Fehér
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Marina Wunderlin
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Jonathan G Maier
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Elisabeth Hertenstein
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Carlotta L Schneider
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Christian Mikutta
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland; Privatklinik Meiringen, Meiringen, Switzerland
| | - Marc A Züst
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Stefan Klöppel
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Christoph Nissen
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland.
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Schmid SR, Nissen C, Riemann D, Spiegelhalder K, Frase L. Auditorische Stimulation während des Schlafs. SOMNOLOGIE 2020. [DOI: 10.1007/s11818-020-00255-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ZusammenfassungDie Insomnie, d. h. eine Ein- und/oder Durchschlafstörung, die sich negativ auf die Leistungsfähigkeit und Tagesbefindlichkeit auswirkt, ist eine der häufigsten Erkrankungen in der Allgemeinbevölkerung. Sie wird derzeit meistens pharmakologisch und/oder psychotherapeutisch behandelt, wobei die pharmakologische Behandlung mit Benzodiazepin-Rezeptor-Agonisten zu Abhängigkeit führen kann und die Verfügbarkeit von für die Insomnie-Therapie ausgebildeten Psychotherapeuten momentan nicht in ausreichendem Maße gegeben ist. Durch innovative Behandlungsmethoden könnte hier eine Versorgungslücke effektiv geschlossen werden. Hierzu zählt die auditorische Stimulation, welche vorhandene Sinneskanäle nutzt, um den Schlaf zu beeinflussen. Bisher wurde die auditorische Stimulation vor allem zur Untersuchung von Prozessen der Gedächtniskonsolidierung bei gesunden Probanden angewendet, wobei erfolgreich eine Erhöhung langsamer Oszillationen erreicht wurde, welche vor allem während des Tiefschlafs auftreten. Erste Befunde und sekundäre Outcome-Parameter liefern Hinweise, dass die Potenzierung langsamer Oszillationen durch auditorische Stimulation den Schlaf vertiefen kann, jedoch wurde hierzu bislang keine Studie mit Insomniepatienten durchgeführt. Weitere Forschung bezüglich des Einflusses der Potenzierung langsamer Oszillationen auf die Linderung von Ein- und Durchschlafproblemen bei vorliegender nichtorganischer Insomnie erscheint daher geboten zu sein, um der hohen Beschwerdelast dieser Patientengruppe entgegenzuwirken.
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Jacob NK, Kings HO, Casson AJ. A smartphone based platform for portable non-invasive light and sound neuromodulation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:5228-5231. [PMID: 33019163 DOI: 10.1109/embc44109.2020.9175585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This paper presents a smartphone based system for presenting light and sound stimulation to a user for neuromodulation experiments. A smartphone platform was used to increase ease of use and enable out-of-the-clinic experiments. The created Android app provides both visual and auditory entrainment stimuli, along with a real-time extraction of ongoing electroencephalogram (EEG) phase using a Phase Locked Loop (PLL) for enabling closed loop simulations. Both visual and auditory stimulation is provided accurately in the 1-20 Hz range using the smartphone class hardware. Test results for both gave R squared fit values of 1 between a fitted line and the measured stimulation frequencies. Data from 13 subjects showed the PLL could track EEG phase in the slow oscillation band with an error of 14.83±38.47°, with an average of 0.04±0.20 ms processing overhead per sample.
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Salfi F, D'Atri A, Tempesta D, De Gennaro L, Ferrara M. Boosting Slow Oscillations during Sleep to Improve Memory Function in Elderly People: A Review of the Literature. Brain Sci 2020; 10:E300. [PMID: 32429181 PMCID: PMC7287854 DOI: 10.3390/brainsci10050300] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 02/05/2023] Open
Abstract
Sleep represents a crucial time window for the consolidation of memory traces. In this view, some brain rhythms play a pivotal role, first of all the sleep slow waves. In particular, the neocortical slow oscillations (SOs), in coordination with the hippocampal ripples and the thalamocortical spindles, support the long-term storage of the declarative memories. The aging brain is characterized by a disruption of this complex system with outcomes on the related cognitive functions. In recent years, the advancement of the comprehension of the sleep-dependent memory consolidation mechanisms has encouraged the development of techniques of SO enhancement during sleep to induce cognitive benefits. In this review, we focused on the studies reporting on the application of acoustic or electric stimulation procedures in order to improve sleep-dependent memory consolidation in older subjects. Although the current literature is limited and presents inconsistencies, there is promising evidence supporting the perspective to non-invasively manipulate the sleeping brain electrophysiology to improve cognition in the elderly, also shedding light on the mechanisms underlying the sleep-memory relations during healthy and pathological aging.
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Affiliation(s)
- Federico Salfi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Aurora D'Atri
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
| | - Daniela Tempesta
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Luigi De Gennaro
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
| | - Michele Ferrara
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
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Abstract
Sleep duration and lifespan vary greatly across Animalia. Human studies have demonstrated that ageing reduces the ability to obtain deep restorative sleep, and this may play a causative role in the development of age-related neurodegenerative disorders. Animal models are widely used in sleep and ageing studies. Importantly, in contrast to human studies, evidence from laboratory rodents suggests that sleep duration is increased with ageing, while evidence for reduced sleep intensity and consolidation is inconsistent. Here we discuss two possible explanations for these species differences. First, methodological differences between studies in humans and laboratory rodents may prevent straightforward comparison. Second, the role of ecological factors, which have a profound influence on both ageing and sleep, must be taken into account. We propose that the dynamics of sleep across the lifespan reflect both age-dependent changes in the neurobiological substrates of sleep as well as the capacity to adapt to the environment.
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