scholarly journals Visual imagery and visual perception induce similar changes in occipital slow waves of sleep

2019 ◽  
Author(s):  
Giulio Bernardi ◽  
Monica Betta ◽  
Jacinthe Cataldi ◽  
Andrea Leo ◽  
José Haba-Rubio ◽  
...  
Keyword(s):  
Slow Wave ◽  
Visual Imagery ◽  
Visual Stimulation ◽  
Nrem Sleep ◽  
Occipital Cortex ◽  
Slow Waves ◽  
Visual Areas ◽  
Eeg Changes ◽  
High Degree ◽  
Cortical Visual Areas

AbstractPrevious studies have shown that regional slow wave activity (SWA) during NREM-sleep is modulated by prior experience and learning. While this effect has been convincingly demonstrated for the sensorimotor domain, attempts to extend these findings to the visual system have provided mixed results. Here we asked whether depriving subjects of external visual stimuli during daytime would lead to regional changes in slow waves during sleep and whether the degree of ‘internal visual stimulation’ (spontaneous imagery) would influence such changes. In two 8h-long sessions spaced one-week apart, twelve healthy volunteers either were blindfolded while listening to audiobooks or watched movies (control condition), after which their sleep was recorded with high-density EEG. We found that during NREM-sleep the number of small, local slow waves in the occipital cortex decreased after listening with blindfolding relative to movie watching in a way that depended on the degree of visual imagery subjects reported during blindfolding: subjects with low visual imagery showed a significant reduction of occipital sleep slow waves, while those who reported a high degree of visual imagery did not. We also found a positive relationship between the reliance on visual imagery during blindfolding and audiobook listening and the degree of correlation in sleep SWA between visual areas and language-related areas. These preliminary results demonstrate that short-term alterations in visual experience may trigger slow wave changes in cortical visual areas. Furthermore, they suggest that plasticity-related EEG changes during sleep may reflect externally induced (‘bottom-up’) visual experiences, as well as internally generated (‘top-down’) processes.

scholarly journals Visual imagery and visual perception induce similar changes in occipital slow waves of sleep

2019 ◽  
Vol 121 (6) ◽  
pp. 2140-2152 ◽  
Author(s):  
Giulio Bernardi ◽  
Monica Betta ◽  
Jacinthe Cataldi ◽  
Andrea Leo ◽  
José Haba-Rubio ◽  
...  
Keyword(s):  
Visual Perception ◽  
Eye Movement ◽  
Slow Wave ◽  
Visual Imagery ◽  
Nrem Sleep ◽  
Wave Activity ◽  
Slow Waves ◽  
Slow Wave Activity ◽  
Short Term ◽  
Visual Areas

Previous studies have shown that regional slow-wave activity (SWA) during non-rapid eye movement (NREM) sleep is modulated by prior experience and learning. Although this effect has been convincingly demonstrated for the sensorimotor domain, attempts to extend these findings to the visual system have provided mixed results. In this study we asked whether depriving subjects of external visual stimuli during daytime would lead to regional changes in slow waves during sleep and whether the degree of “internal visual stimulation” (spontaneous imagery) would influence such changes. In two 8-h sessions spaced 1 wk apart, 12 healthy volunteers either were blindfolded while listening to audiobooks or watched movies (control condition), after which their sleep was recorded with high-density EEG. We found that during NREM sleep, the number of small, local slow waves in the occipital cortex decreased after listening with blindfolding relative to movie watching in a way that depended on the degree of visual imagery subjects reported during blindfolding: subjects with low visual imagery showed a significant reduction of occipital sleep slow waves, whereas those who reported a high degree of visual imagery did not. We also found a positive relationship between the reliance on visual imagery during blindfolding and audiobook listening and the degree of correlation in sleep SWA between visual areas and language-related areas. These preliminary results demonstrate that short-term alterations in visual experience may trigger slow-wave changes in cortical visual areas. Furthermore, they suggest that plasticity-related EEG changes during sleep may reflect externally induced (“bottom up”) visual experiences, as well as internally generated (“top down”) processes.NEW & NOTEWORTHY Previous work has shown that slow-wave activity, a marker of sleep depth, is linked to neural plasticity in the sensorimotor cortex. We show that after short-term visual deprivation, subjects who reported little visual imagery had a reduced incidence of occipital slow waves. This effect was absent in subjects who reported strong spontaneous visual imagery. These findings suggest that visual imagery may “substitute” for visual perception and induce similar changes in non-rapid eye movement slow waves.

scholarly journals Bidirectional Interaction of Hippocampal Ripples and Cortical Slow Waves Leads to Coordinated Spiking Activity During NREM Sleep

2020 ◽  
Vol 31 (1) ◽  
pp. 324-340
Author(s):  
Pavel Sanda ◽  
Paola Malerba ◽  
Xi Jiang ◽  
Giri P Krishnan ◽  
Jorge Gonzalez-Martinez ◽  
...  
Keyword(s):  
Slow Wave ◽  
Memory Consolidation ◽  
Slow Wave Sleep ◽  
Nrem Sleep ◽  
Slow Waves ◽  
Slow Oscillation ◽  
Cortical Input ◽  
Sharp Wave ◽  
Up States ◽  
Intracranial Recordings

Abstract The dialogue between cortex and hippocampus is known to be crucial for sleep-dependent memory consolidation. During slow wave sleep, memory replay depends on slow oscillation (SO) and spindles in the (neo)cortex and sharp wave-ripples (SWRs) in the hippocampus. The mechanisms underlying interaction of these rhythms are poorly understood. We examined the interaction between cortical SO and hippocampal SWRs in a model of the hippocampo–cortico–thalamic network and compared the results with human intracranial recordings during sleep. We observed that ripple occurrence peaked following the onset of an Up-state of SO and that cortical input to hippocampus was crucial to maintain this relationship. A small fraction of ripples occurred during the Down-state and controlled initiation of the next Up-state. We observed that the effect of ripple depends on its precise timing, which supports the idea that ripples occurring at different phases of SO might serve different functions, particularly in the context of encoding the new and reactivation of the old memories during memory consolidation. The study revealed complex bidirectional interaction of SWRs and SO in which early hippocampal ripples influence transitions to Up-state, while cortical Up-states control occurrence of the later ripples, which in turn influence transition to Down-state.

scholarly journals 1133 The Recovery of Sleep Oscillations in Acute to Chronic Traumatic Brain Injury

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A431-A431
Author(s):  
E Sanchez ◽  
C Duclos ◽  
S Van Der Maren ◽  
H El-Khatib ◽  
C Arbour ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Slow Wave ◽  
Nrem Sleep ◽  
Slow Waves ◽  
Hospital Environment ◽  
Chronic Stage ◽  
Orthopedic Injuries ◽  
The Brain ◽  
Sleep Cycles

Abstract Introduction Slow waves and spindles are essential oscillations occurring during NREM sleep that may be disrupted by moderate to severe traumatic brain injury (TBI). We investigated these oscillations in the acute and chronic trauma stage. Methods Four groups were tested with whole-night polysomnography: hospitalized patients with acute TBI (n=10, 29.7±13.8y) or severe orthopedic injuries (n=15, 39.9±17.1y), chronic TBI including 9 returning from the acute TBI group (n=43, 31.9±13.5y), and healthy controls (n=36, 30.5±12.7y). Characteristics for slow waves (density, amplitude, slope, frequency, duration) and spindles (density, amplitude, frequency, duration) were quantified over N2 and N3 sleep for the first three sleep cycles, and groups were compared using one-way ANOVAs. Results One-way ANOVAs showed group effects only for slow wave density (F=4.11 to 6.04, p=0.009 to 0.0008)) and spindle density (F=3.3 to 8.8, p=0.02 to 0.00003). These effects were present for the 2nd and 3rd sleep cycles, but not the 1st. More specifically, slow wave density in acute TBI was higher than in controls, and returned to normal levels in the chronic stage. Conversely, spindle density in acute TBI was lower than in controls and returned to normal levels in the chronic stage. No group difference was observed for the orthopedic group. Conclusion Our results suggest that immediately after a severely disruptive event such as a TBI, the brain needs additional deeper sleep to recover, resulting in more slow waves but also in less spindles. These changes are only present in the 2nd and 3rd sleep cycles, reflecting an absence of the expected dissipation of slow waves, which may suggest increased homeostatic sleep pressure due to the brain injury. Limits to interpretation include the hospital environment and medication, but the absence of changes in the orthopedic group under similar conditions emphasizes the effect of the brain injury itself. Support Canadian Institutes of Health Research (CIHR) and Fonds de Recherche Québec-Santé (FRQS)

Cortical visual areas process intestinal information during slow-wave sleep

2012 ◽  
Vol 25 (3) ◽  
pp. 268-e169 ◽  
Author(s):  
I. N. Pigarev ◽  
V. A. Bagaev ◽  
E. V. Levichkina ◽  
G. O. Fedorov ◽  
I. I. Busigina
Keyword(s):  
Slow Wave ◽  
Slow Wave Sleep ◽  
Visual Areas ◽  
Cortical Visual Areas

scholarly journals Schizophrenia-associated variation at ZNF804A correlates with altered experience-dependent dynamics of sleep slow-waves and spindles in healthy young adults

2020 ◽  
Author(s):  
Ullrich Bartsch ◽  
Laura J Corbin ◽  
Charlotte Hellmich ◽  
Michelle Taylor ◽  
Kayleigh E Easey ◽  
...  
Keyword(s):  
Slow Wave ◽  
Memory Consolidation ◽  
Neural Circuit ◽  
Activity Patterns ◽  
Nrem Sleep ◽  
Slow Waves ◽  
Network Activity ◽  
Healthy Population ◽  
Adult Males ◽  
Performance Improvements

ABSTRACTBackgroundThe rs1344706 polymorphism in ZNF804A is robustly associated with schizophrenia (SZ), yet brain and behavioral phenotypes related to this variant have not been extensively characterized. In turn, SZ is associated with abnormal non-rapid eye movement (NREM) sleep neurophysiology. To examine whether rs1344706 is associated with intermediate neurophysiological traits in the absence of disease, we assessed the relationship between genotype, sleep neurophysiology, and sleep-dependent memory consolidation in healthy participants.MethodsWe recruited healthy adult males, with no history of psychiatric disorder, from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Participants were homozygous for either the SZ-associated ‘A’ allele (N=25) or the alternative ‘C’ allele (N=22) at rs1344706. Actigraphy, polysomnography (PSG) and a motor sequencing task (MST) were used to characterize daily activity patterns, sleep neurophysiology and sleep-dependent memory consolidation.ResultsAverage MST learning and sleep-dependent performance improvements were similar across genotype groups, but with increased variability in the AA group. CC participants showed increased slow-wave and spindle amplitudes, plus augmented coupling of slow-wave activity across recording electrodes after learning. Slow-waves and spindles in those with the AA genotype were insensitive to learning, whilst slow-wave coherence decreased following MST training.ConclusionWe describe evidence that rs1344706 polymorphism in ZNF804A is associated with changes in experience- and sleep-dependent, local and distributed neural network activity that supports offline information processing during sleep in a healthy population. These findings highlight the utility of sleep neurophysiology in mapping the impacts of SZ-associated variants on neural circuit oscillations and function.

scholarly journals Integrity of corpus callosum is essential for the cross-hemispheric propagation of sleep slow waves: a high-density EEG study in split-brain patients

2019 ◽  
Author(s):  
Giulia Avvenuti ◽  
Giacomo Handjaras ◽  
Monica Betta ◽  
Jacinthe Cataldi ◽  
Laura Sophie Imperatori ◽  
...  
Keyword(s):  
Wave Propagation ◽  
White Matter ◽  
Corpus Callosum ◽  
Slow Wave ◽  
Nrem Sleep ◽  
High Density ◽  
Slow Waves ◽  
Wave Parameter ◽  
P Value ◽  
The Cross

AbstractThe slow waves of NREM-sleep (0.5-4Hz) reflect experience-dependent plasticity and play a direct role in the restorative functions of sleep. Importantly, slow waves behave as traveling waves and their propagation is assumed to reflect the structural properties of white matter connections. Based on this assumption, the corpus callosum (CC) may represent the main responsible for cross-hemispheric slow wave propagation. To verify this hypothesis, here we studied a group of patients who underwent total callosotomy due to drug-resistant epilepsy. Overnight high-density (hd)-EEG recordings (256 electrodes) were performed in five totally callosotomized in-patients (CP; 40-53y, 2F), in three control non-callosotomized neurological in-patients (NP; 44-66y, 2F, 1M epileptic), and in an additional sample of 24 healthy adult subjects (HS; 20-47y, 13F). Data were inspected to select NREM-sleep epochs and artefactual or non-physiological activity was rejected. Slow waves were detected using an automated algorithm and their properties and propagation patterns were computed. For each slow wave parameter and for each patient, the relative z-score and the corresponding p-value were calculated with respect to the distribution represented by the HS-group. Group differences were considered significant only when a Bonferroni corrected P < 0.05 was observed in all the CP and in none of the NP. A regression-based adjustment was used to exclude potential confounding effects of age. Slow wave density, amplitude, slope and propagation speed did not differ across CP and HS. In all CP slow waves displayed a significantly reduced probability of cross-hemispheric propagation and a stronger inter-hemispheric asymmetry. Moreover, we found that the incidence of large slow waves tended to differ across hemispheres within individual NREM epochs, with a relative predominance of the right over the left hemisphere in both CP and HS. The absolute magnitude of this inter-hemispheric difference was significantly greater in CP relative to HS. This effect did not depend on differences in slow wave origin within each hemisphere across groups. Present results indicate that the integrity of the CC is essential for the cross-hemispheric traveling of sleep slow waves, supporting the assumption of a direct relationship between white matter structural integrity and cross-hemispheric slow wave propagation. Our findings also imply a prominent role of cortico-cortical connections, rather than cortico-subcortico-cortical loops, in slow wave cross-hemispheric synchronization. Finally, this data indicate that the lack of the CC does not lead to differences in sleep depth, in terms of slow wave generation/origin, across brain hemispheres.

scholarly journals Individual slow wave morphology is a marker of ageing

2018 ◽  
Author(s):  
Péter P Ujma ◽  
Péter Simor ◽  
Axel Steiger ◽  
Martin Dresler ◽  
Róbert Bódizs
Keyword(s):  
Slow Wave ◽  
Penalized Regression ◽  
Nrem Sleep ◽  
Neuronal Firing ◽  
Slow Waves ◽  
Detection Methods ◽  
State Transitions ◽  
Age Related ◽  
Wave Morphology ◽  
The Individual

AbstractSlow wave activity is a hallmark of deep NREM sleep. Scalp slow wave morphology is stereotypical, it is highly correlated with the synchronized onset and cessation of cortical neuronal firing measured from the surface or depth of the cortex, strongly affected by ageing, and these changes are causally associated with age-related cognitive decline. We investigated how normal ageing affects the individual morphology of the slow wave, and whether these changes are captured by the summary slow wave parameters generally used in the literature. We recorded full-night polysomnography in 159 subjects (age 17-69 years) and automatically detected slow waves using six different detection methods to ensure methodological robustness. We established individual slow morphologies at 501 data points for each subject and also calculated the individual average slow wave amplitude, average ascending and descending slope steepness and the total number of slow waves (gross parameters). Using LASSO penalized regression we found that fine-grained slow wave morphology is associated with age beyond gross parameters, with young subjects having faster slow wave polarity reversals, suggesting a more efficient initiation and termination of slow wave down- and upstates. Our results demonstrate the superiority of the high-resolution slow wave morphology as a biomarker of ageing, and highlights state transitions as promising targets of restorative stimulation-based interventions.

scholarly journals NREM sleep signatures of memory disruption and psychiatric symptoms in young people with 22q11.2 deletion syndrome

2021 ◽  
Author(s):  
Nicholas A Donnelly ◽  
Ullrich Bartsch ◽  
Hayley Moulding ◽  
Christopher Eaton ◽  
Hugh Marston ◽  
...  
Keyword(s):  
Young People ◽  
Slow Wave ◽  
Psychiatric Symptoms ◽  
22Q11.2 Deletion Syndrome ◽  
Nrem Sleep ◽  
Slow Waves ◽  
Sleep Architecture ◽  
Deletion Syndrome ◽  
Adhd Symptoms ◽  
22Q11.2 Deletion

Background Young people with 22q11.2 Deletion Syndrome (22q11.2DS) are at increased risk of schizophrenia, intellectual disability, Attention-Deficit Hyperactivity Disorder (ADHD) and autism spectrum disorder. In common with these conditions, 22q11.2DS is also associated with sleep problems. We investigated whether abnormal sleep or sleep-dependent network activity in 22q11.2DS may reflect convergent, early signatures of neural circuit disruption also evident in associated neurodevelopmental conditions. Methods We recorded high-density sleep EEG in young people (6-20 years) with 22q11.2DS (n=28) and their unaffected siblings (n=17), quantifying the associations between sleep architecture, EEG oscillations (spindles and slow-waves) and psychiatric symptoms. We also measured performance on a memory task before and after sleep. Results 22q11.2DS was associated with significant alterations in sleep architecture, including a greater proportion of N3 sleep and lower proportions of N1 and REM sleep than in siblings. During NREM sleep, deletion carriers showed increased power in slow delta and sigma oscillations, increased slow-wave and spindle amplitudes, and altered coupling between spindles and slow-waves. Spindle and slow-wave amplitudes correlated positively with overnight memory in controls, but negatively in 22q11.2DS. Mediation analyses indicated that increased slow-wave amplitude in 22q11.2DS was statistically mediated via ADHD symptoms. Conclusions This first study of sleep EEG in 22q11.2DS highlights several alterations in EEG signatures of NREM sleep, some of which were associated with ADHD symptoms. ADHD symptoms have previously been associated with incident psychotic symptoms in 22q11.2DS; our findings may therefore reflect delayed or compromised neurodevelopmental processes which precede, and may be biomarkers for, psychotic disorders.

scholarly journals Characterization of overnight slow-wave slope changes across development in an age-, amplitude-, and region-dependent manner

SLEEP ◽  
2020 ◽  
Vol 43 (9) ◽  
Author(s):  
Valeria Jaramillo ◽  
Carina Volk ◽  
Angelina Maric ◽  
Melanie Furrer ◽  
Sara Fattinger ◽  
...  
Keyword(s):  
Slow Wave ◽  
Regional Differences ◽  
Central Area ◽  
Nrem Sleep ◽  
Synaptic Strength ◽  
Slow Waves ◽  
Brain Maturation ◽  
Dependent Manner ◽  
Slope Change ◽  
Wave Slope

Abstract Study Objectives The restorative function of sleep has been linked to a net reduction in synaptic strength. The slope of slow-waves, a major characteristic of non-rapid eye movement (NREM) sleep, has been shown to directly reflect synaptic strength, when accounting for amplitude changes across the night. In this study, we aimed to investigate overnight slope changes in the course of development in an age-, amplitude-, and region-dependent manner. Methods All-night high-density electroencephalography data were analyzed in a cross-sectional population of 60 healthy participants in the age range of 8–29 years. To control for amplitude changes across the night, we matched slow-waves from the first and the last hour of NREM sleep according to their amplitude. Results We found a reduction of slow-wave slopes from the first to the last hour of NREM sleep across all investigated ages, amplitudes, and most brain regions. The overnight slope change was largest in children and decreased toward early adulthood. A topographical analysis revealed regional differences in slope change. Specifically, for small amplitude waves the decrease was smallest in an occipital area, whereas for large amplitude waves, the decrease was smallest in a central area. Conclusions The larger slope decrease in children might be indicative of a boosted renormalization of synapses during sleep in childhood, which, in turn, might be related to increased plasticity during brain maturation. Regional differences in the extent of slow-wave slope reduction may reflect a “smart” down-selection process or, alternatively, indicate amplitude-dependent differences in the generation of slow-waves.

scholarly journals 0352 A Large-Scale EEG Study at Home to Objectivise Effects of Ageing on Slow Wave Sleep and Process S

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A133-A134
Author(s):  
K El Kanbi ◽  
V Thorey ◽  
L Artemis ◽  
A Chouraki ◽  
T Trichet ◽  
...  
Keyword(s):  
Slow Wave ◽  
Large Scale ◽  
Slow Wave Sleep ◽  
Large Population ◽  
Nrem Sleep ◽  
Slow Waves ◽  
High Signal ◽  
Eeg Signals ◽  
Sleep Complaints ◽  
Loop Procedure

Abstract Introduction Several studies have shown slow wave sleep (SWS) is altered with ageing. However, most of these studies have been conducted in-lab and usually over a single night. In this study, we assessed the evolution of process S with ageing by analysing the dynamics of endogenous and auditory-evoked slow waves in a large population. Methods 300 participants (200 M, 20 - 70 y.o.) were selected from volunteers users wearing a sleep headband for at least 3 nights, meeting the criteria of high signal quality and having no subjective sleep complaints nor being shift-workers. The Dreem headband is a connected device able to monitor EEG signals as well as pulse and movement and performs sleep staging in real-time automatically. Slow waves were detected as large negative deflections on the filtered EEG signals during NREM sleep. The auditory evoked slow waves were done using a previously validated closed-loop procedure. Results In our study, age was strongly correlated with N3 sleep duration (r=-0.34, p&lt;0.0001), slow wave amplitude (r=-0.25, p&lt;0.0001), and slow wave density (r=-0.40, p&lt;0.0001). The slope of the slow wave activity, representing the process S here, was significantly decreased (r=-0.32, p&lt;0.0001). This effect was mainly due to changes in the density of slow waves in the first 2 hours of sleep (r=-0.41, p&lt;0.0001). Finally, our results show a decrease in the probability of auditory evoked slow waves (r=-0.43, p&lt;0.0001). Conclusion These results confirmed the in-lab studies showing a heterogeneous alteration of homoeostatic process S with age, as well as a general decrease of slow wave occurrences, that is observed in parallel of a decrease of the probability of evoking slow waves, suggesting a global change in the system responsible for slow wave generation. Support This study was supported by Dreem sas and ANR, FLAG ERA 2015, HPB SLOW-Dyn

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