scholarly journals Time Course of Sleep Inertia Dissipation in Memory Tasks

2021 ◽  
Vol 11 (8) ◽  
pp. 3354
Author(s):  
Miranda Occhionero ◽  
Marco Fabbri ◽  
Lorenzo Tonetti ◽  
Monica Martoni ◽  
Vincenzo Natale
Keyword(s):  
Time Course ◽  
Time Window ◽  
Sleep Stage ◽  
Memory Task ◽  
Procedural Memory ◽  
Sleep Inertia ◽  
Procedural Task ◽  
Subjective Alertness ◽  
Nighttime Sleep ◽  
Si Effect

Sleep inertia (SI) refers to a complex psychophysiological phenomenon, observed after awakening, that can be described as the gradual recovery of waking-like status. The time course of cognitive performance dissipation in an everyday life condition is still unclear, especially in terms of the sleep stage at awakening (REM or NREM-stage 2) and the relative effects on performance. The present study aimed to investigate the SI dissipation in different memory performances upon spontaneous morning awakening after uninterrupted nighttime sleep. Eighteen young adults (7 females; mean age 24.9 ± 3.14 years) spent seven non-consecutive nights (one baseline, three REM awakenings and three St2 awakenings) in the laboratory under standard polysomnographic (PSG) control. Participants were tested after three REM awakenings and three St2 awakenings, and three times at 11:00 a.m. as a control condition. In each testing session, participants filled in the Global Vigor and Affect Scale and carried out one memory task (episodic, semantic, or procedural task). For each condition, participants were tested every 10 min within a time window of 80 min. In accordance with previous studies, SI affected subjective alertness throughout the entire time window assessed. Moreover, SI significantly affected performance speed but not accuracy in the semantic task. With reference to this task, the SI effect dissipated within 30 min of awakening from REM, and within 20 min of awakening from St2. No significant SI effect was observed on episodic or procedural memory tasks.

A refined model of sleep and the time course of memory formation

2005 ◽  
Vol 28 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Matthew P. Walker
Keyword(s):  
Time Course ◽  
Sleep Stage ◽  
Procedural Memory ◽  
Memory Formation ◽  
Procedural Learning ◽  
Initial Acquisition ◽  
Stabilization Phase ◽  
Time Awake ◽  
Dependent Learning ◽  
Enhanced Learning

Research in the neurosciences continues to provide evidence that sleep plays a role in the processes of learning and memory. There is less of a consensus, however, regarding the precise stages of memory development during which sleep is considered a requirement, simply favorable, or not important. This article begins with an overview of recent studies regarding sleep and learning, predominantly in the procedural memory domain, and is measured against our current understanding of the mechanisms that govern memory formation. Based on these considerations, I offer a new neurocognitive framework of procedural learning, consisting first of acquisition, followed by two specific stages of consolidation, one involving a process of stabilization, the other involving enhancement, whereby delayed learning occurs. Psychophysiological evidence indicates that initial acquisition does not rely fundamentally on sleep. This also appears to be true for the stabilization phase of consolidation, with durable representations, resistant to interference, clearly developing in a successful manner during time awake (or just time, per se). In contrast, the consolidation stage, resulting in additional/enhanced learning in the absence of further rehearsal, does appear to rely on the process of sleep, with evidence for specific sleep-stage dependencies across the procedural domain. Evaluations at a molecular, cellular, and systems level currently offer several sleep specific candidates that could play a role in sleep-dependent learning. These include the upregulation of select plasticity-associated genes, increased protein synthesis, changes in neurotransmitter concentration, and specific electrical events in neuronal networks that modulate synaptic potentiation.

scholarly journals Spatial asymmetries (“pseudoneglect”) in free visual exploration—modulation of age and relationship to line bisection

2021 ◽  
Author(s):  
Kathrin Chiffi ◽  
Lorenzo Diana ◽  
Matthias Hartmann ◽  
Dario Cazzoli ◽  
Claudio L. Bassetti ◽  
...  
Keyword(s):  
Time Course ◽  
Time Window ◽  
Tracking System ◽  
Line Bisection ◽  
Visual Exploration ◽  
Bisection Task ◽  
Subjective Alertness ◽  
Line Bisection Task ◽  
Gaze Position ◽  
Exploration Task

AbstractWhen humans visually explore an image, they typically tend to start exploring its left side. This phenomenon, so-called pseudoneglect, is well known, but its time-course has only sparsely been studied. Furthermore, it is unclear whether age influences pseudoneglect, and the relationship between visuo-spatial attentional asymmetries in a free visual exploration task and a classical line bisection task has not been established. To address these questions, 60 healthy participants, aged between 22 and 86, were assessed by means of a free visual exploration task with a series of naturalistic, colour photographs of everyday scenes, while their gaze was recorded by means of a contact-free eye-tracking system. Furthermore, a classical line bisection task was administered, and information concerning handedness and subjective alertness during the experiment was obtained. The results revealed a time-sensitive window during visual exploration, between 260 and 960 ms, in which age was a significant predictor of the leftward bias in gaze position, i.e., of pseudoneglect. Moreover, pseudoneglect as assessed by the line bisection task correlated with the average gaze position throughout a time-window of 300–1490 ms during the visual exploration task. These results suggest that age influences visual exploration and pseudoneglect in a time-sensitive fashion, and that the degree of pseudoneglect in the line bisection task correlates with the average gaze position during visual exploration in a time-sensitive manner.

Converging Evidence That Neural Plasticity Underlies Transcranial Direct-Current Stimulation

2021 ◽  
Vol 33 (1) ◽  
pp. 146-157
Author(s):  
Chong Zhao ◽  
Geoffrey F. Woodman
Keyword(s):  
Visual Search ◽  
Direct Current ◽  
Neural Plasticity ◽  
Transcranial Direct Current Stimulation ◽  
Time Course ◽  
Memory Task ◽  
Long Term Memory ◽  
Visual Stream ◽  
Direct Current Stimulation ◽  
The Brain

It is not definitely known how direct-current stimulation causes its long-lasting effects. Here, we tested the hypothesis that the long time course of transcranial direct-current stimulation (tDCS) is because of the electrical field increasing the plasticity of the brain tissue. If this is the case, then we should see tDCS effects when humans need to encode information into long-term memory, but not at other times. We tested this hypothesis by delivering tDCS to the ventral visual stream of human participants during different tasks (i.e., recognition memory vs. visual search) and at different times during a memory task. We found that tDCS improved memory encoding, and the neural correlates thereof, but not retrieval. We also found that tDCS did not change the efficiency of information processing during visual search for a certain target object, a task that does not require the formation of new connections in the brain but instead relies on attention and object recognition mechanisms. Thus, our findings support the hypothesis that direct-current stimulation modulates brain activity by changing the underlying plasticity of the tissue.

Reduced information processing speed as primum movens for cognitive decline in MS

2014 ◽  
Vol 21 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Jeroen Van Schependom ◽  
Marie B D’hooghe ◽  
Krista Cleynhens ◽  
Mieke D’hooge ◽  
Marie-Claire Haelewyck ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Information Processing ◽  
Processing Speed ◽  
Time Course ◽  
Age At Onset ◽  
Memory Task ◽  
Cognitive Domain ◽  
Information Processing Speed ◽  
Survival Curves ◽  
Cross Sectional

Background: Cognitive impairment affects half of the multiple sclerosis (MS) patient population and is an important contributor to patients’ daily activities. Most cognitive impairment studies in MS are, however, cross-sectional or/and focused on the early disease stages. Objective: We aim to assess the time course of decline of different cognitive domains. Methods: We collected neuropsychological data on 514 MS patients to construct Kaplan-Meier survival curves of the tests included in the Neuropsychological Screening Battery for MS (NSBMS) and the Symbol Digit Modalities Test (SDMT). Cox-proportional hazard models were constructed to examine the influence of MS onset type, age at onset, gender, depression and level of education on the time course, expressed as age or disease. Results: Survival curves of tests focusing on information processing speed (IPS) declined significantly faster than tests with less specific demands of IPS. Median age for pathological decline was 56.2 years (95% CI: 54.4–58.2) on the SDMT and 63.9 years (95% CI: 60–66.9) on the CLTR, a memory task. Conclusion: In conclusion, IPS is the cognitive domain not only most widely affected by MS but it is also the first cognitive deficit to emerge in MS.

scholarly journals REM sleep behavior disorder in children with type 1 Narcolepsy treated with Sodium Oxybate

Neurology ◽  
2020 ◽  
pp. 10.1212/WNL.0000000000011157
Author(s):  
Elena Antelmi ◽  
Marco Filardi ◽  
Fabio Pizza ◽  
Stefano Vandi ◽  
Monica Moresco ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Sleep Stage ◽  
Rem Sleep Behavior Disorder ◽  
Behavior Disorder ◽  
Sodium Oxybate ◽  
Direct Role ◽  
Sleep Behavior ◽  
Rem Sleep Without Atonia ◽  
Nighttime Sleep

Objective:The aim was to study the effect of stable treatment with Sodium Oxybate (SO) on nocturnal REM sleep behavior disorder (RBD) and REM sleep without atonia (RSWA) that severely affected children with type 1 narcolepsy (NT1.Methods:Nineteen NT1 children and adolescents (nine females; mean age 12.5±2.7, mean disease duration: 3.4±1.6 years) underwent neurological investigations and video-polysomnography (v-PSG) at baseline and after three months of stable treatment with SO.v-PSG was independently analysed by two sleep experts, in order to rate RBD episodes. RSWA was automatically computed by means of the validated REM sleep atonia index (RAI).Results:Compared to baseline, RAI significantly improved (p< 0.05) and complex movements during REM sleep were remarkably reduced after stable treatment with SO. Compared to baseline, children also reported improvement in clinical complaints and showed a different nighttime sleep stage architecture.Conclusions:RBD and RSWA improved after treatment with SO, pointing to a direct role of the drug in modulating motor control during REM sleep.

Dynamic Recording of Cell Death in the In Vitro Dorsal Vagal Nucleus of Rats in Response to Metabolic Arrest

2003 ◽  
Vol 89 (1) ◽  
pp. 551-561 ◽  
Author(s):  
Michael Müller ◽  
Klaus Ballanyi
Keyword(s):  
Cell Death ◽  
Propidium Iodide ◽  
Neuronal Death ◽  
Time Course ◽  
Time Window ◽  
Membrane Integrity ◽  
Brain Slices ◽  
Limited Information ◽  
Histological Techniques ◽  
Metabolic Arrest

Anoxic/ischemic neuronal death is usually assessed in cell cultures or in vivo within a time window of 24 h to several days using the nucleic acid stain propidium iodide or histological techniques. Accordingly, there is limited information on the time course of such neuronal death. We loaded acute rat brain stem slices with propidium iodide for dynamic fluorometric recording of metabolic arrest-related cell death in the dorsal vagal nucleus. This model was chosen because dorsal vagal neurons show a graded response to metabolic inhibition: anoxia and aglycemia cause a sustained hyperpolarization, whereas ischemia induces a glutamate-mediated, irreversible depolarization. We found that the number of propidium iodide–labeled cells increased from 27% to 43% of total cell count within 1–7 h after preparation of slices. Compared with these untreated control slices, cyanide-induced anoxia (30 min) or aglycemia (1 h) did not cause further cell death, whereas 3-h aglycemia destroyed an additional 13% of cells. Ischemia (1 h) due to cyanide plus iodoacetate immediately labeled an additional 20% of cells, and an additional 48% of cells were destroyed within the following 3 h of postischemia. Continuous recording of propidium iodide fluorescence showed that loss of membrane integrity started within 25 min after onset of the ischemic depolarization and the concomitant intracellular Ca2+ rise. The results show that propidium iodide can be used to monitor cell death in acute brain slices. Our findings suggest that pronounced cell death occurs within a period of 1–4 h after onset of metabolic arrest and is apparently due to necrotic/oncotic mechanisms.

The Influence of Memory Load Upon Delay-Interval Activity in a Working-Memory Task: An Event-Related Functional MRI Study

2000 ◽  
Vol 12 (supplement 2) ◽  
pp. 90-105 ◽  
Author(s):  
Amishi P. Jha ◽  
Gregory McCarthy
Keyword(s):  
Delay Interval ◽  
Time Course ◽  
Memory Load ◽  
Memory Task ◽  
Recognition Task ◽  
Delay Period ◽  
Button Press ◽  
Memory Array ◽  
Baseline Levels ◽  
Delayed Recognition

We conducted two fMRI studies to investigate the sensitivity of delay-period activity to changes in memory load during a delayed-recognition task for faces. In Experiment 1, each trial began with the presentation of a memory array consisting of one, two, or three faces that lasted for 3 sec. A 15-sec delay period followed during which no stimuli were present. The delay interval concluded with a one-face probe to which subjects made a button press response indicating whether this face was part of the memory array. Experiment 2 was similar in design except that the delay period was lengthened to 24 sec, and the memory array consisted of only one or three faces. We hypothesized that memory maintenance processes that spanned the delay interval would be revealed by their sensitivity to memory load. Long delay intervals were employed to temporally dissociate phasic activity engendered by the memory array from sustained activity reflecting maintenance. Regions of interest (ROIs) were defined anatomically for the superior frontal gyri (SFG), middle frontal gyri (MFG), and inferior frontal gyri (IFG), intraparietal sulci (IPS), and fusiform gyri (FFG) on a subject-by-subject basis. The mean time course of activity was determined for all voxels within these regions and for that subset of voxels within each ROI that correlated significantly with an empirically determined reference waveform. In both experiments, memory load significantly influenced activation 6-9 sec following the onset of the memory array with larger amplitude responses for higher load levels. Responses were greatest within MFG, IPS, and FFG. In both experiments, however, these load-sensitive differences declined over successive time intervals and were no longer significant at the end of the delay interval. Although insensitive to our load manipulation, sustained activation was present at the conclusion of the delay interval within MFG and other prefrontal regions. IPS delay activity returned to prestimulus baseline levels prior to the end of the delay period in Experiment 2, but not in Experiment 1. Within FFG, delay activity returned to prestimulus baseline levels prior to the conclusion of the delay interval in both experiments. Thus, while phasic processes engendered by the memory array were strongly affected by memory load, no evidence for load-sensitive delay-spanning maintenance processes was obtained.

Preservation of Cognitive Procedural Memory in a Case of Korsakoff's Syndrome: Methodological and Theoretical Insights

1998 ◽  
Vol 86 (3_suppl) ◽  
pp. 1267-1287 ◽  
Author(s):  
Hélène Beaunieux ◽  
Béatrice Desgranges ◽  
Catherine Lalevée ◽  
Vincent De La Sayette ◽  
Bernard Lechevalier ◽  
...  
Keyword(s):  
Working Memory ◽  
Procedural Knowledge ◽  
Declarative Memory ◽  
Procedural Memory ◽  
Korsakoff’S Syndrome ◽  
Tower Of Hanoi ◽  
Procedural Task ◽  
Korsakoff's Syndrome

Using the Tower of Hanoï puzzle, Butters, et al. in 1985 illustrated the difficulties in learning the procedure and questioned the suitability of this task for the assessment of the cognitive procedural memory in Korsakoff's syndrome. Our objective, in the light of these criticisms, was to show preservation of cognitive procedural capacities with the Tower of Hanoï for a man (P.F.) who was suffering from alcoholic Korsakoff's syndrome. For this procedural task, some aids helped to compensate in part for the difficulties with declarative memory and with working memory. In this condition, P.F. was able to learn the cognitive procedure. This study suggests that cognitive procedural memory may be preserved in some patients suffering from Korsakoff's syndrome and that this may be shown when a suitable task is used The result makes it possible to discuss the interaction between declarative and procedural knowledge in the solving of the Tower of Hanoï.

Neuronal Synchronization and Selective Color Processing in the Human Brain

2004 ◽  
Vol 16 (3) ◽  
pp. 503-522 ◽  
Author(s):  
Matthias M. Müller ◽  
Andreas Keil
Keyword(s):  
Large Scale ◽  
Time Course ◽  
Time Window ◽  
Brain Activity ◽  
Stimulus Onset ◽  
Gamma Band ◽  
Event Related Potential ◽  
Alpha Band ◽  
Color Processing ◽  
The Time Domain

In the present study, subjects selectively attended to the color of checkerboards in a feature-based attention paradigm. Induced gamma band responses (GBRs), the induced alpha band, and the event-related potential (ERP) were analyzed to uncover neuronal dynamics during selective feature processing. Replicating previous ERP findings, the selection negativity (SN) with a latency of about 160 msec was extracted. Furthermore, and similarly to previous EEG studies, a gamma band peak in a time window between 290 and 380 msec was found. This peak had its major energy in the 55to 70-Hz range and was significantly larger for the attended color. Contrary to previous human induced gamma band studies, a much earlier 40to 50-Hz peak in a time window between 160 and 220 msec after stimulus onset and, thus, concurrently to the SN was prominent with significantly more energy for attended as opposed to unattended color. The induced alpha band (9.8–11.7 Hz), on the other hand, exhibited a marked suppression for attended color in a time window between 450 and 600 msec after stimulus onset. A comparison of the time course of the 40to 50-Hz and 55to 70-Hz induced GBR, the induced alpha band, and the ERP revealed temporal coincidences for changes in the morphology of these brain responses. Despite these similarities in the time domain, the cortical source configuration was found to discriminate between induced GBRs and the SN. Our results suggest that large-scale synchronous high-frequency brain activity as measured in the human GBR play a specific role in attentive processing of stimulus features.

scholarly journals A Structured ICA-based Process for Removing Auditory Evoked Potentials Reveals TMS-evoked Potentials and TMS-modulated Oscillations

2021 ◽  
Author(s):  
Jessica M. Ross ◽  
Recep A. Ozdemir ◽  
Shu Jing Lian ◽  
Peter J. Fried ◽  
Eva M. Schmitt ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Time Course ◽  
Auditory Evoked Potentials ◽  
Time Window ◽  
Auditory Evoked Potential ◽  
Cosine Similarity ◽  
Similarity Analysis ◽  
Stimulation Site ◽  
Individual Subject ◽  
Site Specific

Abstract Background: Transcranial magnetic stimulation (TMS)-evoked potentials (TEPs), recorded using electroencephalography (EEG), reflect a combination of TMS-induced cortical activity and multi-sensory responses to TMS. The auditory evoked potential (AEP) is a high-amplitude sensory potential—evoked by the “click” sound produced by every TMS pulse—that can dominate the TEP and obscure observation of other neural components. The AEP is peripherally evoked and therefore should not be stimulation site specificObjectives/Methods: We address the problem of disentangling the peripherally evoked AEP of the TEP from components evoked by cortical stimulation and ask whether removal of AEP enables more accurate isolation of TEP. We hypothesized that isolation of the AEP using Independent Components Analysis (ICA) would reveal features that are stimulation site specific and unique individual features. In order to improve the effectiveness of ICA for removal of AEP from the TEP, and thus more clearly separate the transcranial-evoked and non-specific TMS-modulated potentials, we merged sham and active TMS datasets representing multiple stimulation conditions, removed the resulting AEP component, and evaluated performance across different sham protocols and clinical populations using reduction in Global and Local Mean Field Potentials (GMFA/LMFA) and cosine similarity analysis.Results: We show that removing AEPs significantly reduced GMFA and LMFA in the post-stimulation TEP (14 to 400 ms), driven by time windows consistent with the N100 and P200 temporal characteristics of AEPs. Cosine similarity analysis supports that removing AEPs reduces TEP similarity between subjects and reduces TEP similarity between stimulation conditions. Similarity is reduced most in a mid-latency window consistent with the N100 time-course, but nevertheless remains high in this time window. Residual TEP in this window has a time-course and topography unique from AEPs, which follow-up analyses suggest could be a modulation in the alpha band that is not stimulation site specific but is unique to individual subject.Conclusion(s): We show, using two datasets and two implementations of sham, evidence in cortical topography, TEP time-course, GMFA/LMFA and cosine similarity analyses that this procedure is effective and conservative in removing the AEP from TEP, and thereby reveals better defined TMS-evoked activity. We show TEP remaining in early, mid and late latencies. The early response is site and subject specific. Later responses are consistent with TMS-modulated alpha activity that is not site specific but is unique to the individual. TEP remaining after removal of AEP is unique and can provide insight into TMS-evoked potentials and other modulated oscillatory dynamics.

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