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Theta oscillation

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https://www.readbyqxmd.com/read/29154132/dexmedetomidine-promotes-biomimetic-non-rapid-eye-movement-stage-3-sleep-in-humans-a-pilot-study
#1
Oluwaseun Akeju, Lauren E Hobbs, Lei Gao, Sara M Burns, Kara J Pavone, George S Plummer, Elisa C Walsh, Tim T Houle, Seong-Eun Kim, Matt T Bianchi, Jeffrey M Ellenbogen, Emery N Brown
OBJECTIVES: Sleep, which comprises of rapid eye movement (REM) and non-REM stages 1-3 (N1-N3), is a natural occurring state of decreased arousal that is crucial for normal cardiovascular, immune and cognitive function. The principal sedative drugs produce electroencephalogram beta oscillations, which have been associated with neurocognitive dysfunction. Pharmacological induction of altered arousal states that neurophysiologically approximate natural sleep, termed biomimetic sleep, may eliminate drug-induced neurocognitive dysfunction...
October 20, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29153327/auditory-sensitivity-and-decision-criteria-oscillate-at-different-frequencies-separately-for-the-two-ears
#2
Hao Tam Ho, Johahn Leung, David C Burr, David Alais, Maria Concetta Morrone
Many behavioral measures of visual perception fluctuate continually in a rhythmic manner, reflecting the influence of endogenous brain oscillations, particularly theta (∼4-7 Hz) and alpha (∼8-12 Hz) rhythms [1-3]. However, it is unclear whether these oscillations are unique to vision or whether auditory performance also oscillates [4, 5]. Several studies report no oscillatory modulation in audition [6, 7], while those with positive findings suffer from confounds relating to neural entrainment [8-10]. Here, we used a bilateral pitch-identification task to investigate rhythmic fluctuations in auditory performance separately for the two ears and applied signal detection theory (SDT) to test for oscillations of both sensitivity and criterion (changes in decision boundary) [11, 12]...
November 10, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/29146376/wronger-than-wrong-graded-mapping-of-the-errors-of-an-avatar-in-the-performance-monitoring-system-of-the-onlooker
#3
G Spinelli, G Tieri, E F Pavone, S M Aglioti
EEG studies show that observing errors in one's own or others' actions triggers specific electro-cortical signatures in the onlooker's brain, but whether the brain error-monitoring system operates according to graded or discrete rules is still largely unknown. To explore this issue, we combined immersive virtual reality with EEG recording in participants who observed an avatar reaching-to-grasp a glass from a first-person perspective. The avatar could perform correct or erroneous actions. Erroneous grasps were defined as small or large depending on the magnitude of the trajectory deviation from the to-be-grasped glass...
November 13, 2017: NeuroImage
https://www.readbyqxmd.com/read/29145567/influence-of-airflow-rate-and-stimulus-concentration-on-olfactory-event-related-potentials-oerp-in-humans
#4
Pengfei Han, Valentin A Schriever, Per Peters, Heidi Olze, Florian C Uecker, Thomas Hummel
Although the association between odor concentration and olfactory event-related potential (OERP) has been studied, less is known about the influence of airflow on OERP. The aim of this study was to investigate the influence of airflow rate and stimulus concentration on OERP in humans. EEG data were collected from young healthy volunteers (n=17) in separate sessions where 2-phenylethanol (PEA) was delivered in the following conditions: 8L/min 50%v/v, 8L/min 30%v/v, 4L/min 100%v/v and 4L/min 60%v/v. Odor concentrations are referred to the %v/v achieved with air dilution and was not measured in the nose...
November 14, 2017: Chemical Senses
https://www.readbyqxmd.com/read/29142322/bilateral-5%C3%A2-hz-transcranial-alternating-current-stimulation-on-fronto-temporal-areas-modulates-resting-state-eeg
#5
Aurora D'Atri, Claudia Romano, Maurizio Gorgoni, Serena Scarpelli, Valentina Alfonsi, Michele Ferrara, Fabio Ferlazzo, Paolo Maria Rossini, Luigi De Gennaro
Rhythmic non-invasive brain stimulations are promising tools to modulate brain activity by entraining neural oscillations in specific cortical networks. The aim of the study was to assess the possibility to influence the neural circuits of the wake-sleep transition in awake subjects via a bilateral transcranial alternating current stimulation at 5 Hz (θ-tACS) on fronto-temporal areas. 25 healthy volunteers participated in two within-subject sessions (θ-tACS and sham), one week apart and in counterbalanced order...
November 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29132379/effects-of-somatosensory-electrical-stimulation-on-motor-function-and-cortical-oscillations
#6
Adelyn P Tu-Chan, Nikhilesh Natraj, Jason Godlove, Gary Abrams, Karunesh Ganguly
BACKGROUND: Few patients recover full hand dexterity after an acquired brain injury such as stroke. Repetitive somatosensory electrical stimulation (SES) is a promising method to promote recovery of hand function. However, studies using SES have largely focused on gross motor function; it remains unclear if it can modulate distal hand functions such as finger individuation. OBJECTIVE: The specific goal of this study was to monitor the effects of SES on individuation as well as on cortical oscillations measured using EEG, with the additional goal of identifying neurophysiological biomarkers...
November 13, 2017: Journal of Neuroengineering and Rehabilitation
https://www.readbyqxmd.com/read/29131743/integration-and-temporal-processing-of-asynchronous-audiovisual-speech
#7
David M Simon, Mark T Wallace
Multisensory integration of visual mouth movements with auditory speech is known to offer substantial perceptual benefits, particularly under challenging (i.e., noisy) acoustic conditions. Previous work characterizing this process has found that ERPs to auditory speech are of shorter latency and smaller magnitude in the presence of visual speech. We sought to determine the dependency of these effects on the temporal relationship between the auditory and visual speech streams using EEG. We found that reductions in ERP latency and suppression of ERP amplitude are maximal when the visual signal precedes the auditory signal by a small interval and that increasing amounts of asynchrony reduce these effects in a continuous manner...
November 13, 2017: Journal of Cognitive Neuroscience
https://www.readbyqxmd.com/read/29130551/a-localized-pallidal-physiomarker-in-cervical-dystonia
#8
Wolf-Julian Neumann, Andreas Horn, Siobhan Ewert, Julius Huebl, Christof Brücke, Colleen Slentz, Gerd-Helge Schneider, Andrea A Kühn
OBJECTIVE: Deep brain stimulation (DBS) allows for direct recordings of neuronal activity from the human basal ganglia. In Parkinson's disease, a disease-specific physiomarker was identified that is now used to investigate adaptive closed-loop stimulation in first studies. In dystonia such a physiomarker is missing. METHODS: Pallidal oscillations were recorded from 153 contact pairs in 27 patients. We investigated whether power amplitudes in theta and beta bands correlate with dystonic symptom severity across patients...
November 11, 2017: Annals of Neurology
https://www.readbyqxmd.com/read/29124791/impact-of-different-intensities-of-intermittent-theta-burst-stimulation-on-the-cortical-properties-during-tms-eeg-and-working-memory-performance
#9
Sung Wook Chung, Nigel C Rogasch, Kate E Hoy, Caley M Sullivan, Robin F H Cash, Paul B Fitzgerald
Intermittent theta burst stimulation (iTBS) is a noninvasive brain stimulation technique capable of increasing cortical excitability beyond the stimulation period. Due to the rapid induction of modulatory effects, prefrontal application of iTBS is gaining popularity as a therapeutic tool for psychiatric disorders such as depression. In an attempt to increase efficacy, higher than conventional intensities are currently being applied. The assumption that this increases neuromodulatory may be mechanistically false for iTBS...
November 9, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/29118106/sleep-in-humans-stabilizes-pattern-separation-performance
#10
A Hanert, F D Weber, A Pedersen, J Born, T Bartsch
Replay of hippocampal neural representations during sleep is thought to promote systems consolidation of declarative memory. How this reprocessing of memory during sleep affects the hippocampal representation itself, is unclear. Here we tested hippocampal stimulus processing, i.e., pattern separation, before and after periods of sleep and wakefulness in humans (female and male participants). Pattern separation deteriorated across the wake period but remained stable across sleep (p = .013) with this sleep-wake difference being most pronounced for stimuli with low similarity to targets (p = ...
November 8, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29118102/phencyclidine-discoordinates-hippocampal-network-activity-but-not-place-fields
#11
Hsin-Yi Kao, Dino Dvořák, EunHye Park, Jana Kenney, Eduard Kelemen, André A Fenton
We used the psychotomimetic phencyclidine (PCP) to investigate the relationships between cognitive behavior, coordinated neural network function and information processing within the hippocampus place cell system. We report in rats that PCP (5mg/kg i.p.) impairs a well-learned hippocampus-dependent place avoidance behavior in rats that requires cognitive control, even when PCP is injected directly into dorsal hippocampus. PCP increases 60-100 Hz medium gamma oscillations in hippocampus CA1 and these increases correlate with the cognitive impairment caused by systemic PCP administration...
November 8, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29109512/modulating-medial-septal-cholinergic-activity-reduces-medial-entorhinal-theta-frequency-without-affecting-speed-or-grid-coding
#12
Francis Carpenter, Neil Burgess, Caswell Barry
Medial septal inputs to the hippocampal system are crucial for aspects of temporal and spatial processing, such as theta oscillations and grid cell firing. However, the precise contributions of the medial septum's cholinergic neurones to these functions remain unknown. Here, we recorded neuronal firing and local field potentials from the medial entorhinal cortex of freely foraging mice, while modulating the excitability of medial septal cholinergic neurones. Alteration of cholinergic activity produced a reduction in the frequency of theta oscillations, without affecting the slope of the non-linear theta frequency vs running speed relationship observed...
November 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29103999/improving-the-quality-of-combined-eeg-tms-neural-recordings-introducing-the-coil-spacer
#13
K L Ruddy, D G Woolley, D Mantini, J H Balsters, N Enz, N Wenderoth
BACKGROUND: In the last decade, interest in combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) approaches has grown substantially. Aside from the obvious artifacts induced by the magnetic pulses themselves, separate and more sinister signal disturbances arise as a result of contact between the TMS coil and EEG electrodes. NEW METHOD: Here we profile the characteristics of these artifacts and introduce a simple device - the coil spacer - to provide a platform allowing physical separation between the coil and electrodes during stimulation...
November 6, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/29094462/functional-integration-across-oscillation-frequencies-by-cross-frequency-phase-synchronization
#14
J Matias Palva, Satu Palva
Neuronal oscillations and their inter-areal synchronization may be instrumental in regulating neuronal communication in distributed networks. Several lines of research have, however, shown that cognitive tasks engage neuronal oscillations simultaneously in multiple frequency bands that have distinct functional roles in cognitive processing. Gamma oscillations (30-120 Hz) are associated with bottom-up processing while slower oscillations in delta (1-4 Hz), theta- (4-7Hz), alpha (8-14 Hz), and beta (14-30 Hz) frequency bands may have roles in executive or top-down controlling functions, although also other distinctions have been made...
November 2, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29092130/independently-tunable-dual-wavelength-fiber-oscillator-with-synchronized-pulsed-emission-based-on-a-theta-ring-cavity-and-a-fiber-bragg-grating-array
#15
Tobias Tiess, Martin Becker, Manfred Rothhardt, Hartmut Bartelt, Matthias Jäger
We present a fiber-integrated laser enabling independent tuning of two emission wavelengths with a synchronized pulsed emission. The discrete tuning concept comprises a theta cavity fiber laser (TCFL), a fiber Bragg grating (FBG) array as a versatile spectral filter, facilitating tailored tuning ranges, and optical gating to control the emission spectrum. A novel electrical driving scheme uniquely enables independently tunable multi-wavelength emission from a single laser oscillator. Tunable dual-wavelength emission is experimentally investigated with a ytterbium (Yb)-doped TCFL using an FBG array with 11 gratings...
October 30, 2017: Optics Express
https://www.readbyqxmd.com/read/29089911/frontal-theta-activity-supports-detecting-mismatched-information-in-visual-working-memory
#16
Tengfei Liang, Zhonghua Hu, Qiang Liu
During the comparison stage of visual working memory (VWM) processing, detecting the mismatch between the external sensory input and internal representations is a crucial cognitive ability for human, but the neural mechanism behind it remains largely unclear. The present study investigated the role of frontal theta power in detecting the mismatched information in VWM in a delayed matching task. A control task required to compare two simultaneously presented visual figures was also designed as a contrast to exclude the possibility that frontal theta activity just reflecting the non-memory-related behavioral conflicts...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/29081745/changes-of-functional-and-directed-resting-state-connectivity-are-associated-with-neuronal-oscillations-apoe-genotype-and-amyloid-deposition-in-mild-cognitive-impairment
#17
Lars Michels, Muthuraman Muthuraman, Abdul R Anwar, Spyros Kollias, Sandra E Leh, Florian Riese, Paul G Unschuld, Michael Siniatchkin, Anton F Gietl, Christoph Hock
The assessment of effects associated with cognitive impairment using electroencephalography (EEG) power mapping allows the visualization of frequency-band specific local changes in oscillatory activity. In contrast, measures of coherence and dynamic source synchronization allow for the study of functional and effective connectivity, respectively. Yet, these measures have rarely been assessed in parallel in the context of mild cognitive impairment (MCI) and furthermore it has not been examined if they are related to risk factors of Alzheimer's disease (AD) such as amyloid deposition and apolipoprotein ε4 (ApoE) allele occurrence...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/29079799/emergence-of-early-alterations-in-network-oscillations-and-functional-connectivity-in-a-tau-seeding-mouse-model-of-alzheimer-s-disease-pathology
#18
A Ahnaou, D Moechars, L Raeymaekers, R Biermans, N V Manyakov, A Bottelbergs, C Wintmolders, K Van Kolen, T Van De Casteele, J A Kemp, W H Drinkenburg
Synaptic dysfunction and disconnectivity are core deficits in Alzheimer's disease (AD), preceding clear changes in histopathology and cognitive functioning. Here, the early and late effects of tau pathology induction on functional network connectivity were investigated in P301L mice. Multichannel EEG oscillations were used to compute (1) coherent activity between the prefrontal cortex (PFC) and hippocampus (HPC) CA1-CA3 networks; (2) phase-amplitude cross frequency coupling (PAC) between theta and gamma oscillations, which is instrumental in adequate cognitive functioning; (3) information processing as assessed by auditory evoked potentials and oscillations in the passive oddball mismatch negativity-like (MMN) paradigm...
October 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29078334/human-hippocampal-theta-power-indicates-movement-onset-and-distance-travelled
#19
Daniel Bush, James A Bisby, Chris M Bird, Stephanie Gollwitzer, Roman Rodionov, Beate Diehl, Andrew W McEvoy, Matthew C Walker, Neil Burgess
Theta frequency oscillations in the 6- to 10-Hz range dominate the rodent hippocampal local field potential during translational movement, suggesting that theta encodes self-motion. Increases in theta power have also been identified in the human hippocampus during both real and virtual movement but appear as transient bursts in distinct high- and low-frequency bands, and it is not yet clear how these bursts relate to the sustained oscillation observed in rodents. Here, we examine depth electrode recordings from the temporal lobe of 13 presurgical epilepsy patients performing a self-paced spatial memory task in a virtual environment...
October 24, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29066322/alterations-in-mesoscopic-oscillations-affecting-episodic-memory-following-developmental-traumatic-brain-injury
#20
Chaitali Biswas, Dejan Marković, Christopher C Giza
Certain deficits of episodic memory among young adults are the delayed consequences of an earlier mild or moderate Traumatic Brain Injury (mTBI). We examined alterations in hippocampal Local Field Oscillations (LFOs) of equivalently-impaired juvenile rodents to identify reliable functional markers of single-incidence mTBI. Two persistent, behavior-dependent, electrophysiological markers of injury were identified in the absence of external physiological symptoms by the analysis of wirelessly-transmitted hippocampal LFOs (3-80Hz) during repeat measures of the Novel Object Recognition (NOR) paradigm...
October 21, 2017: Experimental Neurology
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