keyword
MENU ▼
Read by QxMD icon Read
search

Gamma rhythm

keyword
https://www.readbyqxmd.com/read/27886711/eeg-epochs-with-less-alpha-rhythm-improve-discrimination-of-mild-alzheimer-s
#1
Paulo A M Kanda, Eliezyer F Oliveira, Francisco J Fraga
BACKGROUND AND OBJECTIVE: Eyes-closed-awake electroencephalogram (EEG) is a useful tool in the diagnosis of Alzheimer's. However, there is eyes-closed-awake EEG with dominant or rare alpha rhythm. In this paper, we show that random selection of EEG epochs disregarding the alpha rhythm will lead to bias concerning EEG-based Alzheimer's Disease diagnosis. METHODS: We compared EEG epochs with more than 30% and with less than 30% alpha rhythm of mild Alzheimer's Disease patients and healthy elderly...
January 2017: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/27881788/brain-network-mechanisms-underlying-motor-enhancement-by-transcranial-entrainment-of-gamma-oscillations
#2
Marius Moisa, Rafael Polania, Marcus Grueschow, Christian C Ruff
: Gamma and beta oscillations are routinely observed in motor-related brain circuits during movement preparation and execution. Entrainment of gamma or beta oscillations via transcranial alternating current stimulation (tACS) over primary motor cortex (M1) has opposite effects on motor performance, suggesting a causal role of these brain rhythms for motor control. However, it is largely unknown which brain mechanisms characterize these changes in motor performance brought about by tACS...
November 23, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27830753/lucky-rhythms-in-orbitofrontal-cortex-bias-gambling-decisions-in-humans
#3
Pierre Sacré, Matthew S D Kerr, Kevin Kahn, Jorge Gonzalez-Martinez, Juan Bulacio, Hyun-Joo Park, Matthew A Johnson, Susan Thompson, Jaes Jones, Vikram S Chib, John T Gale, Sridevi V Sarma
It is well established that emotions influence our decisions, yet the neural basis of this biasing effect is not well understood. Here we directly recorded local field potentials from the OrbitoFrontal Cortex (OFC) in five human subjects performing a financial decision-making task. We observed a striking increase in gamma-band (36-50 Hz) oscillatory activity that reflected subjects' decisions to make riskier choices. Additionally, these gamma rhythms were linked back to mismatched expectations or "luck" occurring in past trials...
November 10, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27802274/topology-cross-frequency-and-same-frequency-band-interactions-shape-the-generation-of-phase-amplitude-coupling-in-a-neural-mass-model-of-a-cortical-column
#4
Roberto C Sotero
Phase-amplitude coupling (PAC), a type of cross-frequency coupling (CFC) where the phase of a low-frequency rhythm modulates the amplitude of a higher frequency, is becoming an important indicator of information transmission in the brain. However, the neurobiological mechanisms underlying its generation remain undetermined. A realistic, yet tractable computational model of the phenomenon is thus needed. Here we analyze a neural mass model of a cortical column, comprising fourteen neuronal populations distributed across four layers (L2/3, L4, L5 and L6)...
November 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27790169/large-scale-functional-brain-networks-underlying-temporal-integration-of-audio-visual-speech-perception-an-eeg-study
#5
G Vinodh Kumar, Tamesh Halder, Amit K Jaiswal, Abhishek Mukherjee, Dipanjan Roy, Arpan Banerjee
Observable lip movements of the speaker influence perception of auditory speech. A classical example of this influence is reported by listeners who perceive an illusory (cross-modal) speech sound (McGurk-effect) when presented with incongruent audio-visual (AV) speech stimuli. Recent neuroimaging studies of AV speech perception accentuate the role of frontal, parietal, and the integrative brain sites in the vicinity of the superior temporal sulcus (STS) for multisensory speech perception. However, if and how does the network across the whole brain participates during multisensory perception processing remains an open question...
2016: Frontiers in Psychology
https://www.readbyqxmd.com/read/27764592/selective-interareal-synchronization-through-gamma-frequency-differences-and-slower-rhythm-gamma-phase-reset
#6
Thomas Burwick, Alexandros Bouras
The communication-through-coherence (CTC) hypothesis states that a sending group of neurons will have a particularly strong effect on a receiving group if both groups oscillate in a phase-locked ("coherent") manner (Fries, 2005, 2015). Here, we consider a situation with two visual stimuli, one in the focus of attention and the other distracting, resulting in two sites of excitation at an early cortical area that project to a common site in a next area. Taking a modeler's perspective, we confirm the workings of a mechanism that was proposed by Bosman et al...
October 20, 2016: Neural Computation
https://www.readbyqxmd.com/read/27718535/the-rhythm-of-the-executive-gate-of-speech-subthalamic-low-frequency-oscillations-increase-during-verbal-generation
#7
Lars Wojtecki, Saskia Elben, Jan Vesper, Alfons Schnitzler
We investigated neurophysiological mechanisms of subthalamic nucleus involvement in verbal fluency by means of a verbal generation task. The subthalamic nucleus is thought to act as a behavioural go/no-go instance by means of oscillatory communication in theta band with the prefrontal cortex. Because subthalamic alpha-theta frequency stimulation has been shown to exert beneficial effects on verbal fluency in Parkinson's disease, we hypothesized that an alpha-theta oscillatory network involving the subthalamic nucleus underlies verbal generation task performance as a gating instance for speech execution...
October 8, 2016: European Journal of Neuroscience
https://www.readbyqxmd.com/read/27713698/stress-assessment-by-prefrontal-relative-gamma
#8
Jesus Minguillon, Miguel A Lopez-Gordo, Francisco Pelayo
Stress assessment has been under study in the last years. Both biochemical and physiological markers have been used to measure stress level. In neuroscience, several studies have related modification of stress level to brain activity changes in limbic system and frontal regions, by using non-invasive techniques such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). In particular, previous studies suggested that the exhibition or inhibition of certain brain rhythms in frontal cortical areas indicates stress...
2016: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/27693609/neural-oscillations-as-a-bridge-between-glutamatergic-system-and-emotional-behaviors-in-simulated-microgravity-induced-mice
#9
Xueliang Shang, Bo Xu, Qun Li, Baohui Zhai, Xiaxia Xu, Tao Zhang
This study aims to investigate if neural oscillations can play a role as a bridge between the alteration of glutamatergic system and emotional behaviors in simulated microgravity (SM) mice. Adult male C57BL/6J mice were randomly divided into two groups: SM and control groups. The animal model was established by hindlimb unloading (HU). The mice were exposed to HU continued for 14days. Weight and sucrose consumption were measured. The degree of anxious and depressive was evaluated by Open field test and Elevated plus maze test...
September 28, 2016: Behavioural Brain Research
https://www.readbyqxmd.com/read/27667008/gamma-rhythmic-gain-modulation
#10
Jianguang Ni, Thomas Wunderle, Christopher Murphy Lewis, Robert Desimone, Ilka Diester, Pascal Fries
Cognition requires the dynamic modulation of effective connectivity, i.e., the modulation of the postsynaptic neuronal response to a given input. If postsynaptic neurons are rhythmically active, this might entail rhythmic gain modulation, such that inputs synchronized to phases of high gain benefit from enhanced effective connectivity. We show that visually induced gamma-band activity in awake macaque area V4 rhythmically modulates responses to unpredictable stimulus events. This modulation exceeded a simple additive superposition of a constant response onto ongoing gamma-rhythmic firing, demonstrating the modulation of multiplicative gain...
October 5, 2016: Neuron
https://www.readbyqxmd.com/read/27660457/the-association-of-serum-gamma-glutamyl-transpeptidase-level-and-other-laboratory-parameters-with-blood-pressure-in-hypertensive-patients-under-ambulatory-blood-pressure-monitoring
#11
Adile Ortakoyluoglu, Betul Boz, Oguzhan Sıtkı Dizdar, Deniz Avcı, Ali Cetinkaya, Osman Baspınar
BACKGROUND: Hypertension is a very important cause of morbidity and mortality. Serum gamma-glutamyl transpeptidase (GGT) is a biomarker of oxidative stress and associated with increased risk of hypertension and diabetes. The aim of this study was to evaluate the association of serum GGT level, which is an early marker of inflammation and endothelial dysfunction, with the deterioration of the diurnal rhythm of the blood pressure. METHODS: A total of 171 patients with hypertension were included in this study...
2016: Therapeutics and Clinical Risk Management
https://www.readbyqxmd.com/read/27651114/circadian-dynamics-in-measures-of-cortical-excitation-and-inhibition-balance
#12
Sarah L Chellappa, Giulia Gaggioni, Julien Q M Ly, Soterios Papachilleos, Chloé Borsu, Alexandre Brzozowski, Mario Rosanova, Simone Sarasso, André Luxen, Benita Middleton, Simon N Archer, Derk-Jan Dijk, Marcello Massimini, Pierre Maquet, Christophe Phillips, Rosalyn J Moran, Gilles Vandewalle
Several neuropsychiatric and neurological disorders have recently been characterized as dysfunctions arising from a 'final common pathway' of imbalanced excitation to inhibition within cortical networks. How the regulation of a cortical E/I ratio is affected by sleep and the circadian rhythm however, remains to be established. Here we addressed this issue through the analyses of TMS-evoked responses recorded over a 29 h sleep deprivation protocol conducted in young and healthy volunteers. Spectral analyses of TMS-evoked responses in frontal cortex revealed non-linear changes in gamma band evoked oscillations, compatible with an influence of circadian timing on inhibitory interneuron activity...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27636199/gamma-synchronization-influences-map-formation-time-in-a-topological-model-of-spatial-learning
#13
Edward Basso, Mamiko Arai, Yuri Dabaghian
The mammalian hippocampus plays a crucial role in producing a cognitive map of space-an internalized representation of the animal's environment. We have previously shown that it is possible to model this map formation using a topological framework, in which information about the environment is transmitted through the temporal organization of neuronal spiking activity, particularly those occasions in which the firing of different place cells overlaps. In this paper, we discuss how gamma rhythm, one of the main components of the extracellular electrical field potential affects the efficiency of place cell map formation...
September 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27628206/slow-gamma-rhythms-in-ca3-are-entrained-by-slow-gamma-activity-in-the-dentate-gyrus
#14
Yi-Tse Hsiao, Chenguang Zheng, Laura Lee Colgin
In hippocampal area CA1, slow (~25-55 Hz) and fast (~60-100 Hz) gamma rhythms are coupled with different CA1 afferents. CA1 slow gamma is coupled to inputs from CA3, and CA1 fast gamma is coupled to inputs from the medial entorhinal cortex (Colgin et al. 2009). CA3 gives rise to highly divergent associational projections, and it is possible that reverberating activity in these connections generates slow gamma rhythms in the hippocampus. However, hippocampal gamma is maximal upstream of CA3, in the dentate gyrus (DG) region (Bragin et al...
September 14, 2016: Journal of Neurophysiology
https://www.readbyqxmd.com/read/27559180/training-working-memory-in-childhood-enhances-coupling-between-frontoparietal-control-network-and-task-related-regions
#15
Jessica J Barnes, Anna Christina Nobre, Mark W Woolrich, Kate Baker, Duncan E Astle
UNLABELLED: Working memory is a capacity upon which many everyday tasks depend and which constrains a child's educational progress. We show that a child's working memory can be significantly enhanced by intensive computer-based training, relative to a placebo control intervention, in terms of both standardized assessments of working memory and performance on a working memory task performed in a magnetoencephalography scanner. Neurophysiologically, we identified significantly increased cross-frequency phase amplitude coupling in children who completed training...
August 24, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27540962/from-mild-cognitive-impairment-to-alzheimer-s-disease-a-new-perspective-in-the-land-of-human-brain-reactivity-and-connectivity
#16
Paolo Maria Rossini, Riccardo Di Iorio, Giuseppe Granata, Francesca Miraglia, Fabrizio Vecchio
In a recent study, analyzing the modulation of γ-band oscillations, Naro and colleagues demonstrated that transcranial alternating current stimulation could drive the gamma rhythms in the human EEG in cognitive healthy elderly subjects but not in mild cognitive impairment (MCI) prodromal to Alzheimer's disease (AD) and in early AD patients. Therefore, this method is proposed to intercept early in the disease course those MCI subjects who are in a pre-symptomatic stage of an already established AD. This prediction index may help the clinician to adopt a better prevention/follow-up strategy...
July 14, 2016: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/27536227/phase-amplitude-coupling-is-elevated-in-deep-sleep-and-in-the-onset-zone-of-focal-epileptic-seizures
#17
Mina Amiri, Birgit Frauscher, Jean Gotman
The interactions between different EEG frequency bands have been widely investigated in normal and pathologic brain activity. Phase-amplitude coupling (PAC) is one of the important forms of this interaction where the amplitude of higher frequency oscillations is modulated by the phase of lower frequency activity. Here, we studied the dynamic variations of PAC of high (gamma and ripple) and low (delta, theta, alpha, and beta) frequency bands in patients with focal epilepsy in different sleep stages during the interictal period, in an attempt to see if coupling is different in more or less epileptogenic regions...
2016: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/27491166/-the-correction-with-noophen-of-autonomic-dysfunction-in-young-men-with-hypertension
#18
I I Knyazkova, N V Kuzminova, N Yu Osovskaya
The aim of this study was to investigate the influence of antihypertensive therapy with adding of gamma-amino-beta-phenylbutyric acid hydrochloride on the autonornic regulation of tcardiovascular system and the psychoemotional status in young men with hypertension. The study included 58 male with hypertension, aged 18-39 years (mean age 31.7 yearst 2.3 years), of them 28 patients (group I) administered beta-blocker and the other received a complex therapy which included beta-blocker and gamma-amino-beta-phenylbutyric acid hydrochiotide--Noofen ("OlainFarm", Latvia) 250 mg 3 times a day for 4 weeks...
October 2015: Likars'ka Sprava
https://www.readbyqxmd.com/read/27443853/cortical-activity-modulations-underlying-age-related-performance-differences-during-posture-cognition-dual-tasking
#19
Recep A Ozdemir, Jose L Contreras-Vidal, Beom-Chan Lee, William H Paloski
To date, no systematic research investigating cortical correlates of performance changes in dual tasking has been reported in the elderly population. Thus, we monitored whole-scalp cortical activations (EEG) during both single task and posture-cognition dual tasking with the main goal of understanding cortical activity modulations underlying age-related differences on posture-cognition dual tasking conditions. Postural and cognitive data analyses showed that elderly people had decreased cognitive performance even during challenging single cognitive tasks...
July 21, 2016: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/27432759/what-can-be-found-in-scalp-eeg-spectrum-beyond-common-frequency-bands-eeg-fmri-study
#20
R Marecek, M Lamos, M Mikl, M Barton, J Fajkus, Rektor, M Brazdil
OBJECTIVE: The scalp EEG spectrum is a frequently used marker of neural activity. Commonly, the preprocessing of EEG utilizes constraints, e.g. dealing with a predefined subset of electrodes or a predefined frequency band of interest. Such treatment of the EEG spectrum neglects the fact that particular neural processes may be reflected in several frequency bands and/or several electrodes concurrently, and can overlook the complexity of the structure of the EEG spectrum. APPROACH: We showed that the EEG spectrum structure can be described by parallel factor analysis (PARAFAC), a method which blindly uncovers the spatial-temporal-spectral patterns of EEG...
August 2016: Journal of Neural Engineering
keyword
keyword
27169
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"