Gamma Oscillations Index Sustained Attention in a Brief Vigilance Task

Sustained attention is an essential behavior in life, but often leads to performance decrements with time. Computational accounts of sustained attention suggest this is due to brief disruptions in goal-directed processing, or microlapses. Decreases in gamma spectral power are a potential candidate for indexing microlapses and discriminating between low and high performers in sustained attention tasks, while increases in beta, alpha, and theta power are expected to exhibit compensatory effort to offset fatigue. The current study tests these hypotheses in a 10-minute Psychomotor Vigilance Test, a context that eliminates confounds with measuring gamma frequencies. 34 participants ( Mage = 22.60; SDage = 4.08) volunteered in the study. Results suggested frontal gamma power declined with time-on-task, indicating reduction in central cognition. Beta power increased with time-on-task, suggesting compensatory effort; however, alpha and theta power did not increase. Additionally, gamma power discriminated between low and high performers, potentially suggesting motivational differences between the groups.

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GABA-Glutamate supramammillary neurons control theta and gamma oscillations in the dentate gyrus during paradoxical (REM) sleep

10.1101/584862 ◽

2019 ◽

Cited By ~ 1

Author(s):

Francesca Billwiller ◽

Laura Castillo ◽

Heba Elseedy ◽

Anton Ivanovich Ivanov ◽

Jennyfer Scapula ◽

...

Keyword(s):

Dentate Gyrus ◽

Rem Sleep ◽

Slow Wave Sleep ◽

Granule Cells ◽

Structural Connectivity ◽

Gamma Oscillations ◽

Network Activity ◽

Projection Neurons ◽

Theta Power ◽

Gamma Power

AbstractSeveral studies suggest that neurons from the lateral region of the SuM (SuML) innervating the dorsal dentate gyrus (DG) display a dual GABAergic and glutamatergic transmission and are specifically activated during paradoxical (REM) sleep (PS). The objective of the present study is to fully characterize the anatomical, neurochemical and electrophysiological properties of the SuML-DG projection neurons and to determine how they control DG oscillations and neuronal activation during PS and other vigilance states. For this purpose, we combine structural connectivity techniques using neurotropic viral vectors (rabies virus, AAV), neurochemical anatomy (immunohistochemistry, in situ hybridization) and imaging (light, electron and confocal microscopy) with in vitro (patch clamp) and in vivo (LFP, EEG) optogenetic and electrophysiological recordings performed in transgenic VGLUT2-cre male mice. At the cellular level, we show that the SuML-DG neurons co-release GABA and glutamate on dentate granule cells and increase the activity of a subset of DG granule cells. At the network level, we show that activation of the SuML-DG pathway increases theta power and frequency during PS as well as gamma power during PS and waking in the DG. At the behavioral level, we show that the activation of this pathway does not change animal behavior during PS, induces awakening during slow wave sleep and increases motor activity during waking. These results suggest that the SuML-DG pathway is capable of supporting the increase of theta and gamma power in the DG observed during PS and plays an important modulatory role of DG network activity during this state.Significant statementAn increase of theta and gamma power in the dentate gyrus (DG) is an hallmark of paradoxical (REM) sleep (PS) and is suggested to promote learning and memory consolidation by synchronizing hippocampal networks and increasing its outputs to cortical targets. However the neuronal networks involved in such control of DG activity during PS are poorly understood. The present study identifies a population of GABA/Glutamate neurons in the lateral supramammllary nucleus (SuML) innervating the DG that could support such control during PS. Indeed, we show that activation of these SuML-DG projections increase theta power and frequency as well as gamma power in the DG specifically during PS and modulate activity of a subset of DG granule cells.

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The neural correlates of two forms of spiritual love: an EEG study

10.1101/045898 ◽

2016 ◽

Cited By ~ 2

Author(s):

E. S. Louise Faber

Keyword(s):

Neural Activity ◽

Emotional Experience ◽

Gamma Oscillations ◽

Neural Correlates ◽

Spiritual Practices ◽

Loving Kindness ◽

Beta Power ◽

Delta Activity ◽

Gamma Power ◽

The Brain

AbstractSpiritual practices are gaining an increasingly wider audience as a means to enhance positive affect in healthy individuals and to treat neurological disorders such as anxiety and depression. The current study aimed to examine the neural correlates of two different forms of love generated by spiritual practices using EEG; love generated during a loving kindness meditation performed by Buddhist meditators, and love generated during prayer, in a separate group of participants from a Christian-based faith. The loving kindness meditation was associated with significant increases in delta, alpha 1, alpha 2 and beta power compared to baseline, while prayer induced significant increases in power of alpha 1 and gamma oscillations, together with an increase in the gamma: theta ratio. An increase in delta activity occurred during the loving kindness meditation but not during prayer. In contrast increases in theta, alpha 1, alpha 2, beta and gamma power were observed when comparing both types of practice to baseline, suggesting that increases in these frequency bands are the neural correlates of spiritual love, independent of the type of practice used to attain the state of this type of love. These findings show that both spiritual love practices are associated with widespread changes in neural activity across the brain, in particular at frequency ranges that have been implicated in positive emotional experience, integration of distributed neural activity, and changes in short-term and longterm neural circuitry.

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High-gamma activity in the human hippocampus during inter-trial rest periods of a virtual navigation task

10.1101/252288 ◽

2018 ◽

Author(s):

Yi Pu ◽

Brian R. Cornwell ◽

Douglas Cheyne ◽

Blake W. Johnson

Keyword(s):

Gamma Oscillations ◽

Gamma Activity ◽

Training Set ◽

Virtual Navigation ◽

Navigation Task ◽

Theta Power ◽

Rest Periods ◽

Synthetic Aperture Magnetometry ◽

High Gamma ◽

Gamma Power

AbstractIn rodents, hippocampal cell assemblies formed during learning of a navigation task are observed to re-emerge during resting (offline) periods, accompanied by high-frequency oscillations (HFOs). This phenomenon is believed to reflect mechanisms for strengthening newly-formed memory traces. Using magnetoencephalography recordings and a beamforming source location algorithm (synthetic aperture magnetometry), we investigated high-gamma (80 – 140 Hz) oscillations in the hippocampal region in 18 human participants during inter-trial rest periods in a virtual navigation task. We found right hippocampal gamma oscillations mirrored the pattern of theta power in the same region during navigation, varying as a function of environmental novelty. Gamma power during inter-trial rest periods was positively correlated with theta power during navigation in the first training set when the environment was new and predicted faster learning in the subsequent training set two where the environment became familiar. These findings provide evidence for human hippocampal reactivation accompanied by high-gamma activities immediately after learning and establish a link between hippocampal high-gamma activities and memory consolidation.

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Theta and Gamma Power Increases and Alpha/Beta Power Decreases with Memory Load in an Attractor Network Model

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00029 ◽

2011 ◽

Vol 23 (10) ◽

pp. 3008-3020 ◽

Cited By ~ 88

Author(s):

Mikael Lundqvist ◽

Pawel Herman ◽

Anders Lansner

Keyword(s):

Working Memory ◽

Single Cell ◽

Network Model ◽

Memory Load ◽

Cell Activity ◽

Gamma Oscillations ◽

Attractor Network ◽

Beta Power ◽

Gamma Power ◽

Alpha Beta

Changes in oscillatory brain activity are strongly correlated with performance in cognitive tasks and modulations in specific frequency bands are associated with working memory tasks. Mesoscale network models allow the study of oscillations as an emergent feature of neuronal activity. Here we extend a previously developed attractor network model, shown to faithfully reproduce single-cell activity during retention and memory recall, with synaptic augmentation. This enables the network to function as a multi-item working memory by cyclic reactivation of up to six items. The reactivation happens at theta frequency, consistently with recent experimental findings, with increasing theta power for each additional item loaded in the network's memory. Furthermore, each memory reactivation is associated with gamma oscillations. Thus, single-cell spike trains as well as gamma oscillations in local groups are nested in the theta cycle. The network also exhibits an idling rhythm in the alpha/beta band associated with a noncoding global attractor. Put together, the resulting effect is increasing theta and gamma power and decreasing alpha/beta power with growing working memory load, rendering the network mechanisms involved a plausible explanation for this often reported behavior.

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Predictive Value of Slow and Fast EEG Oscillations for Methylphenidate Response in ADHD

Clinical EEG and Neuroscience ◽

10.1177/1550059419863206 ◽

2019 ◽

Vol 50 (5) ◽

pp. 332-338

Author(s):

Emel Sari Gokten ◽

Emine Elif Tulay ◽

Birsu Beser ◽

Mine Elagoz Yuksel ◽

Kemal Arikan ◽

...

Keyword(s):

Predictive Value ◽

Neurodevelopmental Disorder ◽

Quantitative Eeg ◽

Power Ratio ◽

Theta Power ◽

Hyperactivity Disorder ◽

Beta Power ◽

Binary Regression Analysis ◽

Gamma Power ◽

Fast Oscillations

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder and is characterized by symptoms of inattention and/or hyperactivity and impulsivity. In the current study, we obtained quantitative EEG (QEEG) recordings of 51 children aged between 6 and 12 years before the initiation of methylphenidate treatment. The relationship between changes in the scores of ADHD symptoms and initial QEEG features (power/power ratios values) were assessed. In addition, the children were classified as responder and nonresponder according to the ratio of their response to the medication (>25% improvement after medication). Logistic regression analyses were performed to analyze the accuracy of QEEG features for predicting responders. The findings indicate that patients with increased delta power at F8, theta power at Fz, F4, C3, Cz, T5, and gamma power at T6 and decreased beta powers at F8 and P3 showed more improvement in ADHD hyperactivity symptoms. In addition, increased delta/beta power ratio at F8 and theta/beta power ratio at F8, F3, Fz, F4, C3, Cz, P3, and T5 showed negative correlations with Conners’ score difference of hyperactivity as well. This means, those with greater theta/beta and delta/beta powers showed more improvement in hyperactivity following medication. Theta power at Cz and T5 and theta/beta power ratios at C3, Cz, and T5 have significantly classified responders and nonresponders according to the logistic binary regression analysis. The results show that slow and fast oscillations may have predictive value for treatment response in ADHD. Future studies should seek for more sensitive biomarkers.

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Spectral Properties of Induced and Evoked Gamma Oscillations in Human Early Visual Cortex to Moving and Stationary Stimuli

Journal of Neurophysiology ◽

10.1152/jn.91044.2008 ◽

2009 ◽

Vol 102 (2) ◽

pp. 1241-1253 ◽

Cited By ~ 85

Author(s):

J. B. Swettenham ◽

S. D. Muthukumaraswamy ◽

K. D. Singh

Keyword(s):

Visual Cortex ◽

Stimulus Presentation ◽

Gamma Oscillations ◽

Induced Response ◽

Stimulus Motion ◽

Time Frequency ◽

Beta Power ◽

Visual Areas ◽

Gamma Power ◽

Early Visual Cortex

In two experiments, magnetoencephalography (MEG) was used to investigate the effects of motion on gamma oscillations in human early visual cortex. When presented centrally, but not peripherally, stationary and moving gratings elicited several evoked and induced response components in early visual cortex. Time-frequency analysis revealed two nonphase locked gamma power increases—an initial, rapidly adapting response and one sustained throughout stimulus presentation and varying in frequency across observers from 28 to 64 Hz. Stimulus motion raised the sustained gamma oscillation frequency by a mean of ∼10 Hz. The largest motion-induced frequency increases were in those observers with the lowest gamma response frequencies for stationary stimuli, suggesting a possible saturation mechanism. Moderate gamma amplitude increases to moving versus stationary stimuli were also observed but were not correlated with the magnitude of the frequency increase. At the same site in visual cortex, sustained alpha/beta power reductions and an onset evoked response were observed, but these effects did not change significantly with the presence of motion and did not correlate with the magnitude of gamma power changes. These findings suggest that early visual areas encode moving and stationary percepts via activity at higher and lower gamma frequencies, respectively.

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Frontal eye field microstimulation induces task-dependent gamma oscillations in the lateral intraparietal area

Journal of Neurophysiology ◽

10.1152/jn.00323.2012 ◽

2012 ◽

Vol 108 (5) ◽

pp. 1392-1402 ◽

Cited By ~ 15

Author(s):

Elsie Premereur ◽

Wim Vanduffel ◽

Pieter R. Roelfsema ◽

Peter Janssen

Keyword(s):

Spatial Attention ◽

Field Potential ◽

Gamma Oscillations ◽

Oculomotor Control ◽

Saccade Target ◽

Frontal Eye Field ◽

Alpha Power ◽

Lateral Intraparietal Area ◽

Electrical Microstimulation ◽

Gamma Power

Macaque frontal eye fields (FEF) and the lateral intraparietal area (LIP) are high-level oculomotor control centers that have been implicated in the allocation of spatial attention. Electrical microstimulation of macaque FEF elicits functional magnetic resonance imaging (fMRI) activations in area LIP, but no study has yet investigated the effect of FEF microstimulation on LIP at the single-cell or local field potential (LFP) level. We recorded spiking and LFP activity in area LIP during weak, subthreshold microstimulation of the FEF in a delayed-saccade task. FEF microstimulation caused a highly time- and frequency-specific, task-dependent increase in gamma power in retinotopically corresponding sites in LIP: FEF microstimulation produced a significant increase in LIP gamma power when a saccade target appeared and remained present in the LIP receptive field (RF), whereas less specific increases in alpha power were evoked by FEF microstimulation for saccades directed away from the RF. Stimulating FEF with weak currents had no effect on LIP spike rates or on the gamma power during memory saccades or passive fixation. These results provide the first evidence for task-dependent modulations of LFPs in LIP caused by top-down stimulation of FEF. Since the allocation and disengagement of spatial attention in visual cortex have been associated with increases in gamma and alpha power, respectively, the effects of FEF microstimulation on LIP are consistent with the known effects of spatial attention.

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Reward-Associated Gamma Oscillations in Ventral Striatum Are Regionally Differentiated and Modulate Local Firing Activity

Journal of Neurophysiology ◽

10.1152/jn.00432.2009 ◽

2010 ◽

Vol 103 (3) ◽

pp. 1658-1672 ◽

Cited By ~ 50

Author(s):

Tobias Kalenscher ◽

Carien S. Lansink ◽

Jan V. Lankelma ◽

Cyriel M. A. Pennartz

Keyword(s):

Ventral Striatum ◽

Phase Locking ◽

Gamma Oscillations ◽

Brain Regions ◽

Reward Processing ◽

Temporal Organization ◽

Gamma Activity ◽

Neural Ensembles ◽

Gamma Range ◽

Gamma Power

Oscillations of local field potentials (LFPs) in the gamma range are found in many brain regions and are supposed to support the temporal organization of cognitive, perceptual, and motor functions. Even though gamma oscillations have also been observed in ventral striatum, one of the brain's most important structures for motivated behavior and reward processing, their specific function during ongoing behavior is unknown. Using a movable tetrode array, we recorded LFPs and activity of neural ensembles in the ventral striatum of rats performing a reward-collection task. Rats were running along a triangle track and in each round collected one of three different types of rewards. The gamma power of LFPs on subsets of tetrodes was modulated by reward-site visits, discriminated between reward types, between baitedness of reward locations and was different before versus after arrival at a reward site. Many single units in ventral striatum phase-locked their discharge pattern to the gamma oscillations of the LFPs. Phase-locking occurred more often in reward-related than in reward-unrelated neurons and LFPs. A substantial number of simultaneously recorded LFPs correlated poorly with each other in terms of gamma rhythmicity, indicating that the expression of gamma activity was heterogeneous and regionally differentiated. The orchestration of LFPs and single-unit activity by way of gamma rhythmicity sheds light on the functional architecture of the ventral striatum and the temporal coordination of ventral striatal activity for modulating downstream areas and regulating synaptic plasticity.

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The Consciousness State of Traditional Nidrâ Yoga/Modern Yoga Nidra: Phenomenological Characterization and Preliminary Insights from an EEG Study

International Journal of Yoga Therapy ◽

10.17761/2021-d-20-00014 ◽

2021 ◽

Author(s):

Andrea Zaccaro ◽

André Riehl ◽

Andrea Piarulli ◽

Gaspare Alfì ◽

Bruno Neri ◽

...

Keyword(s):

Rank Test ◽

Self Awareness ◽

Strong Concentration ◽

Yogic Practice ◽

Psychometric Data ◽

Beta Power ◽

Early Increase ◽

Gamma Power ◽

Psychophysiological Correlates ◽

Yoga Nidra

Nidrâ yoga is an ancient yogic practice capable of inducing altered states of consciousness characterized by deep relaxation, strong concentration, acute self-awareness, and joy. In modern contemplative neuroscience language, it is known by the name yoga nidra, and few studies have investigated its phenomenological and psychophysiological effects. Six healthy volunteers (four females aged 31–74) performed 12 yoga nidra sessions guided by an expert during a 6-day retreat. Each session consisted of 10 minutes in a resting state (baseline) followed by 2 hours of yoga nidra. Psychometric data regarding dissociative experiences (Clinician Administered Dissociative States Scale) and the state of consciousness (Phenomenology of Consciousness Inventory) were collected after baseline and yoga nidra, while high-density EEG was recorded during the entire session. During nidra sessions, no sleep hallmarks (i.e., K-complexes and sleep spindles) were detected by the EEG in any subject. Psychometric data we re analyzed using a Wilcoxon signed-rank test corrected with the false discovery rate approach for multiple comparisons. Compared to baseline, yoga nidra practice was related to: (1) increased dissociative effects (p = 0.022); (2) perception of being in an altered state of consciousness (p = 0.026); (3) alterations in perceived body image (p = 0.022); (4) increased “meaningfulness” attributed to the experience (p = 0.026); (5) reduced rational thinking (p = 0.029); and (6) reduced volitional thought control (p = 0.026). First-person experience is discussed in relation to descriptive EEG power spectral density analysis, which was performed in one subject because of severe EEG artifacts in the other recordings; that subject showed, compared to baseline: (1) early increase of alpha and beta power, followed by a progressive widespread reduction; (2) widespread early increase of theta power, followed by a progressive reduction; and (3) widespread increase of gamma power in the latest stages. The present preliminary results enrich the knowledge of yoga nidra, elucidating its phenomenology and suggesting some psychophysiological correlates that future studies may address.

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Cortical oscillations to measure anti-epileptic drug activity in clinical trials

10.21203/rs.3.rs-121959/v1 ◽

2021 ◽

Author(s):

Andrea Biondi ◽

Lorenzo Rocchi ◽

Viviana Santoro ◽

Gregory Beatch ◽

Pierre Rossini ◽

...

Keyword(s):

Clinical Trials ◽

Brain Activity ◽

Systematic Evaluation ◽

Alpha Power ◽

Brain Oscillations ◽

Cortical Oscillations ◽

Anti Epileptic Drug ◽

Beta Power ◽

Gamma Power

Abstract The frequency analysis of electroencephalographic (EEG) activity, either spontaneous or evoked by transcranial magnetic stimulation (TMS-EEG), is a powerful tool to investigate changes in brain activity and excitability following the administration of antiepileptic drugs (AEDs). However, a systematic evaluation of the effect of AEDs on spontaneous and TMS-induced brain oscillations has not yet been provided. We studied the effects of lamotrigine, levetiracetam, and of a novel potassium channel opener (XEN1101) on TMS-induced and spontaneous brain oscillations in a group of healthy volunteers. Levetiracetam suppressed TMS-induced theta, alpha and beta power, whereas lamotrigine increased TMS-induced alpha power. XEN1101 decreased TMS-induced delta, theta and beta power. Resting-state EEG showed a decrease of theta band power after lamotrigine intake. Levetiracetam increased theta, beta and gamma power, while XEN1101 produced an increase of delta, theta, beta and gamma power. Different AEDs induce specific patterns of power changes in spontaneous and TMS-induced brain oscillations. Spontaneous and TMS-induced cortical oscillations represent a powerful tool to characterize the effect of AEDs on in vivo brain activity. Spectral fingerprints of specific AEDs should be further investigated to provide robust and objective biomarkers of biological effect in human clinical trials.

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