scholarly journals The separation of auditory experience and the temporal structure of MEG recorded brain activity

2017 ◽  
Author(s):  
Chris Allen
Keyword(s):  
High Frequency ◽  
Temporal Dynamics ◽  
Brain Activity ◽  
Temporal Structure ◽  
Oscillatory Activity ◽  
Auditory Stimuli ◽  
Brain Oscillations ◽  
Successful Separation ◽  
Auditory Experience ◽  
Oscillatory Brain Activity

AbstractDo brain oscillations limit the temporal dynamics of experience? This pre-registered study used the separation of auditory stimuli to track perceptual experience and related this to oscillatory activity using magnetoencephalography. The rates at which auditory stimuli could be individuated matched the rates of oscillatory brain activity. Stimuli also entrained brain activity at the frequencies at which they were presented and a progression of high frequency gamma band events appeared to predict successful separation. These findings support a generalised function for brain oscillations, across frequency bands, in the alignment of activity to delineate representations.

scholarly journals Electrophysiological aftereffects of high-frequency transcranial random noise stimulation (hf-tRNS): an EEG investigation

2021 ◽  
Author(s):  
Filippo Ghin ◽  
Louise O’Hare ◽  
Andrea Pavan
Keyword(s):  
High Frequency ◽  
Discrimination Task ◽  
Temporal Dynamics ◽  
Random Noise ◽  
Decomposition Analysis ◽  
Oscillatory Activity ◽  
Motion Direction ◽  
Time Frequency ◽  
Direction Discrimination ◽  
Transcranial Random Noise Stimulation

AbstractThere is evidence that high-frequency transcranial random noise stimulation (hf-tRNS) is effective in improving behavioural performance in several visual tasks. However, so far there has been limited research into the spatial and temporal characteristics of hf-tRNS-induced facilitatory effects. In the present study, electroencephalogram (EEG) was used to investigate the spatial and temporal dynamics of cortical activity modulated by offline hf-tRNS on performance on a motion direction discrimination task. We used EEG to measure the amplitude of motion-related VEPs over the parieto-occipital cortex, as well as oscillatory power spectral density (PSD) at rest. A time–frequency decomposition analysis was also performed to investigate the shift in event-related spectral perturbation (ERSP) in response to the motion stimuli between the pre- and post-stimulation period. The results showed that the accuracy of the motion direction discrimination task was not modulated by offline hf-tRNS. Although the motion task was able to elicit motion-dependent VEP components (P1, N2, and P2), none of them showed any significant change between pre- and post-stimulation. We also found a time-dependent increase of the PSD in alpha and beta bands regardless of the stimulation protocol. Finally, time–frequency analysis showed a modulation of ERSP power in the hf-tRNS condition for gamma activity when compared to pre-stimulation periods and Sham stimulation. Overall, these results show that offline hf-tRNS may induce moderate aftereffects in brain oscillatory activity.

scholarly journals Physical exercise increases overall brain oscillatory activity but does not influence inhibitory control in young adults

2018 ◽  
Author(s):  
Luis F. Ciria ◽  
Pandelis Perakakis ◽  
Antonio Luque-Casado ◽  
Daniel Sanabria
Keyword(s):  
Physical Exercise ◽  
Inhibitory Control ◽  
Frequency Band ◽  
Brain Function ◽  
Acute Exercise ◽  
Brain Activity ◽  
Oscillatory Activity ◽  
Power Increase ◽  
Oscillatory Brain Activity ◽  
Exercise Induced

AbstractExtant evidence suggests that acute exercise triggers a tonic power increase in the alpha frequency band at frontal locations, which has been linked to benefits in cognitive function. However, recent literature has questioned such a selective effect on a particular frequency band, indicating a rather overall power increase across the entire frequency spectrum. Moreover, the nature of task-evoked oscillatory brain activity associated to inhibitory control after exercising, and the duration of the exercise effect, are not yet clear. Here, we investigate for the first time steady state oscillatory brain activity during and following an acute bout of aerobic exercise at two different exercise intensities (moderate-to-high and light), by means of a data-driven cluster-based approach to describe the spatio-temporal distribution of exercise-induced effects on brain function without prior assumptions on any frequency range or site of interest. We also assess the transient oscillatory brain activity elicited by stimulus presentation, as well as behavioural performance, in two inhibitory control (flanker) tasks, one performed after a short delay following the physical exercise and another completed after a rest period of 15’ post-exercise to explore the time course of exercise-induced changes on brain function and cognitive performance. The results show that oscillatory brain activity increases during exercise compared to the resting state, and that this increase is higher during the moderate-to-high intensity exercise with respect to the light intensity exercise. In addition, our results show that the global pattern of increased oscillatory brain activity is not specific to any concrete surface localization in slow frequencies, while in faster frequencies this effect is located in parieto-occipital sites. Notably, the exercise-induced increase in oscillatory brain activity disappears immediately after the end of the exercise bout. Neither transient (event-related) oscillatory activity, nor behavioral performance during the flanker tasks following exercise showed significant between-intensity differences. The present findings help elucidate the effect of physical exercise on oscillatory brain activity and challenge previous research suggesting improved inhibitory control following moderate-to-high acute exercise.

scholarly journals Bidirectional and context-dependent changes in theta and gamma oscillatory brain activity in noradrenergic cell-specific Hypocretin/Orexin receptor 1-KO mice

2017 ◽  
Author(s):  
Sha Li ◽  
Paul Franken ◽  
Anne Vassalli
Keyword(s):  
High Frequency ◽  
Slow Wave Sleep ◽  
Brain Activity ◽  
Orienting Response ◽  
Network Activity ◽  
Θ Rhythm ◽  
Narrow Bandwidth ◽  
Oscillatory Brain Activity ◽  
Na Release ◽  
Fine Tune

AbstractNoradrenaline (NA) and hypocretins/orexins (HCRT), and their receptors, dynamically modulate the circuits that configure behavioral states, and their associated oscillatory activities. Salient stimuli activate spiking of locus coeruleus noradrenergic (NALC) cells, inducing NA release and brain-wide noradrenergic signalling, thus resetting network activity, and mediating an orienting response. Hypothalamic HCRT neurons provide one of the densest input to NALC cells. To functionally address the HCRT-to-NA connection, we selectively disrupted the Hcrtr1 gene in NA neurons, and analyzed resulting (Hcrtr1Dbh-CKO) mice’, and their control littermates’ electrocortical response in several contexts of enhanced arousal. Under enforced wakefulness (EW), or after cage change (CC), Hcrtr1Dbh-CKO mice exhibited a weakened ability to lower infra-θ frequencies (1-7 Hz), and mount a robust, narrow-bandwidth, high-frequency θ rhythm (~8.5 Hz). A fast-γ (55-80 Hz) response, whose dynamics closely parallelled θ, also diminished, while β/slow-γ activity (15-45 Hz) increased. Furthermore, EW-associated locomotion was lower. Surprisingly, nestbuilding-associated wakefulness, inversely, featured enhanced θ and fast-γ activities. Thus HCRT-to-NA signalling may fine-tune arousal, up in alarming conditions, and down during self-motivated, goal-driven behaviors. Lastly, slow-wave-sleep following EW and CC, but not nestbuilding, was severely deficient in slow-δ waves (0.75-2.25 Hz), suggesting that HCRT-to-NA signalling regulates the slow-δ rebound characterizing sleep after stress-associated arousal.

scholarly journals Oscillations in the central brain ofDrosophilaare phase locked to attended visual features

2020 ◽  
Vol 117 (47) ◽  
pp. 29925-29936
Author(s):  
Martyna J. Grabowska ◽  
Rhiannon Jeans ◽  
James Steeves ◽  
Bruno van Swinderen
Keyword(s):  
Brain Activity ◽  
Visual Navigation ◽  
Central Complex ◽  
Oscillatory Activity ◽  
Visual Features ◽  
Attention Tasks ◽  
Temporal Features ◽  
Object Based ◽  
Oscillatory Brain Activity ◽  
Beta Frequency

Object-based attention describes the brain’s capacity to prioritize one set of stimuli while ignoring others. Human research suggests that the binding of diverse stimuli into one attended percept requires phase-locked oscillatory activity in the brain. Even insects display oscillatory brain activity during visual attention tasks, but it is unclear if neural oscillations in insects are selectively correlated to different features of attended objects. We addressed this question by recording local field potentials in theDrosophilacentral complex, a brain structure involved in visual navigation and decision making. We found that attention selectively increased the neural gain of visual features associated with attended objects and that attention could be redirected to unattended objects by activation of a reward circuit. Attention was associated with increased beta (20- to 30-Hz) oscillations that selectively locked onto temporal features of the attended visual objects. Our results suggest a conserved function for the beta frequency range in regulating selective attention to salient visual features.

scholarly journals EEG correlates of working memory performance in females

2017 ◽  
Author(s):  
Yuri G. Pavlov ◽  
Boris Kotchoubey
Keyword(s):  
Working Memory ◽  
Individual Differences ◽  
High Performance ◽  
Brain Activity ◽  
Memory Performance ◽  
Two Dimensions ◽  
Oscillatory Activity ◽  
Theta Power ◽  
Low Performance ◽  
Oscillatory Brain Activity

AbstractBackgroundThe study investigates oscillatory brain activity during working memory (WM) tasks. The tasks employed varied in two dimensions. First, they differed in complexity from average to highly demanding. Second, we used two types of tasks, which required either only retention of stimulus set or retention and manipulation of the content. We expected to reveal EEG correlates of temporary storage and central executive components of WM and to assess their contribution to individual differences.ResultsGenerally, as compared with the retention condition, manipulation of stimuli in WM was associated with distributed suppression of alpha1 activity and with the increase of the midline theta activity. Load and task dependent decrement of beta1 power was found during task performance. Beta2 power increased with the increasing WM load and did not significantly depend on the type of the task.At the level of individual differences, we found that the high performance (HP) group was characterized by higher alpha rhythm power. The HP group demonstrated task-related increment of theta power in the left anterior area and a gradual increase of theta power at midline area. In contrast, the low performance (LP) group exhibited a drop of theta power in the most challenging condition. HP group was also characterized by stronger desynchronization of beta1 rhythm over the left posterior area in the manipulation condition. In this condition, beta2 power increased in the HP group over anterior areas, but in the LP group over posterior areas.ConclusionsWM performance is accompanied by changes in EEG in a broad frequency range from theta to higher beta bands. The most pronounced differences in oscillatory activity between individuals with high and low WM performance can be observed in the most challenging WM task.

scholarly journals Neural oscillations while remembering traumatic memories in PTSD

2019 ◽  
Author(s):  
Inbal Reuveni ◽  
Noa Herz ◽  
Omer Bonne ◽  
Tuvia Peri ◽  
Shaul Schreiber ◽  
...  
Keyword(s):  
Traumatic Event ◽  
Brain Activity ◽  
Traumatic Experience ◽  
Oscillatory Activity ◽  
Traumatic Memory ◽  
Trauma Narratives ◽  
Frequency Bands ◽  
Traumatic Memories ◽  
Localization Analysis ◽  
Oscillatory Brain Activity

AbstractBackgroundIn posttraumatic stress disorder (PTSD), the traumatic event is often re-experienced through vivid sensory fragments of the traumatic experience. Though the sensory phenomenology of traumatic memories is well established, neural indications for this qualitative experience are lacking. The current study aimed at monitoring the oscillatory brain activity of PTSD patients during directed and imaginal exposure to the traumatic memory using magnetoencephalography (MEG), in a paradigm resembling exposure therapy.MethodsBrain activity of healthy trauma-exposed controls and PTSD participants was measured with MEG as they listened to individualized trauma narratives as well as to a neutral narrative and as they imagined the narrative in detail. Source localization analysis on varied frequency bands was conducted in order to map neural generators of altered oscillatory activity.ResultsPTSD patients exhibited increased power of high-frequency bands over visual areas and increased delta and theta power over auditory areas in response to trauma recollection compared to neutral recollection, while controls did not show such differential activation. PTSD participants also showed abnormal modulation of lower frequencies in the medial prefrontal cortex.ConclusionsElicitation of traumatic memories results in a distinct neural pattern in PTSD patients compared to healthy trauma-exposed individuals. Investigating the oscillatory neural dynamics of PTSD patients can help us better understand the processes underlying trauma re-experiencing.

Linking electrophysiological brain activity to neurological and psychiatric liability genes: Large-scale collaborative studies by the ENIGMA-EEG group.

2020 ◽  
Author(s):  
Dirk Smit
Keyword(s):  
Psychiatric Disorders ◽  
Brain Function ◽  
Large Scale ◽  
Genome Wide Association Study ◽  
Temporal Dynamics ◽  
Brain Activity ◽  
Meta Analysis ◽  
Genome Wide ◽  
Oscillatory Brain Activity ◽  
Eeg Features

The ENIGMA-EEG working group was established to enable large scale international collaborations among cohorts who investigate the genetics of brain function measured with electroencephalography (EEG). The collaboration resulted in the currently largest genome-wide association study of oscillatory brain activity in EEG recordings by meta-analyzing the results across five participating cohorts’ results. Our endeavor has resulted in the first genome-wide significant hits for oscillatory brain function, and significant genes that were previously associated with psychiatric disorders. Our results have provided insight into the influence that psychitaric liability genes have on the functioning brain. In this overview, we also highlight how we have tackled methodological issues surrounding genetic meta-analysis of EEG features, and identify possible sources of heterogeneity across cohorts, which could affect the results of our meta-analysis. We discuss the importance of harmonizing EEG signal processing, cleaning, and feature extraction. Finally, we explain our selection of EEG features to be investigated in our future studies, e.g. temporal dynamics of oscillations and the connectivity network based on synchronization of oscillations. We argue that these represent some of the most important characteristics of the functioning brain. We conclude that disentangling the genetics of EEG will elucidate effects that genes have on brain function, as well as pathways from genes to neurological and psychiatric disorders.

scholarly journals Binge drinking affects brain oscillations linked to motor inhibition and execution

2017 ◽  
Vol 31 (7) ◽  
pp. 873-882 ◽  
Author(s):  
Eduardo López-Caneda ◽  
Socorro Rodríguez Holguín ◽  
Ángeles Correas ◽  
Carina Carbia ◽  
Alberto González-Villar ◽  
...  
Keyword(s):  
Binge Drinking ◽  
Brain Activity ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Drinking Patterns ◽  
Motor Inhibition ◽  
Brain Oscillations ◽  
Oscillation Analysis ◽  
Related Potentials ◽  
Oscillatory Brain Activity

Introduction: Neurofunctional studies have shown that binge drinking patterns of alcohol consumption during adolescence and youth are associated with anomalies in brain functioning. Recent evidence suggests that event-related oscillations may be an appropriate index of neurofunctional damage associated with alcoholism. However, there is no study to date that has evaluated the effects of binge drinking on oscillatory brain responses related to task performance. The purpose of the present study was to examine brain oscillations linked to motor inhibition and execution in young binge drinkers (BDs) compared with age-matched controls. Methods: Electroencephalographic activity was recorded from 64 electrodes while 72 university students (36 controls and 36 BDs) performed a visual Go/NoGo task. Event-related oscillations along with the Go-P3 and NoGo-P3 event-related potential components were analysed. Results: While no significant differences between groups were observed regarding event-related potentials, event-related oscillation analysis showed that BDs displayed a lower oscillatory response than controls in delta and theta frequency ranges during Go and NoGo conditions. Conclusions: Findings are congruent with event-related oscillation studies showing reduced delta and/or theta oscillations in alcoholics during Go/NoGo tasks. Thus, BDs appear to show disruptions in neural oscillations linked to motor inhibition and execution similar to those observed in alcohol-dependent subjects. Finally, these results are the first to evidence that oscillatory brain activity may be a sensitive indicator of underlying brain anomalies in young BDs, which could complement standard event-related potential measures.

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