Resting-state Oscillatory Activity Research Articles

Degree of multilingual engagement modulates resting state oscillatory activity across the lifespan

Multilingualism has been demonstrated to lead to a more favorable trajectory of neurocognitive aging, yet our understanding of its effect on neurocognition across the lifespan remains limited. We collected resting state EEG recordings from a sample of multilingual individuals across a wide age range. Additionally, we obtained data on participant multilingual language use patterns alongside other known lifestyle enrichment factors. Language experience was operationalized via a modified multilingual diversity (MLD) score. Generalized additive modeling was employed to examine the effects and interactions of age and MLD on resting state oscillatory power and coherence. The data suggest an independent modulatory effect of individualized multilingual engagement on age-related differences in whole brain resting state power across alpha and theta bands, and an interaction between age and MLD on resting state coherence in alpha, theta, and low beta. These results provide evidence of multilingual engagement as an independent correlational factor related to differences in resting state EEG power, consistent with the claim that multilingualism can serve as a protective factor in neurocognitive aging.

Aberrant oscillatory activity in neurofibromatosis type 1: an EEG study of resting state and working memory

BackgroundNeurofibromatosis type 1 (NF1) is a genetic neurodevelopmental disorder commonly associated with impaired cognitive function. Despite the well-explored functional roles of neural oscillations in neurotypical populations, only a limited number of studies have investigated oscillatory activity in the NF1 population.MethodsWe compared oscillatory spectral power and theta phase coherence in a paediatric sample with NF1 (N = 16; mean age: 13.03 years; female: n = 7) to an age/sex-matched typically developing control group (N = 16; mean age: 13.34 years; female: n = 7) using electroencephalography measured during rest and during working memory task performance.ResultsRelative to typically developing children, the NF1 group displayed higher resting state slow wave power and a lower peak alpha frequency. Moreover, higher theta power and frontoparietal theta phase coherence were observed in the NF1 group during working memory task performance, but these differences disappeared when controlling for baseline (resting state) activity.ConclusionsOverall, results suggest that NF1 is characterised by aberrant resting state oscillatory activity that may contribute towards the cognitive impairments experienced in this population.Trial registrationClinicalTrials.gov, NCT03310996 (first posted: October 16, 2017).

Atypical cortical networks in children at high-genetic risk of psychiatric and neurodevelopmental disorders

Although many genetic risk factors for psychiatric and neurodevelopmental disorders have been identified, the neurobiological route from genetic risk to neuropsychiatric outcome remains unclear. 22q11.2 deletion syndrome (22q11.2DS) is a copy number variant (CNV) syndrome associated with high rates of neurodevelopmental and psychiatric disorders including autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) and schizophrenia. Alterations in neural integration and cortical connectivity have been linked to the spectrum of neuropsychiatric disorders seen in 22q11.2DS and may be a mechanism by which the CNV acts to increase risk. In this study, magnetoencephalography (MEG) was used to investigate electrophysiological markers of local and global network function in 34 children with 22q11.2DS and 25 controls aged 10–17 years old. Resting-state oscillatory activity and functional connectivity across six frequency bands were compared between groups. Regression analyses were used to explore the relationships between these measures, neurodevelopmental symptoms and IQ. Children with 22q11.2DS had altered network activity and connectivity in high and low frequency bands, reflecting modified local and long-range cortical circuitry. Alpha and theta band connectivity were negatively associated with ASD symptoms while frontal high frequency (gamma band) activity was positively associated with ASD symptoms. Alpha band activity was positively associated with cognitive ability. These findings suggest that haploinsufficiency at the 22q11.2 locus impacts short and long-range cortical circuits, which could be a mechanism underlying neurodevelopmental and psychiatric vulnerability in this high-risk group.

P-120 EEG biomarkers based on task-related and resting state oscillatory activity for classifying sight restored individuals

P-120 EEG biomarkers based on task-related and resting state oscillatory activity for classifying sight restored individuals

Higher Peripheral Inflammation Is Associated With Lower Orbitofrontal Gamma Power in Chronic Tinnitus.

Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom, for which the underlying pathology has not yet been fully understood. It is associated with neurophysiological alterations in the central nervous system and chronic stress, which can be related with a disinhibition of the inflammatory system. We here investigated the association between resting-state oscillatory activity assessed with Magnetoencephalography (MEG), and peripheral inflammation assessed by C-reactive protein (CRP) in a group of patients with chronic tinnitus (N = 21, nine males, mean age: 40.6 ± 14.6 years). Additionally, CRP was assessed in an age- and sex-matched healthy control group (N = 21, nine males, mean age: 40.9 ± 15.2 years). No MEG data was available for the control group. We found a significant negative correlation between CRP and gamma power in the orbitofrontal cortex in tinnitus patients (p < 0.001), pointing to a deactivation of the orbitofrontal cortex when CRP was high. No significant clusters were found for other frequency bands. Moreover, CRP levels were significantly higher in the tinnitus group than in the healthy controls (p = 0.045). Our results can be interpreted based on findings from previous studies having disclosed the orbitofrontal cortex as part of the tinnitus distress network. We suggest that higher CRP levels and the associated deactivation of the orbitofrontal cortex in chronic tinnitus patients is maintaining the tinnitus percept through disinhibition of the auditory cortex and attentional or emotional top-down processes. Although the direction of the association (i.e., causation) between CRP levels and orbitofrontal gamma power in chronic tinnitus is not yet known, inflammation reducing interventions are promising candidates when developing treatments for tinnitus patients. Overall, our study highlights the importance of considering immune-brain communication in tinnitus research.

Developmental trajectory of MEG resting-state oscillatory activity in children and adolescents: a longitudinal reliability study.

Neural oscillations may be sensitive to aspects of brain maturation such as myelination and synaptic density changes. Better characterization of developmental trajectories and reliability is necessary for understanding typical and atypical neurodevelopment. Here, we examined reliability in 110 typically developing children and adolescents (aged 9-17years) across 2.25years. From 10 min of magnetoencephalography resting-state data, normalized source spectral power and intraclass correlation coefficients were calculated. We found sex-specific differences in global normalized power, with males showing age-related decreases in delta and theta, along with age-related increases in beta and gamma. Females had fewer significant age-related changes. Structural magnetic resonance imaging revealed that males had more total gray, subcortical gray, and cortical white matter volume. There were significant age-related changes in total gray matter volume with sex-specific and frequency-specific correlations to normalized power. In males, increased total gray matter volume correlated with increased theta and alpha, along with decreased gamma. Split-half reliability was excellent in all frequency bands and source regions. Test-retest reliability ranged from good (alpha) to fair (theta) to poor (remaining bands). While resting-state neural oscillations can have fingerprint-like quality in adults, we show here that neural oscillations continue to evolve in children and adolescents due to brain maturation and neurodevelopmental change.

The impact of gliomas on resting-state oscillatory activity and connectivity: A magnetoencephalography study

Gliomas disturb brain functions, contributing to abnormal neuronal activity and connectivity changes that can be effectively investigated using magnetoencephalography (MEG). In this work, we used MEG to evaluate frequency-specific alterations of brain activity and functional connectivity in glioma patients. Two consecutive 5-min sessions of eyes-closed resting-state brain activity were recorded from ten glioma patients and ten age-matched healthy subjects. Modulations of power and functional connectivity, within the patient group and between patients and the healthy control group, were assessed in terms of the Neural Activity Index and the Multivariate Interaction Measure, respectively. These quantities were calculated in individualized frequency bands (delta, theta, lower alpha, upper alpha and beta) to account for changes in spectral peaks in patients.We report a decrease in power in tumor and peri-tumor regions in the upper-alpha and beta bands with respect to the rest of the brain, paired to a decrease in lower and upper-alpha band functional connectivity of the tumor and peri-tumor regions. In comparison with healthy subjects, we observe a global enhancement in power in lower-alpha in patients.Overall, our study shows that glioma infiltration can widely influence brain local and long-range synchrony in an individualized frequency-specific manner.

Impact of Gliomas on Resting-State Oscillatory Activity and Connectivity: A Magnetoencephalography Study

Impact of Gliomas on Resting-State Oscillatory Activity and Connectivity: A Magnetoencephalography Study

Resolving the Connectome, Spectrally-Specific Functional Connectivity Networks and Their Distinct Contributions to Behavior.

The resting human brain exhibits spontaneous patterns of activity that reflect features of the underlying neural substrate. Examination of interareal coupling of resting-state oscillatory activity has revealed that the brain’s resting activity is composed of functional networks, whose topographies differ depending on oscillatory frequency, suggesting a role for carrier frequency as a means of creating multiplexed, or functionally segregated, communication channels between brain areas. Using canonical correlation analysis (CCA), we examined spectrally resolved resting-state connectivity patterns derived from magnetoencephalography (MEG) recordings to determine the relationship between connectivity intrinsic to different frequency channels and a battery of over a hundred behavioral and demographic indicators, in a group of 89 young healthy participants. We demonstrate that each of the classical frequency bands in the range 1–40 Hz (δ, θ, α, β, and γ) delineates a subnetwork that is behaviorally relevant, spatially distinct, and whose expression is either negatively or positively predictive of individual traits, with the strongest link in the α-band being negative and networks oscillating at different frequencies, such as θ, β, and γ carrying positive function.

The noise-resilient brain: Resting-state oscillatory activity predicts words-in-noise recognition

The role of neuronal oscillations in the processing of speech has recently come to prominence. Since resting-state (RS) brain activity has been shown to predict both task-related brain activation and behavioural performance, we set out to establish whether inter-individual differences in spectrally-resolved RS-MEG power are associated with variations in words-in-noise recognition in a sample of 88 participants made available by the Human Connectome Project. Positive associations with resilience to noise were observed with power in the range 21 and 29 Hz in a number of areas along the left temporal gyrus and temporo-parietal association areas peaking in left posterior superior temporal gyrus (pSTG). Significant associations were also found in the right posterior superior temporal gyrus in the frequency range 30–40 Hz. We propose that individual differences in words-in-noise performance are related to baseline excitability levels of the neural substrates of phonological processing.

Posterior resting state EEG asymmetries are associated with hedonic valuation of food

Research on the hedonic value of food has been important in understanding the motivational and emotional correlates of normal and abnormal eating behaviour. The aim of the present study was to explore associations between hemispheric asymmetries recorded during resting state electroencephalogram (EEG) and hedonic valuation of food. Healthy adult volunteers were recruited and four minutes of resting state EEG were recorded from the scalp. Hedonic food valuation and reward sensitivity were assessed with the hedonic attitude to food and behavioural activation scale. Results showed that parieto-occipital resting state EEG asymmetries in the alpha (8–12Hz) and beta (13–30Hz) frequency range correlate with the hedonic valuation of food. Our findings suggest that self-reported sensory-related attitude towards food is associated with interhemispheric asymmetries in resting state oscillatory activity. Our findings contribute to understanding the electrophysiological correlates of hedonic valuation, and may provide an opportunity to modulate the cortical imbalance by using non-invasive brain stimulation methods to change food consumption.

Pharmacological modulation of pulvinar resting-state regional oscillations and network dynamics in major depression

The pulvinar, the largest thalamus nucleus, has rich anatomical connections with several different cortical and subcortical regions suggesting its important involvement in high-level cognitive and emotional functions. Unfortunately, pulvinar dysfunction in psychiatric disorders particularly major depression disorder has not been thoroughly examined to date. In this study we explored the alterations in the baseline regional and network activities of the pulvinar in MDD by applying spectral analysis of resting-state oscillatory activity, functional connectivity and directed (effective) connectivity on resting-state fMRI data acquired from 20 healthy controls and 19 participants with MDD. Furthermore, we tested how pharmacological treatment with duloxetine can modulate the measured local and network variables in ten participants who completed treatment. Our results revealed a frequency-band dependent modulation of power spectrum characteristics of pulvinar regional oscillatory activity. At the network level, we found MDD is associated with aberrant causal interactions between pulvinar and several systems including default-mode and posterior insular networks. It was also shown that duloxetine treatment can correct or overcompensate the pathologic network behavior of the pulvinar. In conclusion, we suggest that pulvinar regional baseline oscillatory activity and its resting-state network dynamics are compromised in MDD and can be modulated therapeutically by pharmacological treatment.

Source space estimation of oscillatory power and brain connectivity in tinnitus.

Tinnitus is the perception of an internally generated sound that is postulated to emerge as a result of structural and functional changes in the brain. However, the precise pathophysiology of tinnitus remains unknown. Llinas’ thalamocortical dysrhythmia model suggests that neural deafferentation due to hearing loss causes a dysregulation of coherent activity between thalamus and auditory cortex. This leads to a pathological coupling of theta and gamma oscillatory activity in the resting state, localised to the auditory cortex where normally alpha oscillations should occur. Numerous studies also suggest that tinnitus perception relies on the interplay between auditory and non-auditory brain areas. According to the Global Brain Model, a network of global fronto—parietal—cingulate areas is important in the generation and maintenance of the conscious perception of tinnitus. Thus, the distress experienced by many individuals with tinnitus is related to the top—down influence of this global network on auditory areas. In this magnetoencephalographic study, we compare resting-state oscillatory activity of tinnitus participants and normal-hearing controls to examine effects on spectral power as well as functional and effective connectivity. The analysis is based on beamformer source projection and an atlas-based region-of-interest approach. We find increased functional connectivity within the auditory cortices in the alpha band. A significant increase is also found for the effective connectivity from a global brain network to the auditory cortices in the alpha and beta bands. We do not find evidence of effects on spectral power. Overall, our results provide only limited support for the thalamocortical dysrhythmia and Global Brain models of tinnitus.

Neural Activations during Visual Sequence Learning Leave a Trace in Post-Training Spontaneous EEG

Recent EEG studies have shown that implicit learning involving specific cortical circuits results in an enduring local trace manifested as local changes in spectral power. Here we used a well characterized visual sequence learning task and high density-(hd-)EEG recording to determine whether also declarative learning leaves a post-task, local change in the resting state oscillatory activity in the areas involved in the learning process. Thus, we recorded hd-EEG in normal subjects before, during and after the acquisition of the order of a fixed spatial target sequence (VSEQ) and during the presentation of targets in random order (VRAN). We first determined the temporal evolution of spectral changes during VSEQ and compared it to VRAN. We found significant differences in the alpha and theta bands in three main scalp regions, a right occipito-parietal (ROP), an anterior-frontal (AFr), and a right frontal (RFr) area. The changes in frontal theta power during VSEQ were positively correlated with the learning rate. Further, post-learning EEG recordings during resting state revealed a significant increase in alpha power in ROP relative to a pre-learning baseline. We conclude that declarative learning is associated with alpha and theta changes in frontal and posterior regions that occur during the task, and with an increase of alpha power in the occipito-parietal region after the task. These post-task changes may represent a trace of learning and a hallmark of use-dependent plasticity.

Resting-State Oscillatory Activity in Autism Spectrum Disorders

Neural oscillatory anomalies in autism spectrum disorders (ASD) suggest an excitatory/inhibitory imbalance; however, the nature and clinical relevance of these anomalies are unclear. Whole-cortex magnetoencephalography data were collected while 50 children (27 with ASD, 23 controls) underwent an eyes-closed resting-state exam. A Fast Fourier Transform was applied and oscillatory activity examined from 1 to 120Hz at 15 regional sources. Associations between oscillatory anomalies and symptom severity were probed. Children with ASD exhibited regionally specific elevations in delta (1-4Hz), theta (4-8Hz), alpha (8-12Hz), and high frequency (20-120Hz) power, supporting an imbalance of neural excitation/inhibition as a neurobiological feature of ASD. Increased temporal and parietal alpha power was associated with greater symptom severity and thus is of particular interest.

P3.119 Characteristics of resting-state oscillatory activity in the basal ganglia-cortical loop in the 6-OHDA-lesioned rat models of Parkinson's disease

P3.119 Characteristics of resting-state oscillatory activity in the basal ganglia-cortical loop in the 6-OHDA-lesioned rat models of Parkinson's disease

Cholinergic modulation of MEG resting-state oscillatory activity in Parkinson’s disease related dementia

EEG and MEG studies in Parkinson's disease (PD) related dementia (PDD) have shown a slowing of resting-state, oscillatory activity compared to non demented PD. Aim of the present MEG study was to determine whether treatment with the cholinesterase inhibitor rivastigmine would reverse this slowing of resting-state activity in PDD patients. In eight PDD patients, whole head MEG was recorded in a resting-state condition before and after treatment with rivastigmine. Relative spectral power was calculated in the delta, theta, alpha, beta and gamma frequency bands in fronto-central, parieto-occipital and temporal regions. After treatment with rivastigmine, PDD patients demonstrated an increase in relative power in the alpha range in parieto-occipital and temporal regions together with a diffuse increase in beta power. Furthermore, a decrease of delta power in fronto-central and parieto-occipital regions was found. Treatment with the cholinesterase inhibitor rivastigmine at least partly counteracts the slowing of resting-state brain activity that is known to occur in PD related dementia. Our observations emphasize the prominent role of degeneration of the cholinergic system in the pathophysiology of dementia in PD. In the future, MEG might contribute to the selection of PD patients who may optimally benefit from cholinergic treatment.

TUO08 Cholinergic modulation of MEG resting state oscillatory activity in Parkinson's disease related dementia

TUO08 Cholinergic modulation of MEG resting state oscillatory activity in Parkinson's disease related dementia