scholarly journals Individual alpha peak frequency is slower in schizophrenia and related to deficits in visual perception and cognition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ian S. Ramsay ◽  
Peter Lynn ◽  
Brandon Schermitzler ◽  
Scott Sponheim
Keyword(s):  
Visual Perception ◽  
Visual Attention ◽  
Resting State ◽  
Peak Frequency ◽  
Attention Task ◽  
Eyes Closed ◽  
Global Cognition ◽  
The Relationship ◽  
The Brain ◽  
Alpha Peak

AbstractThe brain at rest generates cycles of electrical activity that have been shown to be abnormal in people with schizophrenia. The alpha rhythm (~ 10 Hz) is the dominant resting state electrical cycle and each person has a propensity toward a particular frequency of oscillation for this rhythm. This individual alpha peak frequency (IAPF) is hypothesized to be central to visual perceptual processes and may have downstream influences on cognitive functions such as attention, working memory, or problem solving. In the current study we sought to determine whether IAPF was slower in schizophrenia, and whether lower IAPF predicted deficits in visual perception and cognition that are often observed in schizophrenia. Eyes-closed resting state EEG activity, visual attention, and global cognitive functioning were assessed in individuals with schizophrenia (N = 104) and a group of healthy controls (N = 101). Compared to controls, the schizophrenia group showed slower IAPF and was associated with poorer discrimination of visual targets and nontargets on a computerized attention task, as well as impaired global cognition measured using neuropsychological tests across groups. Notably, disruptions in visual attention fully mediated the relationship between IAPF and global cognition across groups. The current findings demonstrate that slower alpha oscillatory cycling accounts for global cognitive deficits in schizophrenia by way of impairments in perceptual discrimination measured during a visual attention task.

scholarly journals Resting-state MEG measurement of functional activation as a biomarker for cognitive decline in MS

2018 ◽  
Vol 25 (14) ◽  
pp. 1896-1906 ◽  
Author(s):  
Deborah N Schoonhoven ◽  
Matteo Fraschini ◽  
Prejaas Tewarie ◽  
Bernard MJ Uitdehaag ◽  
Anand JC Eijlers ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Resting State ◽  
Brain Function ◽  
Peak Frequency ◽  
Cognitively Impaired ◽  
Clinical Neurology ◽  
Linear Regression Models ◽  
Eyes Closed ◽  
Gender And Education ◽  
Cognitive Disturbances

Background: Neurophysiological measures of brain function, such as magnetoencephalography (MEG), are widely used in clinical neurology and have strong relations with cognitive impairment and dementia but are still underdeveloped in multiple sclerosis (MS). Objectives: To demonstrate the value of clinically applicable MEG-measures in evaluating cognitive impairment in MS. Methods: In eyes-closed resting-state, MEG data of 83 MS patients and 34 healthy controls (HCs) peak frequencies and relative power of six canonical frequency bands for 78 cortical and 10 deep gray matter (DGM) areas were calculated. Linear regression models, correcting for age, gender, and education, assessed the relation between cognitive performance and MEG biomarkers. Results: Increased alpha1 and theta power was strongly associated with impaired cognition in patients, which differed between cognitively impaired (CI) patients and HCs in bilateral parietotemporal cortices. CI patients had a lower peak frequency than HCs. Oscillatory slowing was also widespread in the DGM, most pronounced in the thalamus. Conclusion: There is a clinically relevant slowing of neuronal activity in MS patients in parietotemporal cortical areas and the thalamus, strongly related to cognitive impairment. These measures hold promise for the application of resting-state MEG as a biomarker for cognitive disturbances in MS in a clinical setting.

scholarly journals Author Correction: Individual alpha peak frequency is slower in schizophrenia and related to deficits in visual perception and cognition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ian S. Ramsay ◽  
Peter A. Lynn ◽  
Brandon Schermitzler ◽  
Scott R. Sponheim
Keyword(s):  
Visual Perception ◽  
Peak Frequency ◽  
Alpha Peak

scholarly journals Shifts in broadband power and alpha peak frequency observed during long-term isolation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jan Weber ◽  
Timo Klein ◽  
Vera Abeln
Keyword(s):  
Sensory Deprivation ◽  
Peak Frequency ◽  
Neuronal Population ◽  
Confined Space ◽  
Eyes Closed ◽  
Eyes Open ◽  
Eeg Recordings ◽  
Induced Changes ◽  
Alpha Peak

Abstract Prolonged periods of social isolation and spatial confinement do not only represent an issue that needs to be faced by a few astronauts during space missions, but can affect all of us as recently shown during pandemic situations. The fundamental question, how the brain adapts to periods of sensory deprivation and re-adapts to normality, has only received little attention. Here, we use eyes closed and eyes open resting-state electroencephalographic (EEG) recordings to investigate how neural activity is altered during 120 days of isolation in a spatially confined, space-analogue environment. After disentangling oscillatory patterns from 1/f activity, we show that isolation leads to a reduction in broadband power and a flattening of the 1/f spectral slope. Beyond that, we observed a reduction in alpha peak frequency during isolation, but did not find strong evidence for isolation-induced changes that are of oscillatory nature. Critically, all effects reversed upon release from isolation. These findings suggest that isolation and concomitant sensory deprivation lead to an enhanced cortical deactivation which might be explained by a reduction in the mean neuronal population firing rate.

Assessing the Retest Reliability of Prefrontal EEG Markers of Brain Rhythm Slowing in the Eyes-Closed Resting State

2020 ◽  
Vol 51 (5) ◽  
pp. 348-356 ◽  
Author(s):  
Jungmi Choi ◽  
Eunjo Lim ◽  
Min-Goo Park ◽  
Wonseok Cha
Keyword(s):  
Resting State ◽  
Brain Aging ◽  
Low Cost ◽  
Peak Frequency ◽  
Brain Regions ◽  
Median Frequency ◽  
Brain Functions ◽  
Eyes Closed ◽  
Alpha Beta ◽  
Prefrontal Lobe

Objective. We examined whether prefrontal lobe EEG markers of slower brain rhythms, which are correlated with functional brain aging, can reliably reflect those of other brain lobes, as measured by a multichannel device. Methods. EEG measurements were taken of 112 healthy individuals aged 20 to 69 years in the eyes-closed resting state. A 5-minute measurement was taken at 8 regions (Fp1, Fp2, F3, F4, T3, T4, O1, O2). Indices (median frequency [MDF], peak frequency [PF]) that quantitatively reflect the characteristics of EEG slowing, and traditional commonly used spectral indices (absolute powers as delta, theta, alpha, beta, and relative power as alpha-to-theta ratio [ATR]), were extracted from the EEG signals. For these indices, the differences between the prefrontal lobe and other areas were analyzed and the test-retest reproducibility was investigated. Results. The EEG slowing indicators showed high conformity over all brain lobes and stable reproducibility. On the other hand, the typical EEG spectral indicators delta, theta, alpha, beta, and ATR differed between brain regions. Conclusion. It was found that EEG slowing markers, which were used for assessing the aging or degeneration of brain functions, could be reliably extracted from a prefrontal EEG alone. Significance. These findings suggest that EEG prefrontal markers may reflect markers of other brain regions when a multi-channel device is used. Thus, this method may constitute a low-cost, wearable, wireless, easily accessible, and noninvasive tool for neurological assessment that could be used in the early detection of cognitive decline and in the prevention of dementia.

scholarly journals Resting-state EEG power and connectivity are associated with alpha peak frequency slowing in healthy aging

2018 ◽  
Vol 71 ◽  
pp. 149-155 ◽  
Author(s):  
Brian Scally ◽  
Melanie Rose Burke ◽  
David Bunce ◽  
Jean-Francois Delvenne
Keyword(s):  
Resting State ◽  
Healthy Aging ◽  
Peak Frequency ◽  
Eeg Power ◽  
Alpha Peak

scholarly journals Alpha peak frequency is linked to episodic memory impairment in pathological aging

2021 ◽  
Author(s):  
Delphine Puttaert ◽  
Vincent Wens ◽  
Patrick Fery ◽  
Antonin Rovai ◽  
Nicola Trotta ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Resting State ◽  
Early Stage ◽  
Brain Activity ◽  
Peak Frequency ◽  
Short Term ◽  
Slowing Down ◽  
Pathological Aging ◽  
18Fdg Pet ◽  
Alpha Peak

The Free and Cued Selective Reminding Test (FCSRT) is a largely validated neuropsychological test for the identification of amnestic syndrome from the early stage of Alzheimers disease (AD). Previous electrophysiological data suggested a slowing down of the alpha rhythm in the AD-continuum as well as a key role of this rhythmic brain activity for episodic memory processes. This study therefore investigates the link between alpha brain activity and alterations in episodic memory as assessed by the FCSRT. For that purpose, 37 patients with altered FCSRT performance underwent a comprehensive neuropsychological assessment, supplemented by 18F-fluorodeoxyglucose positron emission tomography/structural magnetic resonance imaging (18FDG-PET/MR), and 10 minutes of resting-state magnetoencephalography (MEG). The individual alpha peak frequency (APF) in MEG resting-state data was positively correlated with patients encoding efficiency as well as with the efficacy of semantic cues in facilitating patients retrieval of previous stored word. The APF also correlated positively with patients hippocampal volume and their regional glucose consumption in the posterior cingulate cortex. Overall, this study demonstrates that alterations in the ability to learn and store new information for a relatively short-term period are related to a slowing down of alpha rhythmic activity, possibly due to altered interactions in the extended mnemonic system. As such, a decreased APF may be considered as an electrophysiological correlate of short-term episodic memory dysfunction accompanying pathological aging.

scholarly journals Individual alpha peak frequency predicts 10 Hz flicker effects on selective attention

2017 ◽  
Author(s):  
Rasa Gulbinaite ◽  
Tara van Viegen ◽  
Martijn Wieling ◽  
Michael X Cohen ◽  
Rufin VanRullen
Keyword(s):  
Selective Attention ◽  
Task Performance ◽  
Visual Stimulation ◽  
Peak Frequency ◽  
Alpha Band ◽  
Attention Task ◽  
Stimulus Processing ◽  
Brain Rhythms ◽  
Attention Demands ◽  
Alpha Peak

ABSTRACTRhythmic visual stimulation (“flicker”) is primarily used to “tag” processing of low-level visual and high-level cognitive phenomena. However, preliminary evidence suggests that flicker may also entrain endogenous brain oscillations, thereby modulating cognitive processes supported by those brain rhythms. Here we tested the interaction between 10 Hz flicker and endogenous alpha-band (~10 Hz) oscillations during a selective visuospatial attention task. We recorded EEG from human participants (both genders) while they performed a modified Eriksen flanker task in which distractors and targets flickered within (10 Hz) or outside (7.5 or 15 Hz) the alpha band. By using a combination of EEG source separation, time-frequency, and single-trial linear mixed effects modeling, we demonstrate that 10 Hz flicker interfered with stimulus processing more on incongruent than congruent trials (high vs. low selective attention demands). Crucially, the effect of 10 Hz flicker on task performance was predicted by the distance between 10 Hz and individual alpha peak frequency (estimated during the task). Finally, the flicker effect on task performance was more strongly predicted by EEG flicker responses during stimulus processing than during preparation for the upcoming stimulus, suggesting that 10 Hz flicker interfered more with reactive than proactive selective attention. These findings are consistent with our hypothesis that visual flicker entrained endogenous alpha-band networks, which in turn impaired task performance. Our findings also provide novel evidence for frequency-dependent exogenous modulation of cognition that is determined by the correspondence between the exogenous flicker frequency and the endogenous brain rhythms.SignificanceHere we provide novel evidence that the interaction between exogenous rhythmic visual stimulation and endogenous brain rhythms can have frequency-specific behavioral effects. We show that alpha-band (10 Hz) flicker impairs stimulus processing in a selective attention task when the stimulus flicker rate matches individual alpha peak frequency. The effect of sensory flicker on task performance was stronger when selective attention demands were high, and was stronger during stimulus processing and response selection compared to the pre-stimulus anticipatory period. These findings provide novel evidence that frequency-specific sensory flicker affects online attentional processing, and also demonstrate that the correspondence between exogenous and endogenous rhythms is an overlooked prerequisite when testing for frequency-specific cognitive effects of flicker.

Analysis of a Signal Transmission in a Pair of Izhikevich Coupled Neurons

2020 ◽  
Vol 15 (04) ◽  
pp. 195-206
Author(s):  
David. H. Margarit ◽  
Marcela V. Reale ◽  
Ariel F. Scagliotti
Keyword(s):  
White Noise ◽  
Resting State ◽  
Signal Transmission ◽  
Electrical Potential ◽  
Signal Amplitude ◽  
Receptor Neuron ◽  
Neuron Models ◽  
The Relationship ◽  
The Brain ◽  
Izhikevich Model

Individual neuron models give a comprehensive explanation of the behavior of the electrical potential of cell membranes. These models were and are a source of constant analysis to understand the functioning of, mainly, the complexity of the brain. In this work, using the Izhikevich model, we propose, analyze and characterize the transmission of a signal between two neurons unidirectionally coupled. Two possible states were characterized (sub-threshold and over-threshold) depending on the values of the signal amplitude, as well also the relationship between the transmitted and received signal taking into account the coupling. Furthermore, the activation of the emitting neuron (its transition from a resting state to spiking state) and the transmission to the receptor neuron were analyzed by adding white noise to the system.

Functional connectivity and microstructural changes of the brain in primary Sjögren syndrome: the relationship with depression

2020 ◽  
Vol 61 (12) ◽  
pp. 1684-1694
Author(s):  
Artemis Andrianopoulou ◽  
Anastasia K Zikou ◽  
Loukas G Astrakas ◽  
Nafsika Gerolymatou ◽  
Vasileios Xydis ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Connectivity ◽  
Resting State ◽  
Pulse Sequence ◽  
Sjogren Syndrome ◽  
White Matter Tracts ◽  
Microstructural Changes ◽  
Primary Sjögren Syndrome ◽  
The Relationship ◽  
The Brain

Background Fatigue and depression are among the most common manifestations of primary Sjögren syndrome (pSS), but information is lacking on the relationship with brain function and microstructural changes. Purpose To investigate microstructural changes and brain connectivity in pSS, and to evaluate their relationship with fatigue and depression. Material and Methods The study included 29 patients with pSS (mean age 61.2 ± 12.1 years; disease duration 10.5 ± 5.9 years) and 28 controls (mean age 58.4 ± 9.2 years). All the patients completed the Beck’s depression and Fatigue Assessment Scale questionnaires. The imaging protocol consisted of: (i) standard magnetic resonance imaging (MRI) pulse sequences (FLAIR, 3D T1W); (ii) a diffusion tensor imaging pulse sequence; and (iii) a resting state functional MRI pulse sequence. Resting state brain networks and maps of diffusion metrics were calculated and compared between patients and controls. Results Compared with the controls, the patients with pSS and depression showed increased axial, radial, and mean diffusivity and decreased fractional anisotropy; those without depression showed decreased axial diffusivity in major white matter tracts (superior longitudinal fasciculus, inferior longitudinal fasciculus, corticospinal tract, anterior thalamic radiation, inferior fronto-occipital fasciculus, cingulum, uncinate fasciculus, and forceps minor-major). Decreased brain activation in the sensorimotor network was observed in the patients with pSS compared with the controls. No correlation was found between fatigue and structural or functional changes of the brain. Conclusion pSS is associated with functional connectivity abnormalities of the somatosensory cortex and microstructural abnormalities in major white matter tracts, which are more pronounced in depression.

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