Cross-spectral coherence during mental activity

John, E. Roy; Prichep, L.S.; Chabot, Robert J.; Easton, Paul A.

doi:10.1016/0013-4694(90)91967-t

Cited by 5 publications

(4 citation statements)

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“…The QEEG analyses were performed off-line. The fast Fourier transform and cross-spectral matrices were calculated every .39 Hz; the following QEEG measures were calculated for each subject: 1) AP, 2) RP and 3) MF, within the delta (1.56–3.89 Hz), theta (3.90–7.50 Hz), alpha (7.51–12.50 Hz) and beta (12.51–19.15 Hz) frequency bands for each referential channel [ 6 , 11 , 42 – 44 ]; in addition, total MF was computed. The geometric power [ 45 ] of each individual was subtracted from his/her cross-spectral matrix to obtain the AP value in each band for each electrode; this correction reduces 42% of the variance that is not associated with physiological factors.…”

Section: Methodsmentioning

confidence: 99%

High levels of incidental physical activity are positively associated with cognition and EEG activity in aging

et al. 2018

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High levels of physical activity seem to positively influence health and cognition across the lifespan. Several studies have found that aerobic exercise enhances cognition and likely prevents cognitive decline in the elderly. Nevertheless, the association of incidental physical activity (IPA) with health and cognition during aging has not been studied. Thus, the aim of this study was to evaluate the association of IPA level with cognitive functions and resting electroencephalogram (EEG) in healthy old participants. Participants (n = 97) with normal scores on psychometric and neuropsychological tests and normal values in blood analyses were included. A cluster analysis based on the scores of the Yale Physical Activity Scale (YPAS) allowed the formation of two groups: active, with high levels of IPA, and passive, with low levels of IPA. Eyes-closed resting EEG was recorded from the participants; the fast Fourier transform was used offline to calculate absolute power (AP), relative power (RP), and mean frequency (MF) measures. There were no differences in socioeconomic status, cognitive reserve, general cognitive status, or lipid and TSH profiles between the groups. The results of cognitive tests revealed significant differences in the performance variables of the WAIS scores (p = .015), with advantages for the active group. The resting EEG exhibited significantly slower activity involving the frontal, central, and temporal regions in the passive group (p < .05). Specifically, higher delta RP (F7, T3), lower delta MF (F4, C4, T4, T6, Fz, Cz), higher theta AP (C4), higher theta RP (F4, C4, T3, Fz), lower alpha AP (F3, F7, T3), lower alpha RP (F7), and lower total MF (F3, F7, T3, T5, Fz) were found. Altogether, these results suggest that IPA induces a neuroprotective effect, which is reflected both in behavioral and electrophysiological variables during aging.

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Section: Methodsmentioning

confidence: 99%

High levels of incidental physical activity are positively associated with cognition and EEG activity in aging

et al. 2018

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“…We selected 20-24 EEG state closed-eyes segments (without artifact) of 2.56 s from each individual for quantitative EEG analysis by visual inspection. A minute of artifact-free EEG is considered the minimum amount of EEG required to obtain reliable quantitative measures (John et al, 1987; Nuwer et al, 1994). Fast Fourier Transform (FFT) was applied to obtain the cross spectral matrixes of all individual recordings, and were calculated with a spectral resolution of 0.39 Hz, from 0.78 to 19.53 Hz.…”

Section: Methodsmentioning

confidence: 99%

EEG Signatures of COVID-19 Survival compared to close contacts and the Cuban EEG normative database

Calzada-Reyes,

Galán-García,

Virués-Alba

et al. 2024

Preprint

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BackgroundThe EEG constitutes a powerful neuroimaging technique for assessing functional brain impairment in COVID-19 patients.ObjectiveThe current investigation compared the EEG among COVID-19 survivors, close contacts and the Cuban EEG normative database, using semi-quantitative visual EEG inspection, quantitative and the current source density measures EEG analysis.MethodsThe resting-state EEG activity, quantitative QEEG, and VARETA inverse solution, were evaluated in 173 subjects: 87 patients confirmed cases by the positive reverse transcription polymerase chain reaction (RT-PCR), 86 close contacts (negative PCR) and the Cuban EEG normative database. All patients were physical, neurological, and clinically assessed using neurological retrospective survey and version 2.1 of the Schedules for Clinical Assessment in Neuropsychiatry (SCAN).ResultsThe GTE score showed significant differences in terms of frequency scores of backgrounds rhythmic activity, diffuse slow activity, and focal abnormality. The QEEG analysis showed a pattern of abnormality with respect to the Cuban EEG normative values, displaying an excess of alpha and beta activities in the fronto-central-parietal areas in both groups. The anomalies, of COVID-19 patients and close contacts, differs in the right fronto-centro parietal area. The COVID 19 group differed-s from the close control group in theta band of the right parieto-central. The symptomatic group of COVID-19 patients differs from asymptomatic patients in delta and theta activities of the parieto-central region. The sources of activation using VARETA showed a difference in cortical activation patterns at alpha and beta frequencies in the groups studied with respect to the normative EEG database. In beta frequency were localized in right middle temporal gyrus in both groups and right angular gyrus in Covid 19 group only. In alpha band, the regions were the left supramarginal gyrus for Covid 19 group and the left superior temporal gyrus for Control group. Greater activation was found in the right middle temporal gyrus at alpha frequency in COVID-19 patients than in their close contacts.ConclusionsBrain functions are impaired in long COVID-19 patients. QEEG and VARETA permit us to comprehend the susceptibility of particular brain regions exposed to viral illness.HighlightsBackground frequency abnormalities diffuse slow activity and focal abnormality associated with a pattern of excess oftheta, alpha and beta energies in in the right fronto-centro-parietal regions in QEEG analysis characterizedCOVID-19 patients.Patients with COVID-19 show more alpha and beta EEG activities related to normative EEG database.Patients with COVID-19 and close contacts show high cortical activation in temporo-parietal areas in alpha and beta bands compared to normative EEG database.Patients with COVID-19 (positive PCR) have high activation in the right middle frontal gyrus for alpha band related to close contacts.

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“…Comparison of clinical variables between the FRS(+) and FRS(-) groups was done using Independent t-test and Fisher's exact test. As the spectral power and coherence data were not normally distributed (Shapiro-Wilk test), normalization was achieved by log and Fisher's z transformation, respectively, as recommended by 'neurometrics' 28,29. The schizophrenia group (SCZ, n=37) was compared with healthy controls using Independent t-test on spectral power data (transformed).…”

Section: Methodsmentioning

confidence: 99%

“…As the spectral power and coherence data were not normally distributed (Shapiro-Wilk test), normalization was achieved by log and Fisher's z transformation, respectively, as recommended by 'neurometrics'. 28 , 29 The schizophrenia group (SCZ, n=37) was compared with healthy controls using Independent t-test on spectral power data (transformed). Multifactorial ANOVA for comparison of two subgroups with healthy controls was performed with gamma band frequency (3 levels: low, high 1, and high 2), laterality (2 levels: right and left) and regions (4 levels-frontal, parietal, temporal and occipital).…”

Section: Methodsmentioning

confidence: 99%

Schneiderian First Rank Symptoms and Gamma Oscillatory Activity in Neuroleptic Naïve First Episode Schizophrenia: A 192 Channel EEG Study

Tikka

Yadav

Nizamie

et al. 2014

Psychiatry Investig

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ObjectiveSchneiderian first-rank symptoms (FRS) and abnormal EEG gamma activity in schizophrenia have been reported independently to have a neurodevelopmental basis. We aimed to investigate spontaneous gamma power in two groups of first episode schizophrenia patients (those who experience FRS and those who do not).MethodsA comparative hospital based study having 37neuroleptic naïve male patients with schizophrenia divided into two groups-FRS(+) and FRS(-) groups based on the presence of FRS. Thirty age, sex, education and handedness matched individuals served as controls (N). All participants underwent a 192-channel resting Electroencephalography (EEG) recording. Gamma spectral power was calculated for low- (30-50 Hz) and high-gamma 1 & 2 (51-70 and 71-100 Hz) bands. Spectral power was compared between three groups using MANOVA and supplementary one-way ANOVA with Bonferroni test controlling for multiple comparisons. Linear regression was used to identifying predictor variables for FRS. Pearson correlation coefficient was computed between spectral power parameters and various clinical variables.ResultsSignificantly higher high gamma band-1 power was observed over right frontal (p<0.05), parietal (p<0.05) and temporal (p<0.05) regions in FRS(+) than FRS(-) group and normal controls. Right parietal high gamma-1 power and paranoid cluster on PANSS significantly predicted number of FRS in total schizophrenia patients; paranoid cluster on PANSS showed significant correlation with number of FRS in FRS(+) group.ConclusionFindings of our study add to the evidence that areas contained within the hetero modal association cortex are associated with FRS. The study findings also strengthen the neurodevelopmental basis of FRS in schizophrenia.

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Cross-spectral coherence during mental activity

Cited by 5 publications

References 0 publications

High levels of incidental physical activity are positively associated with cognition and EEG activity in aging

High levels of incidental physical activity are positively associated with cognition and EEG activity in aging

EEG Signatures of COVID-19 Survival compared to close contacts and the Cuban EEG normative database

Schneiderian First Rank Symptoms and Gamma Oscillatory Activity in Neuroleptic Naïve First Episode Schizophrenia: A 192 Channel EEG Study

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