The EEG in acallosal children. Coherence values in the resting state: left hemisphere compensatory mechanism?

Koeda, Tatsuya; Knyazeva, Maria G.; Njiokiktjien, C; Jonkman, E.J.; Sonneville, Leo de; Vildavsky, V.

doi:10.1016/0013-4694(95)00171-9

Cited by 85 publications

(44 citation statements)

References 31 publications

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“…Koeda et al 23 and Montplaisir et al 24 demonstrated the importance of the corpus callosum in this analysis. These authors showed that individuals with agenesis of the corpus callosum, or those who were subjected to partial corpus callosotomy, presented with reduced interhemispheric coherence.…”

Section: Discussionmentioning

confidence: 82%

Alpha band EEG coherence in healthy nonagenarians

Jorge

Spíndola

Katata³

et al. 2017

Arq. Neuro-Psiquiatr.

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Brain tissue has an enormous quantity of connections between neurons. These become established so that neuronal activities become synchronous and different brain areas can communicate. One of the mathematical parameters that enable measurement of this connectivity is electroencephalographic (EEG) coherence. Several published studies have suggested that this coherence decreases through the aging process, with reduction of the neuron population 1 . Life expectancy in Brazil has increased over recent years and, consequently, the population of nonagenarians has increased. Therefore, there is a need for knowledge of the neurophysiological characteristics of EEG signals in cognitively normal individuals of this age.Investigation of EEG coherence enables measurement of the correlation between different brain areas. This is done through examining the mutual relationship between two EEG signals for different frequency bands. Quadratic or ordinary coherence consists of measurement of the covariance of spectral power between two pairs of electrodes 1,2,3 . Because coherence is a normative value for the power of a given frequency, it is independent of the amplitude oscillations of the signal 4,5 . Thus, this property makes coherence a relatively safe method for comparing groups of individuals, because differences in EEG potency do not affect the estimated coherence value ABSTRACT Electroencephalographic (EEG) coherence is a parameter that enables evaluation of cerebral connectivity. It may be related to the functional state of the brain. In the elderly, it may reflect the neuronal loss caused by aging. Objective: To describe characteristics of coherence in nonagenarians. Methods: We evaluated interhemispheric coherence for the alpha band in 42 cognitively normal individuals aged 90 to 101 years. Coherence values in the occipital electrode (O1O2), in the resting state with closed eyes, were calculated by means of spectral analysis using digital EEG EMSA 32 channels, 12 bits and a frequency of 200 Hz. Results: The mean coherence value for the alpha band at O1O2 was 0.65 (SD 0.13). No significant differences were found between men and women. Conclusions: The findings from this study did not show any decrease in interhemispheric coherence for the alpha band in cognitively normal nonagenarians. This may be useful as a standard value for this age group.Keywords: electroencephalography; aged, 80 and over; health of the elderly; aging. RESUMOA coerência é um parâmetro que permite avaliar a conectividade cerebral, podendo se relacionar com o estado funcional do cérebro.Especialmente nos idosos, pode refletir a perda neuronal decorrente do envelhecimento. Objetivo: Descrever características da coerência em nonagenários. Métodos: Avaliamos a coerência interhemisferica para a banda alfa em 42 indivíduos cognitivamente normais entre 90 e 101 anos. Foram calculados através da análise espectral o valor da coerência nos eletrodos O1O2, em estado de repouso e olhos fechados, com EEG digital 32 canais marca EMSA 12 bits e frequência de amost...

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Section: Discussionmentioning

confidence: 82%

Alpha band EEG coherence in healthy nonagenarians

Jorge

Spíndola

Katata³

et al. 2017

Arq. Neuro-Psiquiatr.

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“…Reduced theta and beta coherence is also associated with nonneurological disorders such as depression [18]. Generally speaking, interhemispheric coherence is shown to represent the degree of connectivity between brain hemispheres [20,26]. This connectivity represents functional interactions and coupling between different brain areas.…”

Section: Discussionmentioning

confidence: 99%

Electroencephalographic Power and Coherence Analyses Suggest Altered Brain Function in Abstinent Male Heroin-Dependent Patients

et al. 2004

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Previous studies have shown that drug abuse is associated with altered brain function. However, studies of heroin abuse-related brain dysfunctions are scarce. Electroencephalographic (EEG) power and coherence analyses are two important tools for examining the effects of drugs on brain function. In the present study, we compared EEG power and coherence measures of 18 abstinent heroin-dependent subjects with those of 12 healthy control subjects. Furthermore, within the heroin group, associations between heroin use in the past, heroin craving and these EEG measures were studied. The results show that heroin-dependent subjects have increased relative beta-2 power and increased left intrahemispheric gamma coherence compared with control subjects. Furthermore, coherence measures showed correlations with clinical variables. These EEG abnormalities may reflect underlying changes in brain function due to long-term drug abuse and premorbid characteristics.

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“…This technique is based on low-frequency interregional correlations in EEG as well as BOLD T2*-weighted MRI (Biswal, 1995;Koeda, 1995). Although, it cannot establish a causal relationship between brain regional activity, it can demonstrate interactions (Friston, 1996b).…”

Section: Introductionmentioning

confidence: 99%

Reduced functional connectivity between V1 and inferior frontal cortex associated with visuomotor performance in autism

et al. 2005

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Some recent evidence has suggested abnormalities of the dorsal stream and possibly the mirror neuron system in autism, which may be responsible for impairments of joint attention, imitation, and secondarily for language delays. The current study investigates functional connectivity along the dorsal stream in autism, examining interregional blood oxygenation level dependent (BOLD) signal cross-correlation during visuomotor coordination. Eight high-functioning autistic men and 8 handedness and age-matched controls were included. Visually prompted button presses were performed with the preferred hand. For each subject, functional connectivity was computed in terms of BOLD signal correlation with the mean time series in bilateral visual area 17. Our hypothesis of reduced dorsal stream connectivity in autism was only in part confirmed. Functional connectivity with superior parietal areas was not significantly reduced. However, the autism group showed significantly reduced connectivity with bilateral inferior frontal area 44, which is compatible with the hypothesis of mirror neuron defects in autism. More generally, our findings suggest that dorsal stream connectivity in autism may not be fully functional.

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The EEG in acallosal children. Coherence values in the resting state: left hemisphere compensatory mechanism?

Cited by 85 publications

References 31 publications

Alpha band EEG coherence in healthy nonagenarians

Alpha band EEG coherence in healthy nonagenarians

Electroencephalographic Power and Coherence Analyses Suggest Altered Brain Function in Abstinent Male Heroin-Dependent Patients

Reduced functional connectivity between V1 and inferior frontal cortex associated with visuomotor performance in autism

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