Reliability of quantitative EEG features

Guđmundsson, Steinn; Rúnarsson, Thomas Philip; Sigurðsson, Sven; Eiriksdottir, Gudrun; Johnsen, Kristinn

doi:10.1016/j.clinph.2007.06.018

Cited by 179 publications

(122 citation statements)

References 25 publications

Supporting

Mentioning

110

Contrasting

Unclassified

Order By: Relevance

“…Lower frequency delta activity is less reliable according to some authors (Pollock et al, 1991, Gudmundsson et al, 2007. In contrast, Lewis and colleagues (2007) found higher frequency alpha was less reliable than other EEG bands.…”

Section: Neurosky Thinkgear Retest Reliabilitymentioning

confidence: 95%

“…This normative data from across the lifespan during both resting and active EEG tasks can be used to reliably detect change in repeated measurements. The low CR values also suggest the stability of qEEG obtained from the ThinkGear system is a potentially sensitive biological marker for tracking longitudinal changes deviant from healthy individuals, but this requires further investigation (Cannon et al, 2012, Gudmundsson et al, 2007.…”

Section: Boundaries Of a True-changementioning

confidence: 99%

See 1 more Smart Citation

Test-retest reliability of a single-channel, wireless EEG system

Rogers

Johnstone

Aminov

et al. 2016

International Journal of Psychophysiology

101

View full text Add to dashboard Cite

Recording systems to acquire electroencephalogram (EEG) data are traditionally lab-based. However, there are shortcomings to this method, and the ease of use and portability of emerging wireless EEG technologies offer a promising alternative. A previous validity study demonstrated data derived from a single-channel, wireless system (NeuroSky ThinkGear, San Jose, California) is comparable to EEG recorded from conventional lab-based equipment. The current study evaluated the reliability of this portable system using test-retest and reliable change analyses. Relative power (RP) of delta, theta, alpha, and beta frequency bands was derived from EEG data obtained from a single electrode over FP1 in 19 healthy youth (10-17 years old), 21 healthy adults (18-28 years old), and 19 healthy older adults (55-79 years old), during eyes-open, eyesclosed, auditory oddball, and visual n-back conditions. Intra-class correlations (ICCs) and Coefficients of Repeatability (CRs) were calculated from RP data re-collected one-day, one-week, and one-month later. Participants' levels of mood and attention were consistent across sessions. Eyes-closed resting EEG measurements using the portable device were reproducible (ICCs 0.76-0.85) at short and longer retest intervals in all three participant age groups. While still of at least fair reliability (ICCs 0.57-0.85), EEG obtained during eyes-open paradigms was less stable, and any change observed over time during these testing conditions can be interpreted utilizing the CR values provided. Combined with existing validity data, these findings encourage application of the portable EEG system for the study of brain function.

show abstract

Section: Neurosky Thinkgear Retest Reliabilitymentioning

confidence: 95%

Section: Boundaries Of a True-changementioning

confidence: 99%

Test-retest reliability of a single-channel, wireless EEG system

Rogers

Johnstone

Aminov

et al. 2016

International Journal of Psychophysiology

101

View full text Add to dashboard Cite

show abstract

“…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 6 . Diminished coherence between two regions probably indicates a decrease in their functional correlations 1,7 . It is possible to calculate the ordinary coherence between two brain electrodes that are placed in the same hemisphere, or in homologous areas, through a mathematical formula that divides the cross-spectrum of these two channels by the product of the auto-spectrum of each of the same channels, as demonstrated by the formula below:…”

mentioning

confidence: 99%

Alpha band EEG coherence in healthy nonagenarians

Jorge

Spíndola

Katata³

et al. 2017

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

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...

show abstract

“…All EEG records were then bandpass-filtered to 1-40 Hz as the signals below 1 Hz and above 40 Hz in EEG are generally unreliable due to low signal-to-noise ratio [22], [23]. The records were rereferenced to common average reference to approximate a reference-free recording condition [23], to minimize the artifacts [24], [25], to make channel records independent i.e., to make channel records to represent local activities [24], [26], and to provide high reliability over quantitative EEG features [27]. Finally a 10-minute, artifact-free epoch from each EEG record was retained for the analysis.…”

Section: B Preprocessingmentioning

confidence: 99%