Distribution of Variables Extracted from Spectral EEG-Analysis

Ferber, Georg; Eichholz, Geoffrey G.

doi:10.1055/s-0038-1635726

Cited by 5 publications

(3 citation statements)

References 2 publications

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“…We conducted statistical comparisons of the aforementioned outcome measures between the wet and dry EEG systems by means of Wilcoxon's sign rank test, as this non-parametric test does not assume normal distributions. In particular, spectral band power values do not meet this assumption 39 . Accordingly, in the results section we report the z-value of the approximating normal distribution associated with the sign rank test and its corresponding p-value.…”

Section: Data Processing All Numerical Processing Was Done Using Matmentioning

confidence: 99%

Comparison between a wireless dry electrode EEG system with a conventional wired wet electrode EEG system for clinical applications

Hinrichs

Scholz

Baum

et al. 2020

Sci Rep

139

101

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Dry electrode electroencephalogram (EEG) recording combined with wireless data transmission offers an alternative tool to conventional wet electrode EEG systems. However, the question remains whether the signal quality of dry electrode recordings is comparable to wet electrode recordings in the clinical context. We recorded the resting state EEG (rsEEG), the visual evoked potentials (VEP) and the visual P300 (P3) from 16 healthy subjects (age range: 26-79 years) and 16 neurological patients who reported subjective memory impairment (age range: 50-83 years). Each subject took part in two recordings on different days, one with 19 dry electrodes and another with 19 wet electrodes. They reported their preferred EEG system. Comparisons of the rsEEG recordings were conducted qualitatively by independent visual evaluation by two neurologists blinded to the EEG system used and quantitatively by spectral analysis of the rsEEG. The P100 visual evoked potential (VEP) and P3 event-related potential (ERP) were compared in terms of latency, amplitude and pre-stimulus noise. The majority of subjects preferred the dry electrode headset. Both neurologists reported that all rsEEG traces were comparable between the wet and dry electrode headsets. Absolute Alpha and Beta power during rest did not statistically differ between the two EEG systems (p > 0.05 in all cases). However, Theta and Delta power was slightly higher with the dry electrodes (p = 0.0004 for Theta and p < 0.0001 for Delta). For ERPs, the mean latencies and amplitudes of the P100 VEP and P3 ERP showed comparable values (p > 0.10 in all cases) with a similar spatial distribution for both wet and dry electrode systems. These results suggest that the signal quality, ease of setup and portability of the dry electrode EEG headset used in our study comply with the needs of clinical applications. The quality of scalp electroencephalogram (EEG) recordings critically depends on the connection between the amplifier input and the skin surface. Wet electrodes that rely on conductive gel to guarantee low impedance levels (<10 KOhm) remain the gold standard for clinical recordings. However, EEG recording with wet electrodes requires skin abrasion, gel application, impedance optimization and cleaning after recording, all of which are time consuming. Trained EEG technicians are therefore recommended for wet electrode EEG setup and acquisition (for instance, see 1-3). However, this presents a barrier to realising diagnostic strategies that propose replacing EEG recordings in the clinic or the doctor's office with EEG recordings in the patient's home, which saves both time and costs as well as improving the patient's health care and comfort 4,5. To achieve reliable home-based EEG recording, electrodes must be easy to apply and provide stable data quality over long recording sessions. The same standards hold for other applications, including repeated EEG

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Section: Data Processing All Numerical Processing Was Done Using Matmentioning

confidence: 99%

Comparison between a wireless dry electrode EEG system with a conventional wired wet electrode EEG system for clinical applications

Hinrichs

Scholz

Baum

et al. 2020

Sci Rep

139

101

View full text Add to dashboard Cite

show abstract

“…In general, quantitative variables which do not have a unimodal distribution should be avoided [25]. If parametric methods are considered, a fairly symmetric distribution is required.…”

Section: Sample Distributionsmentioning

confidence: 99%

IPEG Guideline on Statistical Design and Analysis for Pharmacodynamic Trials

Ferber¹,

K²,

Fichte³

et al. 1999

Neuropsychobiology

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“…Summarizing by means of a sign test takes into account the large betweenpatient variability in reaction to psychotropic drugs, as well as the problems which may arise from the statistical distributions of EEG parameters [see Ferber and Eichholz, 1976;Gasser et al, 1982] and of plasma concentra tion values. In view of the small sample fulfilling the criteria for evaluability, it is not surprising that only a few p values lower than 0.05 are obtained; this is the price which has to be paid in this evaluation for the use of a nonparametric method.…”

Section: Discussionmentioning

confidence: 99%

Investigation of the Effect of Fluperlapine on the EEG in Schizophrenic Patients

Ferber¹,

Matejcek²,

Krebs

et al. 1987

Neuropsychobiology

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The investigations of the EEG during an open study with the antipsychotic drug fluperlapine in acute schizophrenic patients are reported. Due to ethical and practical considerations some of the common pharmacoelectroencephalographic procedures as well as placebo controlled study designs could not be applied in these patients. To overcome at least partly these limitations, intraindividual as well as interindividual correlations were used. They were computed between plasma concentrations of unchanged fluperlapine as well as its metabolite N-oxide fluperlapine, on one hand, and EEG variables, on the other. The intraindividual correlations can be computed either on the first day of the active treatment over various time points of that day (acute effects) or across several appointed treatment days always taking values at the same time during these days (chronic effects). The intraindividual correlations of a set of subjects were submitted to a sign test to obtain an overall result for the relation between the EEG and blood plasma levels of the drug. In this way an acute and a chronic effect of fluperlapine on the EEG could be shown consisting mainly of an increase in slow waves, a decrease in the α-activity and a tendency of β-activity to decrease. A comparison of the correlations between the plasma levels of fluperlapine and the EEG variables with the correlations between the plasma levels of N-oxide fluperlapine and the EEG give rise to the hypothesis that unchanged fluperlapine has a stronger effect on the EEG than its metabolite.

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Distribution of Variables Extracted from Spectral EEG-Analysis

Cited by 5 publications

References 2 publications

Comparison between a wireless dry electrode EEG system with a conventional wired wet electrode EEG system for clinical applications

Comparison between a wireless dry electrode EEG system with a conventional wired wet electrode EEG system for clinical applications

IPEG Guideline on Statistical Design and Analysis for Pharmacodynamic Trials

Investigation of the Effect of Fluperlapine on the EEG in Schizophrenic Patients

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