Bilateral frontal theta-waves in EEG of 7–8-year-old children with learning difficulties: Qualitative and quantitative analysis

Abstract

We analyzed EEG recorded in the rest condition (eye closed) in 22 children aged from 7 to 8 years old who experienced learning difficulties and whose EEG recordings were characterized by sporadic short term appearance of bilateral synchronous slow waves over the frontal and/or frontal and central corticesfrontal theta waves (FTW). The vector autoregressive modeling was used in order to assess the strength of directed cortico cortical functional connectivity pattern for FTW and for surrounding EEG. The comparison of the two patterns showed that FTW is characterized by diffuse strengthening of the functional links connect ing frontal, central and (to some extent) temporal cortices as well as the links directed to the above regions from the other cortical areas. The results of the study suggest that FTW is most probably caused by the com mon for the frontal and central cortices neuronal theta activity synchronized via cortico subcortical links. This suggestion is in a good agreement with the view that FTW reflects the alterations in functioning of fronto thalamic system.Keywords: human EEG, frontal theta waves, fronto thalamic system, cortico cortical functional connectiv ity, vector autoregressive model, 7 8 year old children.

The influence of the functional state of brain regulatory systems on the programming, selective regulation and control of cognitive activity in children: I. Neuropsychological and EEG analysis of age-related changes in brain regulatory functions in children aged 9–12 years

“…In our previous study we ana lyzed clinical and experimental neurophysiological arguments for the fronto thalamic origin of this type of EEG changes [29].…”

Quantitative measures of cortical functional connectivity: A state-of-the-art brief survey

“…Study [16] has shown that the VAR model can resolve the autospectrum of channel k for M channels (of electroencephalographic leads) into independent components where the detached summand reflects the off diagonal matrix V of the covariance matrix of autore gressive residuals, and function corresponds to the contribution of channel n to the autospectrum of channel k.…”

“…(15), , t) of the x(t) signal is con structed by the same principle as the Fourier transform but, in contrast to it, depends on two arguments: fre quency and time. As in the framework of frequency analysis, the cross spectrum is defined as = and the complex coherence func tion is defined as (16) Equation (16), similarly to the traditional coherence function (1), implies that the values in the terms of the fraction are exposed to preliminary statistical averag ing. Statistical connection may be assessed using the absolute value (16), as well as its real or imaginary parts.…”

“…As in the framework of frequency analysis, the cross spectrum is defined as = and the complex coherence func tion is defined as (16) Equation (16), similarly to the traditional coherence function (1), implies that the values in the terms of the fraction are exposed to preliminary statistical averag ing. Statistical connection may be assessed using the absolute value (16), as well as its real or imaginary parts. Since the coherence function (16) depends on two arguments (frequency and time), it is represented as a surface or a map, where the value is encoded by color or intensity.…”

“…The experimental studies in recent years show that the measures of frequency specific directed influence based on the VAR model are a prospective tool for the analysis of EEG, MEG [16,17,34,[39][40][41][42][43][44], and fMRI data [45,46]. The underlying principle of the VAR model, the rank of this method among other methods, and the practical aspects of its application are discussed in several reviews [18,34,47].…”