Longitudinal study of EEG frequency maturation and power changes in children on the Russian North

S I Soroko; N V Shemyakina; Zh V Nagornova; S S Bekshaev

doi:10.1016/j.ijdevneu.2014.08.012

Longitudinal study of EEG frequency maturation and power changes in children on the Russian North

Int J Dev Neurosci. 2014 Nov:38:127-37. doi: 10.1016/j.ijdevneu.2014.08.012. Epub 2014 Sep 8.

Authors

S I Soroko¹, N V Shemyakina², Zh V Nagornova¹, S S Bekshaev¹

Affiliations

¹ I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB RAS), Laboratory of Comparative Ecological and Physiological Studies, Toreza, 44, 194223 Saint-Petersburg, Russia.
² I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB RAS), Laboratory of Comparative Ecological and Physiological Studies, Toreza, 44, 194223 Saint-Petersburg, Russia. Electronic address: shemyakina_n@mail.ru.

PMID: 25219895
DOI: 10.1016/j.ijdevneu.2014.08.012

Abstract

The aim of the study was to reveal longitudinal changes in electroencephalogram spectral power and frequency (percentage frequency composition of EEG and alpha peak frequency) patterns in normal children from northern Russia. Fifteen children (9 girls and 6 boys) participated in the study. The resting state (eyes closed) EEGs were recorded yearly (2005-2013) from age 8 to age 16-17 for each child. EEG frequency patterns were estimated as the percentages of waves with a 1 Hz step revealed by measuring the interval durations between points crossing zero (isoline) by a curve. EEG spectral power changes were analyzed for delta (1.5-4 Hz), theta (4-7.5 Hz), alpha-1 (7.5-9.5 Hz), alpha-2 (9.5-12.5 Hz), beta-1 (12.5-18 Hz) and beta-2 (18-30 Hz) bands. According to the frequency composition of the EEG signals fast synchronous, polymorphous synchronous, polymorphous desynchronous and slow synchronous types of children EEG were revealed. These EEG types were relatively stable during adolescence. In these EEG types, the frequency patterns and spectral power dynamics with age had several common and specific features. Slow wave percentage and spectral power in the delta band remarkably decreased with age in all groups. Starting from the theta band the EEG types were characterized by different EEG spectral power changes with age. In fast synchronous EEG type, the theta and alpha-1 EEG power decreased, and the alpha-2 power increased in the occipital and parietal areas. The polymorphous synchronous type was characterized by increased both the alpha-1 and alpha-2 power with regional peculiarities. In the polymorphous desynchronous type spectral power in all bands decreased with age, and in the slow synchronous type, the alpha-1 power massively increased with age. Obtained results suggest predictive strength of the spatial-frequency patterns in EEG for its following maturation through the years.

Keywords: Alpha peak frequency; EEG frequency composition; EEG maturation; Longitudinal study; Spectral power.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Alpha Rhythm / physiology*
Brain / physiology*
Child
Electroencephalography*
Female
Fourier Analysis
Humans
Longitudinal Studies
Male
Russia