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Individual analysis of EEG background‐activity within school age: impact of age and sex within a longitudinal data set
Author(s) -
Gmehlin Dennis,
Thomas Christine,
Weisbrod Matthias,
Walther Stephan,
Pfüller Ute,
Resch Franz,
OelkersAx Rieke
Publication year - 2011
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2010.11.005
Subject(s) - electroencephalography , psychology , alpha (finance) , longitudinal study , audiology , developmental psychology , beta (programming language) , statistics , mathematics , medicine , neuroscience , psychometrics , construct validity , computer science , programming language
Objectives Quantitative EEG can monitor changes in brain function during development and may help to understand developmental disorders. However, current EEG‐databases are primarily based on standardized frequency bands which disregard age‐related changes in alpha peak frequency (PF) and therefore complicate the interpretation of spectral estimates in the theta and alpha range. Methods We used a two point longitudinal design in order to analyze intraindividual changes in 40 healthy children and adolescents with age (T 1 : 6–18 years; interval approximately 4 years). Using a 64‐channel eyes closed resting EEG we calculated absolute/relative power in individualized frequency bands (IFB: delta, theta, alpha 1/2 and beta) based on PF. Results PF increased with age, with changes being larger for children than adolescents. Controlling for changes in PF, changes in absolute/relative alpha 1/2 power and in absolute beta power were minor. Relative beta power, however, increased while absolute/relative delta and theta power decreased massively. Sex‐differences in PF did not reach significance. However, boys exhibited larger changes during adolescence than girls for all absolute power measures except alpha. Conclusion Normal EEG development during school‐age is mainly based on an absolute decrease of slow frequency activity and increases of PF which may be interpreted in terms of a reorganization of the EEG towards a higher frequency oscillatory scale rather than a maturation of the theta–alpha 1/2 band power sequence. Age‐related changes differed between boys and girls suggesting a different developmental timing for the sexes. In future studies a combined analysis of PF and IFB may help to specify deviations in developmental disorders.