title: Age-Related Changes in Electroencephalographic Signal Complexity.
abstract: The study of active and healthy aging is a primary focus for social and neuroscientific communities. Here, we move a step forward in assessing electrophysiological neuronal activity changes in the brain with healthy aging. To this end, electroencephalographic (EEG) resting state activity was acquired in 40 healthy subjects (age 16-85). We evaluated Fractal Dimension (FD) according to the Higuchi algorithm, a measure which quantifies the presence of statistical similarity at different scales in temporal fluctuations of EEG signals. Our results showed that FD increases from age twenty to age fifty and then decreases. The curve that best fits the changes in FD values across age over the whole sample is a parabola, with the vertex located around age fifty. Moreover, FD changes are site specific, with interhemispheric FD asymmetry being pronounced in elderly individuals in the frontal and central regions. The present results indicate that fractal dimension well describes the modulations of brain activity with age. Since fractal dimension has been proposed to be related to the complexity of the signal dynamics, our data demonstrate that the complexity of neuronal electric activity changes across the life span of an individual, with a steady increase during young adulthood and a decrease in the elderly population.
authors.affiliation: Dept. of Neuroscience, Imaging and Clinical Sciences, 'G. d'Annunzio' University, Chieti, Italy.|Institute for Advanced Biomedical Technologies, 'G. d'Annunzio' University, Chieti, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Zappasodi
authors.affiliation: Dept. of Neuroscience, Imaging and Clinical Sciences, 'G. d'Annunzio' University, Chieti, Italy.|Institute for Advanced Biomedical Technologies, 'G. d'Annunzio' University, Chieti, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Marzetti
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Olejarczyk
authors.affiliation: Laboratory of Electrophysiology for Translational neuroScience (LET'S), ISTC, National Research Council (CNR), Rome, Italy.|Unit of Imaging, IRCCS San Raffale Pisana, Cassino, Italy.
authors.forename: Franca
authors.initials: F
authors.lastname: Tecchio
authors.affiliation: Dept. of Neuroscience, Imaging and Clinical Sciences, 'G. d'Annunzio' University, Chieti, Italy.|Institute for Advanced Biomedical Technologies, 'G. d'Annunzio' University, Chieti, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Pizzella
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult