title: Complexity of visual stimuli and non-linear EEG dynamics in humans.
abstract: The effects of stimulus complexity on the nonlinear electrical brain (EEG) dynamics were investigated in a sample of 24 healthy volunteers. Stimuli used were either a single mechanical low-friction pendulum with a periodic movement (temporal frequency about 1 Hz) or a double-pendulum with a chaotic movement, which were observed for 2-3 min in each case. The prediction that a more complex visual stimulus (double-pendulum) increases the dimensional complexity of brain activity as compared to a simple visual stimulus (single-pendulum), was confirmed by determination of pointwise correlation dimension. Further, there was a significant decrease of alpha power in the double-pendulum compared to a single-pendulum condition. Moreover, a correlation analysis showed a positive correlation between EEG complexity and beta power over the whole cortex in the single- and, above all, in the double-pendulum condition, and also a positive correlation between dimensional complexity and alpha power in the double-pendulum condition only, particularly in the brain regions responsible for the 'bottom-up' sustained attention processes.
authors.affiliation: Institute of Medical Psychology and Behavioral Neurobiology, Eberhard-Karls University of Tübingen, Gartenstrasse 29, 72074, Tübingen, Germany. viktor.meuller@uni-tuebingen.de
authors.forename: Viktor
authors.initials: V
authors.lastname: Müller
authors.forename: Werner
authors.initials: W
authors.lastname: Lutzenberger
authors.forename: Hubert
authors.initials: H
authors.lastname: Preissl
authors.forename: Friedemann
authors.initials: F
authors.lastname: Pulvermüller
authors.forename: Niels
authors.initials: N
authors.lastname: Birbaumer
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D000704:Analysis of Variance; D001611:Beta Rhythm; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004569:Electroencephalography / Q000145:classification / Q000379:methods; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D010507:Periodicity; D010775:Photic Stimulation; D012815:Signal Processing, Computer-Assisted; D013223:Statistics as Topic / Q000379:methods