Biomaterial Database

The brain in fractal time: 1/f-like power spectrum scaling of the human electroencephalogram. 1992

W S Pritchard

Biobehavioral Division, R. J. Reynolds Tobacco Company, Winston Salem, NC 27102.

"1/f-like" power spectrum scaling is a ubiquitous feature of complex systems. In such scaling, the power spectrum of a given time series is dominated by an inverse power law, resulting in an inverse linear relation between log power and log frequency. The 1/f-like power spectrum scaling properties of human, resting eyes-closed and eyes-open EEG were examined. For both eyes-closed and eyes-open EEG, log power had a significant inverse linear relation with log frequency. The slope of this relation was not correlated with previously-calculated Grassberger-Procaccia dimension estimates for the same data, indicating that the EEG is not a 1/f-like stochastic process. Further, the degree of deviation from perfect log power versus log frequency linearity was related to power in the 8-12 Hz alpha frequency band. It is speculated that this deviation may be related to the low dimension of a chaotic alpha rhythm relative to other EEG rhythms.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009799	Ocular Physiological Phenomena	Processes and properties of the EYE as a whole or of any of its parts.	Ocular Physiologic Processes,Ocular Physiological Processes,Ocular Physiology,Eye Physiology,Ocular Physiologic Process,Ocular Physiological Concepts,Ocular Physiological Phenomenon,Ocular Physiological Process,Physiology of the Eye,Physiology, Ocular,Visual Physiology,Concept, Ocular Physiological,Concepts, Ocular Physiological,Ocular Physiological Concept,Phenomena, Ocular Physiological,Phenomenon, Ocular Physiological,Physiologic Process, Ocular,Physiologic Processes, Ocular,Physiological Concept, Ocular,Physiological Concepts, Ocular,Physiological Process, Ocular,Physiological Processes, Ocular,Physiology, Eye,Physiology, Visual,Process, Ocular Physiologic,Process, Ocular Physiological,Processes, Ocular Physiologic,Processes, Ocular Physiological
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D003700	Delta Rhythm	Brain waves seen on EEG characterized by a high amplitude and a frequency of 4 Hz and below. They are considered the "deep sleep waves" observed during sleep in dreamless states, infancy, and in some brain disorders.	Delta Rhythms,Rhythm, Delta,Rhythms, Delta
D004569	Electroencephalography	Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.	EEG,Electroencephalogram,Electroencephalograms
D005260	Female		Females
D005583	Fourier Analysis	Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)	Fourier Series,Fourier Transform,Analysis, Cyclic,Analysis, Fourier,Cyclic Analysis,Analyses, Cyclic,Cyclic Analyses,Series, Fourier,Transform, Fourier
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000513	Alpha Rhythm	Brain waves characterized by a relatively high voltage or amplitude and a frequency of 8-13 Hz. They constitute the majority of waves recorded by EEG registering the activity of the parietal and occipital lobes when the individual is awake, but relaxed with the eyes closed.	Alpha Rhythms,Rhythm, Alpha,Rhythms, Alpha