Differentiation of linearly correlated noise from chaos in a biologic system using surrogate data.
Experimental time-series of human H-reflexes were analyzed for the presence of fractal structure or deterministic chaos. Surrogate data sets consisting of stochastic time-series with preservation of selected properties of the experimental time-series were used as mathematical controls. Artifacts generated during the analysis of the experimental data are identified, and shown to be due to linear correlation in the original time-series. The method is simple and generally applicable to the non-linear analysis of time-series from any experimental system.
Schiff
S J
SJ
Department of Neurosurgery, Children's National Medical Center, Washington, DC 20010.
Chang
T
T
D000465:Algorithms; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008433:Mathematics; D008959:Models, Neurological; D013269:Stochastic Processes