so that, for example, some rate of separation of points in the forward direction would approximate the rate of convergence in the time reversed data (Parlitz, 1992). Among the sources of spurious Lyapounov exponents are sample lengths that are too short and/or too measurement-noisy to compute a statistica

l- autonomic and the cognitive systems is enhanced in states after optic neuritis and early multiple sclerosis. Int J Neurosci, 86:87-93 Geist, K., Parlitz, U., Lauterborn, W. (1990) Comparison of different methods for computing Lyapunov exponents. Prog. Theor. Physics 83:875-893 Gershenfeld, N.A. (1992