ep EEG. Sleep 15:95-101 Roschke, J., Aldenhoff, J.B. (1993) Estimation of the dimensionality of sleep-EEG data in schizophrenics Eur Arch Psychiatry Clin Neurosci 242:191-196 Roschke, J., Fell, J., Mann, K. (1997) Non-linear dynamics of alpha and theta rhythm: correlation dimensions and Lyapunov exponents from