1. A method of brain stimulation for treatment of a neurological disease, comprising: (a) stimulating neurons in a brain region; (b) measuring or calculating a phase response curve for a population of interest of said stimulated neurons; and (c) calculating by a computer programmed device and using said measured or calculated phase response curve, stimulus parameters and waveforms to synchronize or desynchronize neuronal oscillators in said brain region, wherein said calculation is based on a Lyapunov exponent described in terms of said measured or calculated phase response curve.