1. An apparatus for stimulating neurons with a pathologically synchronous and oscillatory neural activity, comprising: a stimulation unit having a plurality of stimulation contacts for stimulating neurons in at least one of a brain and a spinal cord of a patient using electrical stimuli; a measuring unit for recording measured signals, the measured signals reproducing a neural activity of the stimulated neurons; and a control and analysis unit for controlling the stimulation unit and for analyzing the measured signals, wherein the control and analysis unit is configured to: control the stimulation unit to apply the electrical stimuli using the stimulation contacts; select the stimulation contacts, whose electrical stimuli effect a phase reset of the pathologically synchronous and oscillatory neural activity of the respective stimulated neurons based on the measured signals recorded in response to the application of the electrical stimuli; control the stimulation unit such that the selected stimulation contacts apply phase resetting stimuli pairwise with a time offset; determine, based on measured signals recorded by the measuring unit in response to application of the phase resetting stimuli, whether the applied phase resetting stimuli suppress the pathologically synchronous and oscillatory neural activity of the respective stimulated neurons; determine, based on the measured signals recorded in response to the phase-resetting stimuli by a pair of stimulation contacts, whether the phase resetting stimuli effect an increase in the pathologically synchronous and oscillatory activity of the neurons; and select the stimulation contacts that are determined to suppress the pathologically synchronous and oscillatory neural activity of the respective stimulated neurons.