1. A neurostimulation system, comprising: a plurality of electrical terminals configured for being electrically coupled to a plurality of electrodes; output stimulation circuitry configured for conveying electrical energy between the electrodes, thereby creating a stimulation region in tissue of a patient when the electrodes are located adjacent the tissue; monitoring circuitry configured for sensing a cognitive brain signal; and control circuitry configured for analyzing the sensed cognitive brain signal and for controlling the output stimulation circuitry to displace a locus of the stimulation region relative to the tissue based on the analysis of the sensed cognitive brain signal.