A preferred frequency is identified, beingusable to stimulate a neurological target within a mammalianbody using at least one microelectrode positionedat or near the target. To establish efficient and effectivestimulation, an impedance analyzer is provided for measuringelectrical impedance values indicative of a microelectrode-tissueinterface across a range of different frequencies.A preferred one of the measured electricalimpedance values is identified as being closest to a pureresistance. The neurological target can then be stimulatedat or near the frequency associated with the preferredimpedance value (peak resistance frequency), therebypromoting desirable traits, such as optimum chargetransfer, minimum signal distortion, increased stimulationefficiency, and prevention of microelectrode corrosion.The peak resistance frequency can be used to determinean preferred pulse shape. A target can be identifiedby microelectrode measurements of neuronal activityand/or impedance magnitude at peak resistance frequency.
