Stereotactic electrode assembly

A neural prosthetic device for an auditory cortex of a patient has a support arranged in the auditory cortex with a plurality of electrical contacts and is connected to a speech processor for receiving and processing audio information and outputting processed electrical signals. Each of the plurality of electrical contacts independently outputs electrical discharges in accordance with the processed electrical signals. The plurality of electrical contacts are arranged to approximately tonotopically match the auditory cortex.And, methods and apparatus for selectively treating or inactivating neurons within the brain of a patient. The apparatus includes a dual purpose multicontact neuron-monitoring electrode assembly and an introducer tube for introducing the electrode assembly within a patient in the vicinity of the target tissue. The apparatus and methods of the instant invention are particularly suited to performing magnetic pallidotomy for the treatment of Parkinson's disease.