1. A method of treating a patient suffering from chronic pain and/or generalized seizures, said method comprising: selecting a patient suffering from chronic pain and/or generalized seizures; applying electrical stimulation to at least a portion of the patient's subcortical structures involved in the generation and control of generalized efference copy signals under conditions effective to treat the patient's chronic pain and/or generalized seizures; detecting generalized efference copy signals of the patient; and controlling said applying electrical stimulation in response to detected generalized efference copy signals of the patient.