This second volume of the "Nervous System and Electric Currents" represents the collected papers of the Proceedings of the fourth annual national conference, organised by the Neuro-Electric Society. It will be held at the Convention Center, San Antonio, Texas,March 10-12, 1971. The interests of the Neuro-Electric Society focus upon the measurement and quantification of neuro-electric phenomena, neuro stimulation and recording techniques and procedures, and the appli cations of biomedical engineering to the furthering of our under standing about neural-behavioral processes. These research papers further explore the influence of electrical currents on the neurophysiological correlates of the nervous system. The "central" nervous system is still the main focus of research. The use of transcranially applied electric currents in the production of electro-sleep and electro-anesthesia is the important practical clinical aspect of these interesting researches. However, a net., emphasis is now also beginning to be placed on the effects of these applied currents to the "peripheral" nervous system. The Editors wish to thank the following sponsors: Office of Naval Research, Washington, D.C. (Grant No. NR 108-918); Medtronic Inc., Ninneapolis, Hinnesota; and Plenum Press, New York, New York. We also wish to thank for their cooperation the Association for the Advancement of Hedical Instrumentation, Bethesda, 1'laryland, the In stitute of Electrical and Electronic Engineers (Group of Engineering in Hedicine and Biology), New York, New York, and the International Society for Electro-sleep and Electro-Anesthesia, Graz, Austria.