Introduction THIS is basically a case report on long-term direct electrical stimulation of the auditory nerve in man. The report is supplemented by some historical facts, and by selected comments on electrophysiology, physical chemistry, and perceptual psychology. These comments are sometimes injected between segments of experimental observations and thereby tend to favor one interpretation of the data over others. To counterbalance that trend it was elected to describe as many observations as possible, even though some may seem redundant and others incomplete. This sometimes makes dull reading, but I hope it also makes this report as free from experimenter bias as can be achieved. The study was initially designed to answer questions raised by our own previous experience with electrical stimulation and by the writings of others. We especially planned to study two aspects of perception: (1) the resolution obtainable by discrete stimulation of several small populations of auditory nerve

Electrical Stimulation of the Auditory Nerve in Man

Electrical stimulation of neural tissue to evoke behavioral responses

Electrical stimulation of the nervous system is of increasing importance for a variety of prospective neural prostheses. Electrochemical reactions which may occur at Pt or other noble metal-tissue interfaces are reviewed. Use of stimulus waveforms with a net direct current component increases the probability of tissue damage. There are three conceptually safe methods of injecting charge from a noble metal into tissue: modification of the electrical double layer at the interface and coupling via either of two symmetrical surface-layer oxidation-reduction processes. These reactions may be addressed with stimulus waveforms without a direct current component and with controlled charge densities.

Electrochemical Considerations for Safe Electrical Stimulation of the Nervous System with Platinum Electrodes

THE PRESENT WORK is part of a more general investigation into neuro-physiological activities of the cerebral cortex which may be involved in the elaboration or mediation of conscious sensation. The primary concern in these studies is the dynamics of the processes involved, rather than their topographical representation.

T. G. Bidder

Papers

The production of brain lesions with electric currents. II. Bidirectional currents.