A neural interface for a cortical vision prosthesis

The development of a cortically based vision prosthesis has been hampered b y a lack of basic experiments on phosphene psychophysics. This basic resear ch has been hampered by the lack of a means to safely stimulate large numbe rs of cortical neurons. Recently, a number of laboratories have developed a rrays of silicon microelectrodes that could enable such basic studies on ph osphene psychophysics. This paper describes one such array, the Utah electr ode array, and summarizes neurosurgical, physiological and histological exp eriments that suggest that such an array could be implanted safely in visua l cortex. We also summarize a series of chronic behavioral experiments that show that modest levels of electrical currents passed into cortex via this array can evoke sensory percepts. Pending the successful outcome of biocom patibility studies using such arrays, high count arrays of penetrating micr oelectrodes similar to this design could provide a useful tool for studies of the psychophysics of phosphene perception in human volunteers. Such stud ies could provide a proof-of-concept for cortically based artificial vision . (C) 1999 Published by Elsevier Science Ltd. All rights reserved.