Visual Cortex Responses to Single- and Simultaneous Multiple-Electrode Stimulation of the Retina: Implications for Retinal Prostheses

摘要: PURPOSE. The aim of this study was to compare simultaneous stimulation multiple electrodes single-electrode in a retinal prosthesis. METHODS. A platinum electrode array implanted into the suprachoroidal space six normally sighted anesthetized cats. Multiunit activity from primary visual cortex response recorded. Cortical thresholds, yield responses, dynamic ranges, and spread activation were measured for three modes stimulation: single electrode, half-row (six-electrode horizontal line), column (seven-electrode vertical line). RESULTS. Stimulation best half-rows columns found elicit with higher lower charge thresholds per compared electrodes. Dynamic ranges between similar. As expected, peak voltages than those Spread activation, determined by increase threshold distance retina site, be similar single- multiple-electrode but dependent on orientation. CONCLUSIONS. yield, equivalent observed may due current and/or neural summation within retina. Such techniques could useful presentation lines edges objects using stimulator low voltage compliance. Furthermore, results suggest that more complex processing strategies addition sequential individual should considered prostheses. (Invest Ophthalmol Vis Sci. 2012;53:6291–6300) DOI:10.1167/ iovs.12-9434