Visual resolution with retinal implants estimated from recordings in cat visual cortex.
We investigated cortical responses to electrical stimulation of the retina using epi- and sub-retinal electrodes of 20-100 microm diameter. Temporal and spatial resolutions were assessed by recordings from the visual cortex with arrays of microelectrodes and optical imaging. The estimated resolutions were approximately 40 ms and approximately 1 degrees of visual angle. This temporal resolution of 25 frames per second and spatial resolution of about 0.8 cm at about 1m and correspondingly 8 cm at 10 m distance seems sufficient for useful object recognition and visuo-motor behavior in many in- and out-door situations of daily life.
Eckhorn
Reinhard
R
Department of Physics, Neurophysics Group, Philipps-University Marburg, and University Eye Hospital, Medical Faculty University of Tübingen, Germany. eckhorn@staff.uni-marburg.de
Wilms
Marcus
M
Schanze
Thomas
T
Eger
Marcus
M
Hesse
Lutz
L
Eysel
Ulf T
UT
Kisvárday
Zoltán F
ZF
Zrenner
Eberhart
E
Gekeler
Florian
F
Schwahn
Helmut
H
Shinoda
Keisuke
K
Sachs
Helmut
H
Walter
Peter
P
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002415:Cats; D004599:Electric Stimulation Therapy / Q000379:methods*; D004567:Electrodes, Implanted; D008839:Microelectrodes; D010719:Phosphenes / Q000502:physiology; D019736:Prostheses and Implants; D012160:Retina / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*