P.H. Schiller, E.J. Tehovnik and
V.S. Weiner, 2006
Vision Sci Soc Abstr., 404a,
Abstract
We examined the effects of electrical stimulation of area V1 in the monkey to
determine the feasibility of using implanted electrode arrays as a visual prosthesis.
Area V1 in the monkey is lissencephalic making for easy access; the visual field
is laid out topographically and the receptive fields of the neurons are quite
small. Our experiments show the following: 1. Low levels of electrical stimulation
reveal laminar specificity; when electrical stimulation is paired with a visual
target presented in the receptive field of the stimulated neurons, in the upper
layers target selection is interfered with whereas in the lower layers target
selection is facilitated. 2. Systematic variation of the placement of the visual
stimulus relative to the receptive field of the electrically stimulated neurons
reveals that the interference produced is local and affects only a small circular
area approximately the size of the receptive field of the stimulated neurons.
3. Examining the nature of the visual percept created with electrical stimulation
shows that stimulation for 80 milliseconds at 200 Hz between 20 and 120 microamps
applied to neurons with receptive fields at 2.5-3.5 degrees of eccentricity
produces an image that has a contrast of 6-12 percent and a size of 14-18 minutes
of visual angle in diameter.
We believe that the use of implanted electrode arrays has the potential of providing
visual information for the blind. We infer, furthermore, that successive activation
of electrodes will be able to provide motion information including motion parallax
for depth perception.
Supported by NEI NIH EY014884
Citation: Schiller, P. H., Tehovnik, E. J., & Weiner, V. S. (2006). Preliminary studies examining the feasibility of a visual prosthetic device: 2. The laminar specificity of electrical stimulation in monkey area V1 and the visual percepts created [Abstract]. Journal of Vision, 6(6):404, 404a, http://journalofvision.org/6/6/404/, doi:10.1167/6.6.404.