Ra. Normann et al., High-resolution spatio-temporal mapping of visual pathways using multi-electrode arrays, VISION RES, 41(10-11), 2001, pp. 1261-1275
The parallel processing of visual information was studied with penetrating
microelectrode arrays. We studied the high-resolution visuotopic organizati
on of cat primary visual cortex, and the encoding of simple visual stimuli
by ensembles of ganglion cells in the isolated turtle retina. The high-reso
lution visuotopic organization of visual cortex is non-conformal. Regions o
f visual cortex separated by 400 mu may have receptive field centers that a
re separated by as much as 3 degrees, or they may superimpose. Ganglion cel
ls are 'generalists', and are poor specifiers of the color of full field vi
sual stimuli. Groups of 'luminosity' type ganglion cells can assist in the
specification of stimulus color, but even individual 'chromatic' ganglion c
ells are not capable of quality color specification. These basic studies ha
ve relevance to the development of visual neuroprostheses based upon electr
ical stimulation of the retina and cortex. (C) 2001 Elsevier Science Ltd. A
ll rights reserved.