We have developed a three-dimensional silicon electrode array which pr
ovides 100 separate channels for neural recording in cortex. The devic
e is manufactured using silicon micromachining techniques, and we have
conducted acute recording experiments in cat striate cortex to evalua
te the recording capabilities of the array. In a series of five acute
experiments, 58.6% of the electrodes in the array were found to be cap
able of recording visually evoked responses. In the most recent acute
study, the average signal-to-noise ratio for recordings obtained from
56 of the electrodes in the array was calculated to be 5.5:1, Using st
andard window discrimination techniques, an average of 3.4 separable s
pikes were identified for each of these electrodes. In order to compar
e the two-dimensional mapping capabilities of the array with those der
ived from other technologies, orientation preference and ocular domina
nce maps were generated for each of the evoked responses. Histological
evaluation of the implant site indicates some localized tissue insult
, but this is likely due to the perfusion procedure since high signal-
to-noise ratio neural responses were recorded. The recording capabilit
ies of the Utah Intracortical Electrode Array in combination with the
large number of electrodes available for recording make the array a to
ol well suited for investigations into the parallel processing mechani
sms in cortex.