The present invention is a system for mapping a high resolution image to a
lower resolution electrode array and, by applying varying stimulus to
neighboring electrodes, creating a perceived image greater in resolution
than the electrode array. The invention is applicable to a wide range of
neural stimulation devices including artificial vision and artificial
hearing. By applying a sub-threshold stimulus to two neighboring
electrodes where the sum of the stimuli is above the threshold of
perception, a perception is created in neural tissue between the two
electrodes. By adjusting the stimulus on neighboring electrodes, the
location of stimulation can be altered. Further, noise can be applied to
the stimulating electrode or its neighboring electrodes to reduce the
threshold of stimulation.