A system for mapping a high resolution image to a lower resolution electrode array by applying varying stimulus to neighbouring electrodes (12,14) to create a perceived image greater in resolution than the electrode array. By applying the sub-threshold stimulus to two neighbouring electrodes (12,14) 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 neighbouring electrodes (12,14), the location of the stimulus can be altered. Further, noise can be applied to the stimulating electrode or its neighbouring electrodes to reduce the threshold of stimulation.
