1. An apparatus configured to transmit a signal to a vertebrate nervous system, the apparatus comprising: a processor configured to receive an input signal representative of at least a portion of a visual frame; an encoder configured to encode the input signal into a plurality of pulses; and a plurality of stimulating electrodes; wherein: at least a subset of the plurality of pulses is configured in a polychronous pattern comprising at least two non-synchronous pulses; information related to at least the portion of the visual frame is encoded into the polychronous pattern; the polychronous pattern is characterized by a group delay that is common to all pulses within the plurality of pulses, the group delay being determined by a spatiotemporal filter applied to the input signal; and the polychronous pattern is adapted for transmission via a plurality of electrodes operably coupled to the nervous system.