AbstractWe introduce wire length as a salient complexity measure for analyzing the circuit complexity of sensory processing in biological neural systems. This new complexity measure is applied in this paper to two basic computational problems that arise in translation- and scale-invariant pattern recognition, and hence appear to be useful as benchmark problems for sensory processing. We present new circuit design strategies for these benchmark problems that can be implemented within realistic complexity bounds, in particular with linear or almost linear wire length. Finally, we derive some general bounds which provide information about the relationship between new complexity measure wire length and traditional circuit complexity measures.