Cortical maps reflect a precise topographic neuronal organization where neighboring sites of maximum relative activity on the cortical plane correspond to nearby points in parameter space. Because in such cortical structures signal processing relies entirely on patterns of connectivity, cortical maps have been suggested to be computationally efficient. This fact is supported by recent quantitative studies performed in topographically organized primate visual areas, that is in Vl, in the inferotemporal (IT) cortex, and in the superior temporal sulcus (STS), where cells discriminate different complex visual stimuli within 5 to 10 ms. Because firing rate has been shown to be rarely in excess of 1 spike in a 5-10 ms period in cortex, one of the key question is whether cortical maps can operate on the basis of single spikes in multiple input sources.