  We study how a coupled array of spiking chaotic systems synchronizes to an
external driving in a short time. Synchronization means spike separation at
adjacent sites much shorter than the average inter-spike interval; a local lack
of synchronization is called a defect. The system displays sudden spontaneous
defect disappearance at a critical coupling strength. Below critical coupling,
the system reaches order at a definite amplitude of an external input; this
order persists for a fixed time slot. Thus, the array behaves as an excitable
system, even though the single element lacks such a property. The above
features provide a dynamical explanation of feature binding in perceptual
tasks.
