  We characterize the synchronization of an array of coupled chaotic elements
as a phase transition where order parameters related to the joint probability
at two sites obey power laws versus the mutual coupling strength; the phase
transition corresponds to a change in the exponent of the power law. Since
these studies are motivated by the behaviour of the cortical neurons in
cognitive tasks, we account for the short time available to any brain decision
by studying how the mutual coupling affects the transient behaviour of a
synchronization transition over a fixed time interval. We present a novel
feature, namely, the absence of decay of the initial defect density for small
coupling.
