  The universality class of the avalanche behavior in plastically deforming
crystalline and amorphous systems has been commonly discussed, despite the fact
that the microscopic defect character in each of these systems is different. In
contrast to amorphous systems, crystalline flow stress increases dramatically
at high strains and/or loading rates. We perform simulations of a
two-dimensional discrete dislocation dynamics model that minimally captures the
phenomenology of nanocrystalline deformation. In the context of this model, we
demonstrate that a classic rate-dependence of dislocation plasticity at large
rates (> 1000/s), fundamentally controls the system's statistical character as
it competes with dislocation nucleation: At large rates, the behavior is
statistically dominated by long-range correlations of "dragged" mobile
dislocations. At small rates, plasticity localization dominates in small
volumes and a spatial integration of avalanche behaviors takes place.
