  The sequence of deformation bursts during plastic deformation exhibits
scale-free features. In addition to the burst or avalanche sizes and the rate
of avalanches the process is characterized by correlations in the series which
become manifest in the resulting shape of the stress-strain curve. We analyze
such features of plastic deformation with 2D and 3D simulations of discrete
dislocation dynamics models and we show, that only with severe plastic
deformation the ensuing memory effects become negligible. The role of past
deformation history and dislocation pinning by disorder are studied. In
general, the correlations have the effect of reducing the scatter of the
individual stress-strain curves around the mean one.
