  We study the differences between the process of decoherence induced by
chaotic and regular environments. For this we analyze a family of simple models
wich contain both regular and chaotic environments. In all cases the system of
interest is a "quantum walker", i.e. a quantum particle that can move on a
lattice with a finite number of sites. The walker interacts with an environment
wich has a D dimensional Hilbert space. The results we obtain suggest that
regular and chaotic environments are not distinguishable from each other in a
(short) timescale t*, wich scales with the dimensionality of the environment as
t*~log(D). Howeber, chaotic environments continue to be effective over
exponentially longer timescales while regular environments tend to reach
saturation much sooner. We present both numerical and analytical results
supporting this conclusion. The family of chaotic evolutions we consider
includes the so-called quantum multi-baker-map as a particular case.
