  We study the behavior of the AsqTad quark propagator in Landau gauge on
quenched SU(2) gauge configurations under the removal of center vortices. In
contrast to recent results in SU(3), we clearly see the infrared enhancement of
the mass function disappear if center vortices are removed, a sign of the
intimate relation between center vortices and chiral symmetry breaking in SU(2)
gauge-field theory. These results provide a benchmark with which to interpret
the SU(3) results. In addition, we consider vortex-only configurations. On
those, the quark dressing function behaves roughly as on the full
configurations, and the mass function picks up an almost linear momentum
dependence.
