  An artificial microswimmer drifts in response to spatio-temporal modulations
of an activating suspension medium. We consider two competing mechanisms
capable of influencing its tactic response: angular fluctuations, which help it
explore its surroundings and thus diffuse faster toward more active regions,
and self-polarization, a mechanism inherent to self-propulsion, which tends to
orient the swimmer's velocity parallel or antiparallel to the local activation
gradients. We investigate, both numerically and analytically, the combined
action of such two mechanisms. By determining their relative magnitude, we
characterize the selective transport of artificial microswimmers in
inhomogeneous activating media.
