Abstract. -The phenomenon of stochastic resonance by which it is possible to boost the transduction of information by tuning into noise is experimentally and numerically contrasted with the phenomenon of resonant activation, i.e. the occurrence of a minimal, averaged residence time at an optimal time-scale in the presence of barrier modulations. The experimental system consists of a periodically modulated bistable colloidal Brownian dynamics. Interestingly enough, the two phenomena may occur simultaneously in the same system, although typically in quite different parameter regimes.