The present thesis investigated the impact of cognitive conflict on resources mobilization. We further assessed the shielding effect of volitional processes. Based on the Implicit-Affect-Primes-Effort model (Gendolla, 2012), we hypothesized that conflict-related negative affect should increase subjective task demand, and therefore moderate effort-related cardiovascular response. Furthermore, we predicted that both personal choice and action-orientation should shield individuals against the effect of conflict on effort. To do this, six experiments are reported. Results advocate for our predictions and further show that conflict primes are useful tools to assess the impact of the aversive nature of conflict on effort.