Situated in the wider framework of frame semantics, the paper employs an experimental approach involving a reaction time study to test the activation of semantic frames via semantic priming. Experiment 1 deals with the frame of journey and employs a lexical decision task in a reaction time paradigm, while Experiment 2 deals with the frame of conflict and uses a categorization task, also in a reaction time paradigm. Both experiments were designed in Open Sesame. Target stimuli were in Serbian, selected through a norming procedure involving prototypicality ratings on Likert scales. Additionally, identical filler items were included in both experiments. Priming was performed using lexical materials modified to facilitate the activation of the respective frames. The obtained results showed that there was no facilitation in the experimental group in Experiment 1 compared to the control group; however, in Experiment 2, we were able to identify facilitation in the experimental group in the main task, licensed by the initial priming. These results suggest that the lexical decision task has a reduced cognitive load compared to the categorization task, thereby overriding the priming condition. In effect, categorization task appears to be a more suitable procedure for testing semantic frame activation.