Abstract. To prevent forgetting in working memory, the attentional refreshing is supposed to increase the level of activation of memory traces by focusing attention. However, the involvement of memory traces reactivation in refreshing relies in the majority on indirect evidence. The aim of this study was to show that refreshing relies on the reactivation of memory traces by investigating how the reactivation of an irrelevant trace prevents the attentional refreshing to take place, and (2) the memory traces reactivated are sensorial in nature. We used a reactivated visual mask presented during the encoding (Experiment 1) and the refreshing (Experiment 2) of pictures in a complex span task. Results showed impaired serial recall performance in both experiments when the mask was reactivated compared to a control stimulus. Experiment 3 confirmed the refreshing account of these results. We proposed that refreshing relies on the reactivation of sensory memory traces.