Refreshing boosts memory but does not protect it against interference

Attention can be directed to representations maintained in working memory, increasing their accessibility for later retrieval. Previous studies have observed a cumulative benefit of focused attention: The more often an item is brought into the focus of attention, the better it is recalled. This can be explained by the notion that a memory representation is strengthened every time attention is focused on it, a process known as refreshing. The current study investigated whether refreshing goes together with increased robustness against interference. In two experiments, we examined whether an item's susceptibility to interference by an interruption task gradually decreases as an item is more frequently refreshed. Participants memorized six colors for a continuous reproduction test. During the retention interval, they were instructed to refresh some of these colors once, twice, or never, and then completed an interruption task in half of the trials. In Experiment 1, the interruption was a domain-non-overlapping auditory parity judgment task, whereas in Experiment 2, we used a domain-overlapping visual color judgment task. In both experiments, memory performance was hindered by the interruption but improved with increasing refreshing frequency. These two effects did not interact, indicating that the negative impact of the interruption was not reduced by refreshing. Thus, although refreshing an item improves retrieval from working memory, it does not provide greater protection against interference.