A core function of working memory (WM) involves attuning to task-relevant information and encoding this information, but it is also crucial for task-irrelevant information to be appropriately ignored. This study sought to determine how individuals’ ability to upregulate or downregulate visual activity during a WM task was impacted when their resources became more limited, such as when they are partially occupied by a non-visual working memory task. The study was conducted with 17 volunteers, aged 18-27, and used fMRI to measure the role of domain-general WM resources in the top-down attentional modulation of task-relevant and irrelevant visual representations. Testing involved a dual-task paradigm, where each trial began with an auditory presentation of either a high-load or low-load sequence of numbers to remember. A combination of relevant (e.g., images of faces) and irrelevant images were presented across a 7-second time span, and participants were asked to recall the relevant images and digits. Findings demonstrated that when participants were taxed by high-load memory tasks, they struggled to actively ignore the irrelevant information. These results suggest that when a heavier load is placed on working memory resources, one’s ability to filter out distracting information becomes impaired.