Visual working memory (VWM) is a subject of ongoing debate regarding whether multiple item representations can simultaneously guide attention. The Single Item Template hypothesis (SIT) posits that VWM representations only allow a single item to guide attention, while the Multiple Item Template hypothesis (MIT) suggests that multiple items in VWM representations can guide attention simultaneously. This study further investigates this through a dual-task paradigm. Participants were required to complete memory-search tasks under different memory and match types, with memory items and distractors being of the same category (Experiment 1) and different categories (Experiment 2). Results show: (1) In Experiment 1, when the memory type was color, multiple item representations in VWM simultaneously guided attention, providing support for the MIT hypothesis
however, when the memory type was graphic, multiple item representations in VWM did not simultaneously guide attention, providing support for the SIT hypothesis. (2) In Experiment 2, whether the memory type was color or graphic, multiple item representations in VWM did not simultaneously guide attention, providing support for the SIT hypothesis. Whether multiple item representations in VWM can simultaneously guide attention is significantly influenced by memory types and the relationship between memory items and categories of distractors.