Visual working memory and long-term memory attentional control settings: Can we maintain both simultaneously?

Attentional control settings (ACSs) guide attention in our complex visual environments by determining both which stimuli capture our spatial attention, and which stimuli do not. For example, when searching for a blue shirt, other blue objects will capture attention, but red objects will not. Recent research indicates that humans can maintain a long-term memory (LTM) ACS for 4-30 complex visual objects. Additional recent research indicates that humans can maintain a visual working memory (VWM) ACS for one colour. The purpose of the current experiment was to determine whether it is possible to maintain both an LTM ACS and a VWM ACS simultaneously, such that both kinds of representations are capable of biasing visual spatial attention. Participants memorized and searched for 10 complex visual objects (i.e., the LTM ACS), and on each trial a random colour was presented that participants also memorized and searched for (i.e., the VWM ACS). While searching for the colour and objects, participants completed a modified Posner cueing task designed to measure spatial attentional capture. The results indicate that participants were able to adopt both a VWM ACS and an LTM ACS at the same time, as only cues that matched what participants were currently searching for were able to capture spatial attention. This experiment contributes two important findings: 1) it is possible to maintain both a VWM ACS and an LTM ACS simultaneous, such that both VWM and LTM representations can bias visual spatial attention, and 2) VWM and LTM ACSs operate independently using different resources; if they used the same attentional resources or the same memory resources, it would likely not be possible for both representations to bias visual spatial attentional capture simultaneously.