Abstract
Attentional control settings (ACSs) guide attention in our complex visual environments by determining which stimuli capture spatial attention: When searching for something blue, 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 up to 30 complex visual objects, whereby only those objects capture attention when searched for (Giammarco et al., 2016, Visual Cognition). This behavioural research suggests that salient stimuli are rapidly compared to LTM ACS representations to assess whether a shift in attention is appropriate. Alternatively, this research might be explained by later effects on behaviour after the capture of attention. The purpose of the current experiment was to use electroencephalography to better understand the timing of attentional control offered by LTM ACSs. Participants memorized and searched for 30 complex visual objects in a modified Posner cueing task. In every target display, one object appeared to the left of fixation and one object appeared to the right. Participants indicated which was previously studied, inducing an ACS for the studied objects. Targets were preceded by cues at each location, one studied (ACS match) and one non-studied (ACS non-match). Similar to previous research, we observed a cueing effect; participants responded more quickly to the target if it appeared at the same location as the studied cue versus the non-studied cue. New for this study, some trials excluded target stimuli, so we could measure the cue-related N2pc as a measure of attentional selection. Consistent with rapid effects of LTM ACSs, we observed an N2pc contralateral to studied cues, with lateralized differences between studied and non-studied cues emerging within 160 ms post cue. These results provide direct evidence that our attentional goals represented in LTM can rapidly regulate which sensory stimuli do, and do not, capture out attention.