Baiwei Liu¹ (), Freek van Ede¹; ¹Vrije Universiteit Amsterdam

When searching for objects, we continuously navigate between internal search goals held in memory and the external sensory world containing the objects we search. Yet, little remains known about the dynamic processes by which internal and external search processes combine to support efficient search. One key open question is whether internal and external search operations necessarily take turns (completing selection of the relevant search goal before searching it) or can proceed concurrently (guiding search from the moment the process of search-goal selection is initiated). To address this, we studied the dynamics that govern internal search-goal and external target selection during working-memory guided search. Participants held two potential search goals in visual working memory and were cued to find one of them in a search display that was presented simultaneously with the memory cue. To isolate internal and external selection, we independently varied the location of the memorised internal search goal and the to-be-found external visual target. We then leveraged spatial modulations in gaze and EEG activity to track the dynamics of internal (search-goal) and external (target) selection through time. Our findings reveal how internal and external selection during working-memory guided search do not necessarily take turns, but can proceed concurrently. This provides unprecedented insight into how internal and external visual operations combine to yield efficient search.

Acknowledgements: This work was supported by an ERC Starting Grant from the European Research Council (MEMTICIPATION, 850636) and an NWO Vidi Grant from the Dutch Research Council (14721) to F.v.E.