Sage Bendickson (), Nicholas Schmitz, David Sutterer; ¹University of Tennessee Knoxville

Space and time are proposed to play a critical role in working memory (WM) formation and maintenance relative to other object features (Schneegans & Bays, 2017). Alongside perspectives that WM relies on space, recent work has found that stimulus position holds a prioritized status in WM (Rajsic & Wilson, 2014) and that alpha-band EEG activity spontaneously carries information about the location of a stimulus when its location is task- irrelevant (Foster et al., 2017). Recent work also finds that observers make microsaccades towards the encoded hemifield of to-be-remembered items during the maintenance of non-spatial features even when objects are tested based on ordinal position (de Vries et al., 2023), suggesting that space maintains its prioritized role even when temporal information can be used to individuate objects. However, an open question is whether neural representations of object’s precise location are maintained throughout a memory delay when items can be individuated by their ordinal position. To answer this question, we used a sequential two-item delayed color estimation task in which each stimulus presentation was followed by a 1- second delay. Observers were cued to report the color of one of the two circles based on its ordinal position (first or second). This ensured that the objects could be individuated without relying on location. We applied an Inverted Encoding Model (IEM) to the topography of EEG alpha-band power to measure the spatial representation of each item in the sequence. Consistent with past work, we found a robust representation of each item’s location during the delay immediately following encoding, and the spatial representation of item one did not sustain following the presentation of the second item. As such, our results indicate that spatial locations are spontaneously maintained after initial encoding but can be discarded following the presentation of new information.