Poster Session D, Monday, March 25, 8:00 – 10:00 am, Pacific Concourse
Characterizing the timecourse and mechanisms of the attentional selection of object representations in working memory
Charlie Giattino1, Saikiran Gudla2, Mariana Feingold1, Marty Woldorff1; 1Duke University, 2University of Cincinnati
Attention can be directed externally to spatial locations, features, and objects in the environment, as well as internally to representations such as those in working memory (WM). Much recent work has focused on understanding the nature of such internal attention; yet, many of these studies have focused on attention to spatial locations or simple objects, rather than complex objects such as faces and scenes (e.g., houses). We sought to further characterize the timecourse and nature of internal object attention by recording EEG as subjects performed three different tasks designed to allow comparison of object-selective processing at multiple levels. To make these comparisons, we took advantage of EEG measures of object-selective processing, primarily the face-selective N170 ERP effect and its distinct scalp topography. We previously presented our findings using attentive object viewing (Task 1) to elucidate the timecourse of selective attention to external objects (Task 2). Here we focused on using both external attention tasks as object-selective templates to further characterize selective attention to, and WM maintenance of, internal object representations (Task 3). In Task 3, we used a delayed match-to-sample task with two samples on each trial, a face and a house, one of which was retroactively cued as relevant for that trial. We found that retro-cueing attention in this way led to a pattern of voltages highly similar to the external object attention tasks, starting at ~400 ms post-cue and lasting for several hundred milliseconds, giving insight into the timecourse of directing internal attention to the contents of WM.
Topic Area: ATTENTION: Nonspatial