Poster A74, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Patterns of Alpha-band Oscillations Track Spatial Long Term Memory Performance
David Sutterer1, Joshua Foster1, John Serences2, Edward Vogel1, Edward Awh1; 1University of Chicago, 2University of California - San Diego
Recent work has demonstrated that it is possible to reconstruct spatially-specific channel tuning functions (CTFs) during the encoding and delay period of a working memory (WM) task, and during the retrieval period of a long term memory (LTM) task, using an inverted encoding model (IEM) and electroencephalography (EEG). Specifically, these CTFs can be derived from the distribution of alpha-band (8-12hz) activity across the scalp, providing a temporally resolved measure of both the location stored in WM as well as the locations retrieved from LTM. Here we show that the pattern of alpha-band activity across the scalp tracked participants’ memory performance as they learned object-position associations over the course of the experiment. Participants learned randomly assigned positions for a collection of 80 unique shapes, with the position selected from a continuous 360 degree space around a circle. Immediately following encoding, participants were presented with shape cues and asked to retrieve the associated position. Participants repeated the encoding and retrieval process for the to-be-remembered object position pairings 9 times over the course of the session. We found that the spatial selectivity of alpha-band activity tracked subjects’ memory performance as learning progressed and when trials were sorted based on the degree of response error. Thus, the topography of alpha band power may serve as a useful assay of spatial memory retrieval that can be acquired without an overt behavioral response.
Topic Area: LONG-TERM MEMORY: Episodic