Poster F7, Tuesday, March 28, 8:00 – 10:00 am, Pacific Concourse
Alpha-Band Activity Tracks Updates to the Content of Spatial Working Memory
Eren Gunseli1, Joshua J. Foster1, David W. Sutterer1, Edward K. Vogel1, Edward Awh1; 1University of Chicago
Past work has established that the topography of alpha-band activity (8-12 Hz) tracks locations maintained in spatial working memory (WM). However, working memory is a flexible system in which representations can be updated to meet task demands. Here, we tested whether dynamic changes in alpha activity track updating of information in spatial WM. Subjects were shown a memory display for 250 ms that contained a colored circle inside one of five placeholders. After a retention interval of 500 ms an auditory cue instructed subjects to update the location held in memory. Following a second retention interval of 1500 ms participants used the mouse to click on the updated location. We used an inverted spatial encoding model to reconstruct the spatially-selective response profiles from the topographic distribution of alpha power. The location specificity of the estimated response profiles was quantified using a linear regression that approximates the slope of response profiles as a function of placeholder locations. Replicating previous findings, alpha-band activity successfully tracked the memory location during the initial retention interval. Importantly, it also tracked the transition to the updated location approximately 500 ms following the update cue during the second retention interval. Our results show that the topography of alpha-band activity tracks the content of an updated location in spatial working memory. These findings highlight a new approach for observing active updating of the contents of visual WM.
Topic Area: ATTENTION: Spatial