@article{TEXTUAL,
      recid = {6297},
      author = {Sutterer, David W. and Joshua J. Foster and Adam, Kirsten  C. S. and Vogel, Edward K. and Awh, Edward},
      title = {Item-specific delay activity demonstrates concurrent  storage of multiple active neural representations in  working memory},
      journal = {PLOS Biology},
      address = {2019-04-26},
      number = {TEXTUAL},
      abstract = {Persistent neural activity that encodes online mental  representations plays a central role in working memory  (WM). However, there has been debate regarding the number  of items that can be concurrently represented in this  active neural state, which is often called the “focus of  attention.” Some models propose a strict single-item limit,  such that just 1 item can be neurally active at once while  other items are relegated to an activity-silent state.  Although past studies have decoded multiple items stored in  WM, these studies cannot rule out a switching account in  which only a single item is actively represented at a time.  Here, we directly tested whether multiple representations  can be held concurrently in an active state. We tracked  spatial representations in WM using alpha-band (8–12 Hz)  activity, which encodes spatial positions held in WM. Human  observers remembered 1 or 2 positions over a short delay  while we recorded electroencephalography (EEG) data. Using  a spatial encoding model, we reconstructed active  stimulus-specific representations (channel-tuning functions  [CTFs]) from the scalp distribution of alpha-band power.  Consistent with past work, we found that the selectivity of  spatial CTFs was lower when 2 items were stored than when 1  item was stored. Critically, data-driven simulations  revealed that the selectivity of spatial representations in  the two-item condition could not be explained by models  that propose that only a single item can exist in an active  state at once. Thus, our findings demonstrate that multiple  items can be concurrently represented in an active neural  state.},
      url = {http://knowledge.uchicago.edu/record/6297},
}