Poster D119, Monday, March 26, 8:00-10:00 am, Exhibit Hall C
Pre-stimulus EEG oscillations reflect a preparatory form of episodic retrieval orientation
Mason Price1, Emmitt Wright1, Elizabeth Griffiths2, Jeffrey Johnson1; 1University of Missouri, 2University of Surrey
Studies from both experimental psychology and cognitive neuroscience have provided substantial evidence that successful episodic memory retrieval depends on the degree of overlap between a retrieval cue and the targeted memory trace. Recently, ERPs have been extensively used to investigate how changes in retrieval cue processing, or orientation, can bias retrieval in service of enhancing the likelihood of such overlap. While the evidence for retrieval orientation has thus far come exclusively from post-stimulus differences in ERP amplitude, whereby effects onset by approximately 300 ms after stimulus onset and are relatively sustained, the requirement of baseline correction for amplitude analyses potential limits the true magnitude of these effects as well as their detection under certain conditions. The current study resolved this issue by analyzing the pre-stimulus period immediately preceding retrieval cue onset to test for a preparatory form of retrieval orientation. Participants encoded a series of picture and words, and then completed separate memory test blocks in which only one stimulus class was targeted at a time. Multivariate pattern analysis (MVPA) of the pre-stimulus EEG oscillations indicated above-chance performance at identifying the targeted class of items. These retrieval orientation effects were relatively constant throughout the pre-stimulus period, providing further support for the notion that orienting constitutes sustained and preparatory cognitive states intended to meet the demands of episodic retrieval tasks.
Topic Area: LONG-TERM MEMORY: Episodic