Poster A78, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
EEG oscillations and value-based recognition memory
Blake Elliott1, Chris Blais1, Gene Brewer1; 1Arizona State University
The ability to selectively encode important or valuable information is an essential aspect of human memory. However, the temporal processes underlying how value can affect memory is not yet well understood. In the present research we examined behavioral and neurophysiological correlates of value-based memory encoding. Participants were asked to encode words in multiple study phases that were randomly paired with high or low point values. They were instructed to maximize their score on a subsequent word recognition test by successfully remembering as many words as possible. Subjective states of recollection (i.e., “Remember”) and familiarity (i.e., “Know”) were assessed at retrieval. High value words were discriminated more effectively than low value words and this difference was primarily driven by increases in Remember responses with no difference in Know responses (p < .001). We then examined EEG oscillatory signals from the encoding period as a function of whether subjects subsequently recognized the item. We found decreased theta power during the first 0-1000 ms post-stimulus followed by increased high-frequency gamma power from 1000-2000 ms for subsequently recollected high value words compared to low value words. Overall, the behavioral and neurophysiological data suggests that value directed encoding results in a greater effect on subjective states of recollection, and that higher valued recollected responses can be dissociated from lower valued responses at encoding using time-frequency analysis.
Topic Area: LONG-TERM MEMORY: Episodic