Poster D84, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Interactions between parietal and striatal systems contribute to subjective recollection and decision-making
Yana Fandakova1, Elliott Johnson1, Simona Ghetti1; 1University of California Davis
Vivid recollections may provide a stronger basis for action than weaker memories, but they also tend to be more accurate, making it difficult to establish if the experience of recollection in itself guides decision-making. We experimentally dissociated subjective recollection from accuracy to characterize their unique neural underpinnings and implications for decision-making. During scanning, participants (N = 29) performed two-alternative forced-choice recognition across two conditions: in the Target-Match condition, the distracter was a novel exemplar of a studied item (e.g., studied vs. unstudied chair); in the Other-Match condition, the distracter was a novel exemplar of a different studied, but untested item (i.e., studied chair vs. unstudied version of a toaster). While memory accuracy was higher in the Target-Match condition, t(28)=5.64, p<.05, subjective recollection reports were higher in the Other-Match condition, t(28)=8.04, p<.05, demonstrating a dissociation between accuracy and subjective recollection. Notably, on indepedent trials, participants bet on the accuracy of their memory more frequently for Other-Match trials, t(28)=6.47, p<.05. Hippocampal activity was higher for correctly than incorrectly remembered trials irrespective of condition, whereas Other-Match trials showed enhanced activity in the precuneus and the retrosplenial cortex compared to Target-Match trials. Decisions to bet on memory were associated with increased activity in the dorsal striatum. Increased connectivity of precuneus and retrosplenial cortex with striatum during Other-Match trials predicted greater subjective recollection, r=.50, p<.05 and higher betting frequency, r=.48, p<.05 in this condition. These results suggest that these parietal regions support subjective recollection and, together with the striatum, contribute to decision-making and memory regulation.
Topic Area: LONG-TERM MEMORY: Episodic