Poster F89, Tuesday, March 28, 8:00 – 10:00 am, Pacific Concourse
The anterior prefrontal cortex and the hippocampus are negatively correlated during false memories
Brittany M. Jeye1, Jessica M. Karanian1, Scott D. Slotnick1; 1Boston College
False memories have been associated with activity in the anterior/dorsolateral prefrontal cortex (A/DLPFC) and the hippocampus. These regions are assumed to work in concert during false memories, which would predict a positive correlation between the magnitudes of activity in these regions across participants. However, the A/DLPFC may also inhibit the hippocampus (e.g., during retrieval-induced forgetting). If this occurred during false memories, it would predict a negative correlation between the magnitudes of activity in these regions. In the present fMRI study, we aimed to distinguish between these hypotheses. During encoding, participants viewed abstract shapes in the left or right visual field. During retrieval, old shapes were presented and participants classified each shape as previously in the “left” or “right” visual field followed by an “unsure”–“sure”–“very sure” confidence rating. The contrast of left-hits and left-misses produced two activations in the hippocampus and three activations in the A/DLPFC, which served as regions of interest for the correlation analysis. For each participant, activity associated with false memories (i.e., right-“left”-“very sure” responses) from the two hippocampal regions were plotted as a function of activity in each A/DLPFC region. Across participants, for one region of the anterior prefrontal cortex (APFC), there was a negative correlation between the magnitude of activity in the hippocampus and the magnitude of activity in this region (p < .05, Bonferroni corrected for multiple comparisons). This suggests that the APFC can inhibit the hippocampus during false memories and that participants engage either the APFC or the hippocampus during false memories.
Topic Area: LONG-TERM MEMORY: Episodic