Schedule of Events | Symposia

Neural activities in left angular gyrus and the hippocampus are predictive of memory precision

Poster Session C - Sunday, March 30, 2025, 5:00 – 7:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Mingzhu Hou¹ (mingzhu.hou@utdallas.edu), Luke R. Pezanko¹, Ayse N. Z. Aktas¹, Paul F. Hill², Arne D. Ekstrom², Michael D. Rugg¹; ¹Center for Vital Longevity, The University of Texas at Dallas, ²Department of Psychology, The University of Arizona

Prior fMRI studies examining the neural mechanisms of retrieval success and precision have reported inconsistent results. Here, we examined the neural correlates of success and precision with a memory task that assessed precision for spatial location. In two studies that employed similar experimental procedures, 47 healthy young adults (mean age 23 yrs, 24 female) underwent functional magnetic resonance imaging scanning during a single study–test cycle. At study, participants viewed a series of object images, each placed at a randomly selected location on an imaginary circle. At test, studied images were intermixed with new images and presented to the participants. The requirement was to move a cursor to the location of the studied image, guessing if necessary. Participants then signaled whether the presented image had been studied. Memory precision was quantified as the angular difference between the studied location and the location selected by the participant. Across experiments, a precision effect was evident in the left angular gyrus (AG), where BOLD activity covaried with location accuracy. In addition, multivoxel pattern analysis revealed a significant item-level reinstatement effect in the angular gyrus for high-precision trials. The reinstatement effect was stronger for high- than for low-precision judgments. Linear mixed regression analyses revealed that BOLD activity in both AG and the hippocampus was predictive of trial-wise memory precision. There was no evidence of a retrieval success effect in either region. These findings are partially consistent with prior evidence that success and precision are dissociable features of memory retrieval.

Topic Area: LONG-TERM MEMORY: Episodic