Mesolimbic contribution to objective and subjective memory retrieval success

Poster Session E - Monday, March 9, 2026, 2:30 – 4:30 pm PDT, Fairview/Kitsilano Ballrooms

Yifang Liu¹ (yifangl@uoregon.edu), Ian C. Ballard², J. Benjamin Hutchinson¹, John Clithero¹, Vishnu P. Murty¹; ¹University of Oregon, ²University of California, Riverside

Prior work shows that successfully retrieving information is intrinsically rewarding and engages regions within the mesolimbic dopamine system, including the ventral tegmental area (VTA) and nucleus accumbens (NAcc). However, it remains unclear whether these regions differentially track objective retrieval success (accuracy) versus subjective retrieval success (beliefs about memory performance). To address this question, we leverage the high-resolution Natural Scenes Dataset (NSD), in which eight participants completed thousands of continuous recognition trials while undergoing fMRI. Participants judged whether each image had been seen before, allowing us to dissociate objective and subjective retrieval outcomes by comparing hits versus false alarms, respectively. We examined mesolimbic responses to these retrieval signals and found that VTA activity was elevated when participants believed they had successfully recognized an image as familiar (hits and false alarms), whereas NAcc activity increased selectively for accurate recognition (hits only), suggesting partially dissociable roles in evaluating memory outcomes. We further assessed functional connectivity between the hippocampus and mesolimbic regions and observed that NAcc–CA1 connectivity differentiates hits from false alarms; whereas all other connections between the VTA or NAcc and hippocampal subfields (CA1, CA2/3, and dentate gyrus) did not, indicating a system-level distinction in the VTA and NAcc’s interactions with hippocampus. We are currently applying drift-diffusion modeling to further link these neural dissociations to latent decision parameters underlying recognition judgments. Together, these results highlight complementary contributions of mesolimbic regions to memory retrieval success and provide a framework for relating neural reward signals to decision processes during memory-guided judgments.

Topic Area: LONG-TERM MEMORY: Episodic