The Role of the Left DLPFC and VLPFC in Positive and Negative Emotional Memory: An rTMS Study

Poster Session D - Monday, March 31, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Sandry M Garcia¹, Preston Thakral², Elizabeth A Kensinger¹; ¹Boston College, ²Smith College

Studies using repetitive transcranial magnetic stimulation (rTMS) have suggested a causal role of the left dorsolateral (DLPFC) and left ventrolateral (VLPFC) prefrontal cortices in positive and negative memory, respectively. We tested this valence-specificity by stimulating both regions in the same participants, and testing emotional and non-emotional memory within the same task. 26 young adults underwent 10-min 1Hz rTMS sessions on separate days, once over DLPFC and once over VLPFC. Immediately after rTMS, participants viewed positive, negative, and neutral nouns and decided whether they were abstract or concrete. Two versions of the encoding task varied presentation duration (1.5-sec or 3-sec per word). Group 1 had the short-presentation duration paired with DLPFC and the long-presentation duration with VLPFC; Group 2 had the opposite pairing. 30-mins after encoding, participants completed a recall and a recognition task. For recall, an ANOVA with PFC (DLPFC, VLPFC), Group (1, 2) and Valence (Negative, Positive, Neutral) revealed a PFC X Valence interaction [F(2, 48) = 4.953, p = .011]; DLPFC (but not VLPFC) rTMS led to a decrease in positive relative to negative recall (p = .02). With recognition, a 3-way interaction [F(2,48) = 8.833, p <.001] revealed that only Group 1 had a PFC X Valence interaction [F(2, 24) = 10.669, p <.001], driven by VLPFC rTMS leading to lower neutral recognition than DLPFC (p = .011). While the recall results partially support the role of the DLPFC in positive memory, the recognition results reveal a more complex picture and suggest a role of presentation duration.

Topic Area: EMOTION & SOCIAL: Emotion-cognition interactions