HRV modulates dorsomedial prefrontal cortex activity during emotionally enhanced memory-guided attention in a visual search task

Emotion, memory, and attention are closely interconnected, guiding cognitive processes and behavior. However, whether and how this complex interplay is modulated by the autonomic nervous system has been largely neglected to date. This study used functional MRI (fMRI) to investigate the relationship between heart rate variability (HRV) and brain function in healthy adults during an emotionally enhanced memory-guided visual search task. Participants engaged in a two-phase paradigm: during the encoding phase, they memorized the locations of targets embedded in emotional (positive or negative) or neutral images; during the retrieval phase, they identified low-contrast targets in previously viewed or novel images. High-frequency HRV (HF-HRV) was recorded at rest in the scanner during the anatomical image acquisition and subsequently correlated with the brain activation map derived from the interaction contrast of target memory and emotional context. Results revealed a positive correlation between HF-HRV and activation of the dorsomedial prefrontal cortex (dmPFC), a region implicated in emotional regulation and higher-order cognitive processes. These findings highlight the potential capacity of HRV to reflect the dmPFC's integration of emotional and cognitive processes to optimize memory-guided visual search performance.