“Follow your heart”: Heart-to-Brain-driven interplay relates to self-congruency.

When emotions, thoughts, and actions align, this is referred to as “self-congruency”. Therefore, this study aimed to determine how temporal covariance of the heart and brain signals were related to self-congruency. Thirty-eight healthy adults underwent functional magnetic resonance imaging to obtain neural markers of variability, whereas heart rate variability (HRV) was measured using photoplethysmography. Participants were also asked to report their level of self-congruency with a graphic rating scale. A cross-covariance analysis (CCA) was performed to assess the temporal covariance of signals arising from both organs, which was then correlated with self-congruency scores. Overall, the CCA results revealed brain-to-heart-driven interplay in brain regions involved in the neurovisceral integration model (e.g., ventromedial prefrontal cortex) and in emotion regulation (e.g., anterior cingulate). However, higher self-congruency scores were related to heart-to-brain-driven interplay in brain regions involved in emotion regulation and empathy. Together, the present findings suggest that, while global brain-to-heart-driven interplay occurs on average, it is heart-to-brain-driven interplay that reflects higher self-congruency. Given the impact of heart-brain interplay and self-congruency on mental health, further investigations on each concept could be interesting in developing tools for early intervention.