Neural responses to instructed positive couple interaction: An fMRI study on compliment sharing

Love is probably the most fascinating feeling that a person ever experiences. However, little is known about what is happening in the brains of a romantic couple –the central and most salient relationship during adult age – while they are particularly tender and exchanging loving words with one another. To gain insight into nearly natural couple interaction, we collected data from N = 84 individuals (after including N = 43 heterosexual romantic couples) simultaneously in two functional magnetic resonance imaging scanners, while they sent and received compliments, i.e. short messages about what they liked about each other and their relationship. Activation patterns during compliment sharing in the individuals revealed a broad pattern of activated brain areas known to be involved in empathy and reward processing. Notably, the ventral striatum, including parts of the putamen, was activated particularly when selecting messages for the partner. This indicates that the anticipation of a beloved person’s positive reaction is rewarding already. Therefore, we provide initial evidence that the neural systems underlying giving a verbal treat to a romantic partner seem to involve dopaminergic basal ganglia. These results can have important implications for the neurobiological mechanisms protecting and stabilizing romantic relationships, which build a highly relevant aspect of human life and health. Significance Statement Not only is being in a romantic relationship and interacting with a partner linked to subjective joy, it is also to mental and physical health. To investigate central brain mechanisms of couple interaction, we used a realistic positive interaction task in 43 heterosexual couples in two parallel fMRI scanners that tests the neural responses to compliment sharing. Receiving compliments resulted in a broad range of reward-related brain networks and empathy-related networks. Selecting compliments to send to the partner involved the dopamine-rich ventral striatum even stronger, indicating the anticipation of giving a treat to one’s partner is rewarding already. These findings suggest that neural reward mechanisms underlying joy during couple interaction are involved in maintaining relationships and promoting health.