Affective or cognitive interpersonal emotion regulation in couples: an fNIRS hyperscanning study

Sadness regulation is crucial for maintaining the romantic relationships of couples. Interpersonal emotion regulation, including affective engagement (AE) and cognitive engagement (CE), activates social brain networks. However, it is unclear how AE and CE regulate sadness in couples through affective bonds. We recruited 30 heterosexual couple dyads and 30 heterosexual stranger dyads and collected functional near-infrared spectroscopy hyperscanning data while each dyad watched sad or neutral videos and while the regulator regulated the target's sadness. Then, we characterized interbrain synchronization (IBS) and Granger causality (GC). The results indicated that AE and CE were more effective for couples than for strangers and that sadness evaluation of female targets was lower than that of male targets. CE-induced IBS at CH13 (BA10, right middle frontal gyrus) was lower for female targets than for male targets, while no gender difference in AE was detected. GC change at CH13 during CE was lower in the sad condition for male targets than for female targets, while no gender difference in AE was discovered. These observations suggest that AE and CE activate affective bonds but that CE was more effective for regulating sadness in female targets, revealing different neural patterns of cognitive and affective sadness regulation in couples.