Can You Feel My Pain? Neural-Behavioural Changes in Caregiver-Infant Dyads During Ostracism.

Behavioural and neural coordination during infant-caregiver social interaction is crucial for early emotional development and effective emotional regulation abilities later in life. This is particularly relevant to help infants deal with challenging social situations, such as being excluded from a group of others (ostracism). The coupling of neural and behavioural responses to ostracism in infants and caregivers has never been investigated in infants and caregivers simultaneously, nor how early infants perceive ostracism and how caregivers couple their behavioural and neural signals with them. In the current preregistered hyperscanning study, we investigated the effect of ostracism on neural and behavioural responses, inter-brain synchrony (N = 34) and behavioural synchrony in caregiver-infant dyads (N = 41) using a ball-game. We compared how theta power, inter-brain synchronization, and affective responses changed during ostracism. 5-7-month-old infants and their caregivers both showed increased affective responses. However, only infants, but not their caregivers showed higher theta power during ostracism. Inter-brain neural synchrony was not generally higher in the exclusion condition compared to the control conditions and highly dependent to specific contexts. These findings indicate a co-regulation process, suggesting that "more synchrony" is not necessarily better for interaction quality. Instead, effective caregiver-infant interaction may rely on the flexible modulation of synchrony, shifting between more and less synchronization depending on contextual demands. Overall, our study is the first to show that infants are sensitive to cues of ostracism experience from 5 months of age on and provides the first evidence of caregiver-infant behavioural and neural synchrony in response to ostracism. A video abstract of this article can be viewed at https://youtu.be/pXj3yu7MNw0.