Developmental changes in social attention and oxytocin levels in infants and children

Oxytocin (OT) signalling represents one of the most critical systems involved in human social behaviour. Although several studies have examined the relationship between social functioning and peripheral OT levels, the association between OT and the development of social attention has not been well studied. Therefore, we investigated the developmental relationship between gaze fixation for social cues and OT levels during young childhood. We examined visual attention using an eye tracking system in infants and children (5–90 months of age) and measured the concentration of OT in saliva samples. We observed a negative association between age and both attention toward social cues and salivary OT levels, and a positive association between age and attention for non-social cues. We also observed that salivary OT levels were modulated by polymorphisms in oxytocin receptor (OXTR) rs53576. Our results suggest that there is an age-dependent association between visual attention for social cues and OT levels in infants and children, and that the development of visual attention to the eyes as social cues is associated with both OXTR polymorphisms and OT levels. Such findings indicate that OT and OXTR status may provide insight into the atypical development of social attention in infants and young children.