An eye tracking system for monitoring face scanning patterns reveals the enhancing effect of oxytocin on eye contact in common marmosets.

•A newly established method for eye tracking in common marmosets was developed.•Face scanning patterns in common marmosets were characterized.•Oxytocin significantly enhanced the change in eyes/face ratio compared to the vehicle condition.•L-368,899, an oxytocin receptor antagonist, completely blocked oxytocin - induced increase in the change in eyes/face ratio.