Additionally, we observed a positive correlation between activity in the left putamen and increased selective attention to babies in OT-treated women. The putamen belongs to the mesolimbic reward system and is part of the striatum. Equivalent to many other studies the detected activation appeared only in participants that were treated with OT15. We suppose that this finding supports the idea that OT increases the reward value of babies, probably as an adaptation to motivate caretaking behavior through mesolimbic-reward pathways37. This assessment is also supported by previous reports that have demonstrated OT-dependent activations in areas of the reward system as consequence of listening to crying babies (amygdala and insula42), to laughing babies (amygdala43) and processing of child pictures (globus pallidus44). Yet, the OT-related response in the putamen did not parametrically change with the amount of BS inherent to the presented pictures. This indicates a rather general mechanism that may ensure reflexive attention to babies regardless of their cuteness.