The brain scans of new moms showed heightened activity in the dopamine pathway of the caudate nucleus — a region near the center of the brain that plays a role in reward learning, the researchers said. (Dopamine is brain chemical that is linked to pleasure as well as motivation and reward.)
The researchers aren't sure if new moms undergo a hormonal change that leads to this surge of dopamine or if their reaction is influenced by the experience of smelling their own baby, the researchers say.
"It is possible that childbirth causes hormonal changes that alter the reward circuit in the caudate nucleus, but it is also possible that experience plays a role," Frasnelli said in a statement. And it's not clear if the reaction is specific to women since men were not included in the study.
The findings were detailed online this month in the journal Frontiers in Psychology.
Past research has suggested that responses to cuteness in general -- wanting to "eat up" a baby or squeeze a kitten -- are actually forms of aggression. The researchers of that study suggested the aggression was due to an overload of positive emotions that led to a sense of lost control.
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