The almost-universal cry of mothers upon cuddling a newborn baby - that the baby smells good enough to eat - is more than just delight and affection. It’s a very real neurological response that can be traced using brain imaging scans. Medical science has now traced that feeling’s origin, suggests why we feel it, and can even offer a pretty good explanation of why newborns smell good enough to eat.
Johannes Frasnelli, a research scientist with the University of Montreal Department of Psychology, describes this endearing baby aroma as a “means of chemical communication between mother and child.” It encourages mom’s bonding with her newborn as a means of survival, encouraging her protective instinct by activating the part of her brain that stimulates the feeling of reward or desire.
To test just the olfactory signals, Frasnelli’s team of researchers recruited two groups of 15 women each to breathe deep of the smell of two-day old babies. One group had had their own babies within three to six weeks of the olfactory test. The other group had never had children.
All study participants were non-smokers who were hooked to brain imaging systems as they sniffed the aroma only of newborn babies. None of the mothers or the babies from whom aroma samples were collected were related. By isolating the sense of smell alone, the study eliminated any intermingling stimulation that might come from sight or sound of a baby.
Brain imagery indicated all women perceived the baby aroma with the same degree of intensity but a specific part of the brains of the mothers exhibited a much greater degree of activity than this same area in the brains of the non-mothers. This area, the caudate nucleus, is in the center of the brain, straddling both hemispheres. Activation of the neurotransmitter dopamine in this area as a response to the baby aroma indicates the mothers were perceiving the baby aroma as a reward. According to Frasnelli, “dopamine is the primary neurotransmitter in the neural reward circuit.”
The experience of any satisfying desire - craved foods, alcohol, drugs, sex - stimulates dopamine production in the caudate nucleus. Stimulation here by electrodes alone has proven so overpowering that lab rats even stop eating when forced to choose between food or mechanical stimulation of the caudate nucleus. Some odors besides the smell of a baby trigger this dopamine response in the brain’s reward system but most of them do not.
Frasnelli says his research suggests the outpouring of dopamine acts as a motivating emotional response that triggers the mother’s desire to protect and may help induce her ability to breast-feed the child. That good-enough-to-eat aroma may be essential to the baby’s survival.
The University of Montreal research team focused on women only, leaving unanswered the question of whether fathers experience the same neurological response to their newborn babies, too.
Source: "Why Do You Want to Eat The Baby?" RedOrbit. 23 Sept 2013. Web. 4 Oct 2013.