The bond between a mother and her child has been cited as having many positive health effects, especially for the child’s development, but there are many unknown elements about the science behind bonding.

A recent study suggests one specific brain chemical plays an important role in the development of a healthy mother-child bond.

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Dopamine is arugably the most talked-about brain chemical. It's frequently referred to as the “feel good” neurotransmitter, which affects everything from feelings of pleasure, motivation, desire, and many others. Previous research in rodents suggests dopamine plays a role in maternal bonding, but researchers wanted to better understand the bond in humans, which had not been done before, the study authors note.

The study consisted of nineteen mothers and their children, ages 4-24 months. During home visits, the study staff collected video recordings of the mothers and their children. Afterwards, the mothers participated in a positron emission tomography, or PET, scan, which measures blood flow in the brain, followed by a functional magnetic resonance imaging, or fMRI, which also measures blood flow, but in addition provides an indirect message of brain activity.

During the scans, mothers watched a variety of videos showing their own infant and an unfamiliar infant, in a random order. The scans revealed higher levels of dopamine when mothers were watching their own babies.

“Mothers who were less responsive to their infants also secreted less dopamine when watching films of their infants. This provides us with hints as to what goes wrong in a mother’s brain when she is struggling to provide for her infant,” lead study author Shir Atzil told Medical XPress.

While this research provides an important advancement in the understanding of human social bonding, it is important to note that this is a small study and may not apply to all mothers, Paul Zak, founding director of the Center for Nueroeconomics Studies at Claremont Graduate University, said.

The study was conducted by Lisa Feldman Barrett and her colleagues at the Massachusetts General Hospital. It was published in the journal Proceedings of the National Academy of Sciences.

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