The researchers concluded that mothers are inherently 'hard-wired' to hear and respond to an infant's cry.

Each mom, when hearing her baby cry, had virtually the same brain activity which spurred her to move, speak and respond to the child. The brain regions seen were the supplementary motor area which processes the intent to move or speak, the superior temporal regions that process sound and the inferior frontal area which is related to the production of speech. When looking at the scans of the mothers as they heard their child cry, they found common brain areas were consistently active, in both first-time mothers and experienced moms. Did they respond by talking to the baby, picking up the child, feeding or holding or distraction? What the researchers were looking to record what each mother did when their baby would cry. The babies were all five months of age at the time of the study. Researchers observed the moms and babies for an hour at their homes, to record how each mother and baby interacted. To get a broad cross-section of information the project involved study volunteers in 11 countries (France, Argentina, Brazil, Italy, Kenya, Cameroon, the United States, Belgium, Israel, South Korea and Japan.) In total there were 684 mothers in the study sample. These types of scans can pinpoint which areas of the brain are active in response to specific stimuli. Anything that the study volunteer sees or hears during an fMRI scan will show up in the MRI in real time. The scans conducted were functional MRIs (fMRI) that show brain activity while the participant is performing a task, reading words or viewing something. Using brain imaging and behavioral observations, the team investigated the underlying brain activity when a mother hears a baby cry. In the United States, many parents feel that children eventually need to 'cry it out' when waking at night and in other countries, an infant will sleep in the same bed with mom and dad, often until they reach school age. Child-rearing practices vary significantly from country to country. Researchers at the Eunice Kennedy Shriver National Institute of Child Health and Human Development wanted to know if a mother's response to an infant's cry is the same in different cultures. Other responses can be anxiety, or a need to rush to the baby and soothe whatever is making the infant cry. If she is breastfeeding and hears a baby cry, her milk will immediately start to flow. A mother's body responds to this cry in many ways. As any mother can attest, hearing her child cry, especially in infancy, evokes a powerful response.

When does a fetus have brain activity