A new study has discovered that women’s brains are hard-wired to respond to a baby’s cry, while men do not seem to react at all. Research, carried out by National Institute of Child Health in the U.S., asked 18 men and women to let their minds wander. During this time the scientists conducted brain scans. A new study has discovered that women’s brains are hard-wired to respond to a baby’s cry, while men do not seem to react at all. Research, carried out by National Institute of Child Health in the U.S., asked 18 men and women to let their minds wander. During this time the scientists conducted brain scans. 'Determining whether these responses differ between men and women, by age, and by parental status, helps us understand instincts for caring for the very young,’ study co-author Marc Bornsteinfrom the National Institute of Child Health and Human Development told Medical Daily. Although brain activity patterns differed between men and women, there was no difference in the brain patterns between parents and non-parents. The researchers also played the cries of infants who were later diagnosed with autism. Interestingly, hearing these cries interrupted the mind wandering of both men and women. A previous study has shown that the screams of infants who develop autism tend to be higher pitched than those of other babies and that the pauses between cries are shorter. It has been long known that women's bodies react to the sound of babies after pregnancy. Soon after birth, a woman's 'letdown reflex' — the reflex that releases the milk produced by breasts — needs time to adjust to the sensation of feeding. Frequent breastfeeding will help the reflex become attuned to particular stimulation, but until then, many sensations such as hearing screams and even certain thoughts may trigger lactation (the release of milk from the breast).