MOTHERS get a high similar to taking cocaine when they look at their own smiling baby, which may explain why those with drug addictions can neglect their own infants, a study has found.

A former student from the University of Queensland studied brain scans of 28 new mothers taken as they looked at photographs of their own happy babies and found that parts of the brain, such as the substantia nigra, the striatum and the frontal lobe - which are involved in processing emotion, cognition and behaviour - all lit up.

Those same areas, known as the key dopamine-associated reward-processing regions of the brain, were stimulated when people saw their lovers, beautiful faces or sexual scenes or consumed drugs such as cocaine or amphetamines, said Lane Strathearn, now an associate professor of pediatrics at the Texas Children's Hospital in Houston.