Babies respond to sad voices at three months old

Babies as young as three months are able to tune in to the sound of voices and pick up on different emotions, even when they are asleep, a study found.

Researchers from two London Universities used functional magnetic resonance imaging (fMRI) to look at the brain activity of 21 sleeping babies, aged between three and seven months.

As they slept, the scans recorded how different parts of the babies brains responded to emotionally neutral sounds made by humans such as coughing or sneezing, as well as positive and negative sounds such as laughing or crying. Familiar non-human sounds such as those made by toys or running water were also played.

A part of the brain, the temporal cortex, known for processing human vocal sounds in adults, became more activated when the babies were played the sound of human voices.

Another part of the brain involved in processing emotion in adults, responded more to sad sounds, as opposed to happy or neutral ones.

The researchers say the findings suggest that the regions of babies brains which process sound are more sensitive than previously thought.

Dr Evelyne Mercure at University College London said: "Our results suggest that the infant temporal cortex is more mature than previously reported.

"It is rare to see that specialised areas exist in the brain so early in development."

The researchers also said the study findings fit in with past research which suggest that babies are able to extract subtle information from human speech.

Newborns prefer to listen to their mother’s voice and their mother tongue. Young infants can also differentiate between the voices of men and women, children and adults.

Dr Anna Blasi at King's College London, said: "The human voice is such an important social cue, which might explain why the brain processes it so early - this may represent the very first step in social interaction and language learning."

The findings are published in the journal Current Biology.

This article was published on Fri 1 July 2011