Babies can remember lullabies played to them while still in the womb up to several months after birth, a new study of 24 women and their infants found.

Half of the women played the song "Twinkle, Twinkle Little Star" five days a week during their final trimester, while the others did not. After the babies were born, the researchers monitored their brains while the song was played. The brains of those who had heard the melody in utero reacted more strongly to it up to four months after birth in comparison to the control group, the researchers found.

According to Eino Partanen, who is currently working to finish his dissertation at the Cognitive Brain Research Unit, the results lay fundamental groundwork in understanding early learning.

"Even though our earlier research indicated that fetuses could learn minor details of speech, we did not know how long they could retain the information," he said. "These results show that babies are capable of learning at a very young age, and that the effects of the learning remain apparent in the brain for a long time."

The pioneering report is further useful in establishing a clearer understanding of fetal memory development, notes Dr. Minna Huotilainen, principal investigator.

"This is the first study to track how long fetal memories remain in the brain," Huotilainen said, "The results are significant, as studying the responses in the brain let us focus on the foundations of fetal memory. The early mechanisms of memory are currently unknown."

Current theories state that some of the same mechanisms in the babies' brains are used to process singing and speech. For this reason, researchers speculate that exposure to music may support a baby's speech development.

The study was published in the journal PLOS ONE.