In one study, for example, 12 pregnant women played a CD loudly five times each week during the last trimester of their pregnancy. It contained excerpts from several different melodies, and there was talking in between the excerpts. However, the important melody on the CD was “Twinkle, Twinkle, Little Star,” which was repeated 3 times. The babies developing in these mothers’ wombs heard this melody 138 to 192 times before they were born. The mothers then destroyed the CD once their child was born, so that there was no chance the baby could hear the contents of the CD afterwards.
Shortly after birth and again at the ripe old age of 4 months, the babies were played a modified version the “Twinkle Twinkle Little Star” melody nine times. In this modified version, 12.5% of the notes from the original melody were randomly changed to a single note – “B.” While the modified melody was playing, an EEG recorded the electrical activity in each baby’s brain. The researchers also chose 12 babies whose mothers had not been given the CD and did the same thing to them. The babies who had heard the CD in the womb had significantly higher electrical brain activity when the modified notes were played, indicating that these notes were unfamiliar to them. For the babies whose mothers had not been given the CD, the electrical activity in the brain was the same during both the original notes and the changed notes.1 This gives strong evidence that babies can learn the music they hear while they are in the womb.
Of course, one could argue that animals respond to music, so perhaps this is not a uniquely human trait. However, our means of communication is unique to humans, and even in the womb, babies are already starting to learn how to talk. For example, Christine Moon and her colleagues studied 80 babies who were 7-75 hours old. Half of the babies were from the U.S., and the other half were from Sweden. They gave each baby a pacifier that controlled an audio presentation. When the baby sucked on the pacifier, vowel sounds would be played. Some of the vowel sounds were from their native tongue, and some were from a foreign language. They found that the babies sucked on the pacifier more when a foreign vowel sound was played. This indicated that the babies were much more familiar with the native vowel sounds, and they recognized the foreign vowel sounds as being different.
Interestingly enough, the babies who were tested just 7 hours after birth performed essentially the same as the babies that were tested 75 hours after birth. This indicates that the babies’ responses had nothing to do with what they had heard since birth. Thus, the authors conclude that the babies were more familiar with the vowel sounds they had heard while they were in the womb. The authors state:2
Our results indicate that neonates’ perception of speech sounds already reflects some degree of learning.
Of course, the level of learning is yet to be determined. However, the fact that a baby in the womb is learning language (even at a very rudimentary level) indicates that it is fully human.
Not only do babies recognize vowel sounds that they hear while in the womb, they also recognize words they hear – even when a word has been made up! The same researcher who did first study I discussed also headed up a study in which 17 pregnant Finnish women were instructed to play a recording of a made-up word (tatata) loudly 5-7 times a week during their third trimester of pregnancy. The recording said the word over and over again in two bursts of four minutes each. Most of the time, the word was pronounced exactly the same, but every once in a while, it would be pronounced slightly differently.
An average of five days after each baby was born, he or she heard the same recording, and an EEG measured the electrical activity in the baby’s brain. The electrical activity shot up when the baby heard the odd pronunciation of the word, indicating that the baby knew this was different from the standard pronunciation. The researchers did the same thing with 16 babies whose mothers had not played the recordings at all, and the babies registered no spike in electrical activity when the word was pronounced oddly. This indicates that the babies who heard the made-up word in the womb remembered it.3
So not only do babies learn melodies in the womb, they learn the basics of speech and learn to recognize certain words. When you combine this with the genetic evidence, the social interaction evidence, and the brain-development evidence, it is clear that even in the womb, babies are fully human.
2. Christine Moon, Hugo Lagercrantz, and Patricia K Kuhl, “Language experienced in utero affects vowel perception after birth: a two-country study,” Acta Paediatricia, 102(2):156-160, 2013 (Available online)
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3. Eino Partanen, Teija Kujala, Risto Näätänen, Auli Liitola, Anke Sambeth, and Minna Huotilainen, “Learning-induced neural plasticity of speech processing before birth,” Proceedings of the National Academy of Sciences of the United States of America, doi:10.1073/pnas.1302159110, 2013
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