Fetuses might be able to differentiate between languages, a new study from the University of Kansas suggests. Researchers say the differences were clear from changes detected in the fetuses' heart rhythms.
In the study, a single bilingual speaker made two recordings — one in English and one in Japanese — that were then played to the fetuses of two dozen pregnant women. English and Japanese are thought to be rhythmically distinct, providing a helpful case study in language contrast. The fetuses were on average about one month away from full term.