While babies are born ready to learn any of the world's languages, the crucial developmental period when they attune to their native languages can change due to environmental influences such as maternal depression or a bilingual upbringing, according to new University of British Columbia research.
The findings, presented today at the American Association for the Advancement of Science (AAAS) Annual Meeting in Vancouver, B.C., is among the first to explore the impacts of maternal mental health and antidepressant exposure on the mechanics of early language acquisition. The preliminary findings provide important new insights into early childhood development and mother's mental health and will inform new approaches to infant language acquisition, the researchers say.
Previous research by UBC Psychology Prof. Janet Werker has found that during the first months of life, babies rapidly attune to the language sounds they hear and the sights they see (movements in the face that accompany talking) of their native languages. After this foundational period of language recognition, babies begin focusing on acquiring their native tongues and effectively ignore other languages.
However, in findings from two studies, Werker reports that this key developmental period - which typically ends between the ages of eight and nine months - can change. In one study, Werker finds the period lasts longer for babies in bilingual households than in monolingual babies, particularly for the face recognition aspects of speech.
In another study, Werker and collaborators at the Child & Family Research Institute (CFRI) at BC Children's Hospital and Harvard University find that maternal depression and its treatment with common antidepressant medication - serotonin reuptake inhibitors, or SRIs - can also affect the timing of speech perception development in babies. The team's preliminary findings suggest that SRI treatment may accelerate babies' ability to attune to the sounds and sights of the native language, while maternal depression untreated by SRIs may prolong the period of tuning.