Language Development affected by Mother's Depression

As we have been learning in class, there is a critical period for language development in babies. In Elizabeth Landau's CNN Article,  "Does mom's depression affect baby's language?", she states that babies are born with "linguistic super-powers".  Janet Werker, from University of British Columbia in Vancouver, conducted a study to investigate what may influence when babies are no longer sensitive to non-native languages. We already know that babies are sensitive to different phonemes used in different languages., but this study was designed to "explore language development milestones". 

The study contained three groups of babies, one whose mothers "took antidepressants during pregnancy", another group whose mothers were depressed but did not take any medication, and a group whose mothers did not suffer from depression. The babies then completed tasks where they had to discriminate between auditory sounds from two languages and the visual speech without the auditory component.

Werker's findings supported the fact that babies were able to discriminated between the languages at 6 months but were unable to do so at 10 months. Interestingly, the experimental groups showed deviation from this norm. Babies whose mothers did not take medication for their depression seemed to exhibit a delay in their critical period, as they were unable to discriminate between the languages at 6 months but were successful at 10 months. Furthermore, those whose mothers took antidepressants during the pregnancy showed the opposite effect in that they were not successful in the discrimination tasks at 6 months or 10 months of age, possibly because their critical period had passed prematurely. 

While researchers are not sure as to the reasons for such variability, one hypothesis is that the chemicals from the mother's depression or the antidepressants themselves could have effected the baby's brain development. Another possibility is that babies with depressed mothers were not exposed to the same levels of "motherese".

While I did find the sample size to be a little small, and am not sure how representative the data actually is, I am curious as to whether other stresses during pregnancy or even how other medications may affect babies' critical period. It would also be interesting to see if this disparity is seen across cultures, or whether cultural remedies or attitudes to depression may also play a role in the critical period. Perhaps brain development in Wernicke's area, which is involved in the comprehension of language, or even Broca's area, which is involved in the production of language, is affected by the presence of antidepressents or lack of interaction with the mother. It could also be possible that varied level of vascularization could contribute to such effects. 

Source: http://thechart.blogs.cnn.com/2012/10/08/does-moms-depression-affect-babys-language/