A recent study shows that premature babies' brains process speech before they are fully formed.
Full-term babies demonstrate incredible linguistic aptitude after they are born, having the ability to recognize their mothers' voices, differentiate between two languages they heard while in the womb and even recall short stories read to them before birth.
But neuroscientist Fabrice Wallois of the University of Picardy Jules Verne in Amiens, France and his team of researchers wanted to explore more deeply how this ability actually develops.
"The question is: what is innate, and what is due to learning immediately after birth?" Wallois asks.
In an effort to answer that question, Wallois and his team began examining babies born two to three months premature: infants in whose brains neurons have yet to reach their destinations, in which connections in the upper brain are just forming and links between the inner ear and cortex are newly formed.
The tests involved playing soft voices to the babies while they were sleeping and monitoring their brains using infrared wavelengths.
The results of the study showed that linguistic connections within the cortex were already functioning, meaning that at least part of these linguistic abilities are inborn and do not require repeated sound exposure. The infants' brains could tell the difference between male and female voices and could also differentiate between the sounds "ga" and "ba," a more sophisticated task. The areas of the cortex that were used by the infants were the same that adults use for high-level linguistic understanding.
Janet Werker, development psychologist at the University of British Columbia in Vancouver, calls the findings "remarkable" and feels they suggest that the brain could be more sensitive than ever believed. The debate between learned and developed linguistic ability, however, will most certainly continue.
"It is possible that the experience of birth triggers a set of processes that prime the brain of a premature infant to respond to language in ways that a same-aged fetus will not," Werker says.
Results from the study are published in "Proceedings of the National Academy of Sciences."
