Uncover how the brains of infants distinguish differences in sounds and it may become possible to correct language problems even before children start to speak, sparing them the difficulties that come from struggling with language.
New studies conducted by Professor of Neuroscience April Benasich and her Infancy Studies Laboratory at Rutgers University in Newark are revealing new and exciting clues about how infant brains begin to acquire language and paving the way for correcting language difficulties at a time when the brain is most able to change.
Benasich and her lab were the first to determine that how efficiently a baby processes differences between rapidly occurring sounds is the best predictor of future language problems. Using methods developed by Benasich and her lab, it can be determined as early as three to six months whether a baby will struggle with language development.
Benasich's research is now focused on uncovering in specific detail how the developing brain processes and distinguishes acoustic differences that arrive in rapid succession. The ability to differentiate those sounds, such as the difference between “ba” and “da,” is critically important because decoding language requires us to process tiny auditory differences occurring as quickly as 40 milliseconds. During the first months of life, the baby's developing brain also is involved in constructing an acoustic map of the sounds of his or her native language. That map allows the baby to efficiently acquire language. Apparently, however, in some infants the process seems to go awry.
About 5 to 10 percent of all children beginning school are estimated to have language-learning impairments (LLI) leading to reading, speaking and comprehension problems, according to Benasich. In families with a history of LLI, 40 to 50 percent of children are likely to have a similar problem. Many of these children go on to develop dyslexia.
Using several novel methods, including dense array EEG/ERP recordings, Benasich and her lab are able to analyze EEG, ERPs and the proportion of gamma power in infant brains. The dense sensor array allows the researchers to gently measure a full range of brain activity. Those measurements are obtained by placing a soft bonnet of sensors, resembling a hairnet with lots of little sponges, on a baby's head and then having the infant listen to different series of rapid tone sequences.
“We are finding that children who have difficulty processing rapid auditory input are not just showing a simple maturational lag, but are actually processing incoming acoustic information differently,” says Benasich.