The Chicago Tribune – Andrea Guthmann 
There’s mounting evidence to back up Fuentes’ claims. “Starting at around eight to 10 months old, there’s a change in the baby’s brain called perceptual narrowing, also referred to as neural commitment,” says Luisiana Melendez, associate clinical professor and director of the Early Childhood Bilingual/English as a Second Language Certificate Program at Chicago’s Erikson Institute, a graduate school specializing in child development. “The baby is narrowing down the range of sounds to those heard around them. If the child is exposed to only one language, usually by age 3 it becomes a little harder to discriminate the sounds of another language.” What that means is if you want your child to learn a second language, it’s best to introduce it in the first year of life. (more)