Infant and Toddler Research
All of our studies are non-invasive. Most of the infant studies use a test called "headturn preference." Infants participating in one of these studies sit on the lap of their caregiver in a sound-proof booth. During the first phase, called "familiarization" they listen to sounds (either language or music) that we want them to learn about. During the second phase, the test phase, they listen to new sounds that are either consistent or inconsistent with the pattern of the familiarization sounds. They listen to these consistent and inconsistent test trials for as long as they are interested (as long as they look toward the speaker that is playing the sounds), and we measure how long they listen to each kind of sound to determine which type they prefer. Using this technique, we attempt to answer two questions: First, what knowledge of their native language do infants have when they visit us in the laboratory? Second, what can infants learn about a new language or musical pattern in a very short time in the laboratory?
In addition to the following studies run by the Tweety Lab, the Tigger Lab has studies for infants and toddlers, ranging from 4.5 months to 5 years. Contact the Tigger Child Cognition Lab for more information.
Current Infant Studies:
Languages have different types of rules. We have recently discovered that one type of rule (often called Type II) is readily learned by 11-month-olds but not by adults. Another type (called Type IV) is learned by adults, but we don’t know if infants can learn it. Our current research with 11-month-olds compares 11-month-olds ability to learn Type II vs. Type IV rules. Our hypothesis is that as infants become better and better at recognizing words, their abilities to learn Type II rules should decrease and their abilities to learn Type IV rules should increase. Since 11-month-olds are not yet very proficient at rapidly recognizing words, they should be good at Type II and not as good at Type IV.
Children learning English produce forms like "breaked" or "catched" at around 3 years of age. These forms, called past tense overregularizations, show that children have implicitly discovered the rule "add -ed to a verb to create the past tense." But does it take children until age 3 to discover this rule? Our work seeks evidence that the past tense rule can be found in 16-month-olds.
Our study with 20-month-olds parallels our study with 11-month-olds, where we predict that as infants become better and better at recognizing words, their abilities to learn Type II rules should decrease and their abilities to learn Type IV rules should increase. Since 20-month-olds are are becoming very proficient at rapidly recognizing words, they should be good at Type IV and not as good at Type I1, which makes them more like adults than 11-month-olds.