Tweety Language Development Lab

Department of Psychology

Infant and Toddler Research

All of our studies are non-invasive. Most of the infant studies use a paradigm called "headturn preference." Infants participating in one of these studies sit on the lap of their caregiver in a sound-proof booth. They listen to different kinds of passages (either language or music), and they are allowed to listen for as long as they look toward the speaker playing the passage. We measure how long they listen to each kind of passage 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 in a very short time in the laboratory?

We also run a study for 2-6 year-olds. Please read the description below for more information.

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:

4 months
In spoken language, the ends of phrases and clauses tend to have particular pitch contours, and the last syllable is usually lengthened. In the 4- and 16-month-old studies, we are asking whether these same acoustic cues also help infants locate and remember musical phrases.

7.5 months
We know that at 14 months, infants learn words better when both words are spoken by multiple talkers. With 7.5-month-olds, we are asking whether this is also true for younger infants' basic discrimination of similar sounds like "bazz" and "pazz." Do babies have an easier time telling these sounds apart when there are multiple talkers producing each sound? Or does this variation in talkers make it more difficult for babies to pick up on the change from "bazz" to "pazz"?

9 months
For 9-month-olds, we have two brief studies: We have recently found that 17-month-olds, after listening for only 20 seconds, show more sustained interest  in a new language that has a consistent structure than one that does not. The first current 9-month study asks whether 9-month-olds show the same ability. The study involves infants' listening for as long as they want to 60 words in which the placement of stress on syllables follows consistent rules, or to the same words plus 9 words that violate the rules. Will the presence of the rule-violating words decrease their interest in the second condition?

Our second 9-month infant study is a vision study presented by Jeannette Bell, one of our Research Assistants. Mrs. Bell is exploring how infants learn 3-shape sequences with a color pattern that follows an order of "AAB" or "ABA." This project is for her Honor's Thesis.

11 months

11 mos study description coming soon!

14 months
With 14-month-olds, we are teaching infants similar words like "bazz" and "pazz" that are spoken by multiple talkers. We are interested in finding out when this variation in the voices saying the words helps infants learn these new words, and when it does not help. When both words are being spoken by the same set of talkers, we know this helps infants learn similar words. But what happens when the words are spoken by different talkers? For example, what if one word is spoken only by female talkers, and the other is spoken only by male talkers? Will this structure (male vs. female) also help infants learn the words, or will it distract them from the words themselves?
16 months
In spoken language, the ends of phrases and clauses tend to have particular pitch contours, and the last syllable is usually lengthened. In the 4- and 16-month-old studies, we are asking whether these same acoustic cues also help infants locate and remember musical phrases.

17 months

17 mos study currently on hold--Please check back soon!

19 & 20 months
When reading the words on this page, it is easy to locate the ends of clauses and sentences, because they tend to be marked with commas or periods. In spoken language, however, this information is not available. The current 19-month-old studies focus on how infants use the prosodic (i.e., rhythmic and intonational) structure of sentences to find the boundaries of phrases, clauses, and sentences. We are also investigating the role of previous experience, by asking whether infants can use unfamiliar prosody to locate clauses in a foreign language.
 

Current Toddler Studies:
Effects of Phonological Variability: 2 to 6 years

3.5 year-old Abby

The same word, when pronounced by different people, will not sound exactly the same. And yet, we consistently recognize a word as a single word, despite these differences in pronunciation. It has been found that infants actually learn words better when they hear them pronounced by multiple speakers - that is, they are learning the words better when the words contain phonetic variation. The current study asks whether this improvement in word learning under conditions of phonetic variation is related to age and phonological maturity. This study takes approximately 45 minutes to an hour and utilizes a computer game with animals that the child will be asked to name or identify.