Tweety Language Development Lab

Infants Update Their Guess About the Rules of Language as They Get More Information

11-month-olds are influenced by the order in which they hear words that reflect rules about how sounds are combined in their language. If the words occur in an order where many adjacent words can mislead infants about the rule (e.g., 2 words starting with p accidentally occur next to each other), infants don’t learn the rule.  This finding tells us that infants are updating their best guess about the rules of their language as each new piece of information comes in.

Click here to download the original Developmental Science article. 

It Only Takes 4 Words of Input for Infants to Learn a New Language Rule

11-month-olds are able to learn a new rule about how sounds are combined in their language from just four words of input.  A question that arises from this research is, if infants learn so quickly, why aren’t they done learning language by the time they are age two years? Current research in the Tweety and Tigger Labs aims to tease apart what infants learn from a brief learning session and what they remember and use as they are becoming more mature language users.

Click here to download the original Cognition article.

Infants Pay More Attention to Language Patterns When They Think They Can Learn Those Patterns

17-month-olds were allowed to listen for as long as they wanted to lists of masculine and feminine words from a foreign language.  For some of the infants, the fact that there were two types of words (masculine and feminine) with different endings was more apparent, and for other infants the pattern was more obscure.  Infants who had the more transparent pattern listened longer, suggesting that infants devote more attention to language patterns when they sense that they are able to learn these patterns.

Click here to download the original Developmental Science article. 

Younger Babies Can Detect Patterns in Music that Older Babies Cannot

Research from another laboratory recently showed that 7-month-olds were unable to learn an AAB or ABB pattern (with repetition at the beginning or end) when the pattern was produced with musical notes, but they could learn the pattern when it was produced with syllables. Does this finding mean that there is something special about language?  Or could it be that experience with music makes repetition less noticeable.  For example, most music is "smooth", so that if you're hearing one note, the next note is likely to be either the same or just one step up or down.  If babies have learned about the smoothness of music, they may come to believe that there is nothing special about repetition, because it is just part of the musical system.  This view suggests that babies who have not yet heard enough music to infer the smooth structure may find repetition more interesting and therefore learnable.  To test this suggestion, we tested 4-month-olds on the AAB and ABB musical patterns that had eluded 7-month-olds in the earlier study.  Counter to the claim that there is something special about language, they learned these patterns easily!

Click here to download the original Cognition article.

Language Patterns and Rule Learning in 9-month-old Babies

A number of researchers, including the famous Noam Chomsky, have suggested that babies might be biased to learn patterns that occur in real languages. Languages of the world have many rules about which syllables in words should be stressed. Many languages have a rule that syllables ending in a consonant should be stressed. No languages have a rule that says that syllables starting with 't' should be stressed. Consistent with that suggestion, research from our lab has shown that 9-month-olds are able to quickly learn the 'ends in consonant' rule, but not the other rule.  However, we have also found that younger babies (7-month-olds) are able to learn the rule that does not occur in human languages.  Therefore, it appears that the forms languages take are shaped by what is easy for language users to perceive and produce, and do not come "prewired" in babies.

Click here to download the original Language Learning and Development article.

Babies Know That They're Learning, Even Before They've Learned

One mystery about how babies learn is how they choose the learning problems to tackle in the first place.  In any given situation, a baby could focus on any number of aspects of the environment to explore.  How do they avoid wasting their time by focusing on aspects where there is nothing to learn, or learning problems that they are not yet ready to solve? Recent research from our lab suggests that infants are able to detect whether or not they are learning and pay more attention to aspects of their environment that are learnable.  We let 17-month-olds listen to a language that other babies had learned or to one that other babies (and adults) found impossible to learn.  When babies showed that they were no longer interested, the experiment ended. The babies who heard the learnable language listened much longer than the other group and began showing increased interest after they had heard only about 45 seconds of the language.  Infants in the earlier study who were tested on their learning, not on their interest level, took about 3 minutes to learn the language. Therefore, it seems that babies know they're making progress on a learning problem in much less time than it takes them to actually solve the problem.

Babies Detect Multiple Patterns in the Same Input

Nine-month-old infants listened for 2 min. to  3-syllable 'words' with an AAB pattern, in which the first syllable repeats (e.g., laylaydee, weeweejay, etc.). The words either had another pattern embedded or not.  The embedded pattern was that all of the words ended in the syllable 'dee'.  Infants who heard the words without the embedded pattern were able to recognize as familiar new AAB words when we tested their interest.  But infants who heard words with the embedded pattern were only able to recognize new words with the embedded pattern, not the more general AAB pattern (Gerken, 2006).  In a later study, just 3 examples of words that had just the more general AAB pattern mixed in with the embedded pattern were enough to cause infants to recognize new words with the more general AAB pattern.  This result suggests that they were considering both patterns all along and just needed a little evidence to tip them from favoring the embedded pattern to the more general pattern.

Click here to download the original Cognition article.

We know that the words "research" and "experiment" tend to bring about more questions than they do answers. Here are some of our most frequently asked questions to help you out. If your question isn't answered here, please consider submitting it to us.

• Where are you located?
  A: In the Psychology Building on the University of Arizona campus. Our physical address is: 1503 East University Boulevard.

  What do your studies involve?

• A: A study usually involves having your baby sit in your lap in a sound-proof booth while we play some artificial language samples to your child. While this happens, we measure what your child appears to be most interested in to help us figure out what babies are capable of learning about a new, artificial language in a short visit to the lab. For more detailed information, please visit the "A Typical Lab Visit" tab above.
   

• How do I sign up to be contacted for study opportunities?
  A: You can call us or email us with your contact information, and our lab manager will return your email or phonecall to fill you in on the next upcoming study which your child is eligible for. 
   

• Can I change my mind about participating after I've signed up?
  A: Of course. Your permission for your child to participate in our studies can be withdrawn at any time, for any reason, and without affecting your or your child's affiliation, standing, or relationship with the University of Arizona and any departments or programs therein.
   

• When do you schedule appointments?
  A: We schedule appointments 9am-5pm Monday-Friday. However, we do understand that many families have two working parents and cannot make an appointment during our typical business hours. If that's the case, let us know when you contact us and we'll do our best to work out an evening appointment or a Saturday appointment for you.
   

• What forms will I have to fill out or sign?
  A: You'll have to fill out a short questionnaire as well as a parent permission form for the particular study that your child is participating in. All of these forms can be accessed above by clicking on the tab "A Typical Lab Visit"
   

• I have other children and I don't have a babysitter. Can I bring them to my appointment?
  A: Yes! Our lab is staffed with hardworking people who love to take a break from the day to read books or play games with your kids. The only thing we ask is that you let us know while you are scheduling your appointment, so we can plan accordingly.
   

• What information do you need for me to sign up?
  A: We need the following information in order for your child to participate: Your name, your child's name, a good phone number and/or email address to contact you at, your child's date of birth, your child's birth weight, your chid's gender, and your child's birth term (weeks gestation, assuming 40 weeks = full term). 
   

• Will you sell my information to anyone?
  A: No, we are not permitted to sell your information to anyone. Your information is kept in a password-protected file at all times.
   

• Is there compensation for participating?
  A: Yes. For every visit to the lab, your child gets to take home a board book.

• Does participation cost me anything?
  A: There is no cost to participate.
   

• The UA seems busy and parking seems complicated. Do you offer parking for free?
  A: We do offer free parking during the time of your appointment just outside of our building.
   

• Do you conduct any invasive studies or collect any biological samples?
  A: No, we do not. 
   

• How long do your studies take?
  A: Most of our studies take less than 10 minutes of actual participation, with you appointment likely concluding within a 30-minute period. Our toddler study, however, does require a bit more time--approximately 45 minutes. We schedule hour-long appointments for all of our studies to allow you plenty of time to ask questions and change or feed your child beforehand, if need be. Most appointments finish far before the scheduled hour is up.
   

• Will I be separated from my child?
  A: You will never be separated from your baby or child while they are participating in one of our studies. The only exception to this is if you bring more than one child to an appointment to participate. If that's the case, we'll have you participate with each child one at a time. While you and your baby are participating, your other child(ren) will hang out with one of our awesome Research Assistants and color, read, or play games. They will also be given the opportunity to watch you and your other child from a monitor while you participate, if they are sensitive to being separated from you.
   

• Why do you use artificial languages in your studies?
  A: Natural languages are very complicated. This complexity would make it difficult for us to narrow down what babies might be most interested in while participating in a study. By utilizing artificial language samples, we are better able to incorporate specific information that we think might be useful to babies when they are learning a new language and test them to see if it, indeed, appears to help. Oftentimes, we find that some cues that help babies of a certain age to learn a new language are of no help to babies at a different age!

, 2013.