The acquisition of wh-questions (With George Hollich)
This is a video study (using the Split Screen Preferential Looking paradigm).  In the study we show infants (13 month olds, 15 month old and 20 month olds) a video where one object (e.g., an apple) hits another object (e.g., a flower).  Then we show the two objects on a split screen and ask a question (e.g., what did the apple hit? or what hit the flower?).  As a control we also ask simple `where' questions (e.g., where is the apple?). We found that 15-month-olds looked significantly longer at the answer to the question for both the where and subject wh-questions. 20-month-olds looked longer at the answer to the question for all three types of questions. Here is a draft of the paper: Infants' and toddlers' comprehension of subject and object wh-questions.
 

The acquisition of VP as a prosodic unit (with Peter Jusczyk)
This study uses the Head Turn Preference procedure to study the acquisition of VP in 6-month-old infants.  In this study we ask whether infants prefer VPs with natural sounding prosody or unnatural sounding prosody, i.e., do infants prefer to listen to a verb and its object as one prosodic unit or a verb and its object composed from two separate prosodic units.
 

Acquisition of NPs as a prosodic unit (with D. Kemler-Nelson, M. Soderstrom, P. Jusczyk)
The same study as the VP study, but with NPs instead and prosodic boundaries which coincide with phrasal boundaries and not clausal boundaries in the ill-formed condition.

Wh-questions 3 & 4 ( with Joe Hankin (Brown U), G. Hollich and P. Jusczyk)
In order to make certain that infants were not using an elimination strategy by which they simply looked at the object not overtly mentioned in the question in wh-questions 1&2 we designed a third study. In this study we introduced a third object, e.g., a bouncing banana, to the action scene in section1 of the experiment as well as to the split screen display. We expected that if infants were simply using an elimination strategy to answer the question then in a split screen display with the target and the distractor object (the banana), infants might look equally long to both objects. Infants did not exploit this strategy. When the target object was paired with the distractor object we found that both 15- and 20-month-olds looked longer to the target object for the subject wh-questions, but that only the 20-month-olds looked longer to the target object for the object wh-questions. This finding provides further evidence that the 15-month-olds inability to answer the object questions is a grammatical deficit rather than a visual or semantic deficit. We also tested infants on the two original objects (the apple and flower). We found that both 15- and 20-month-old infants did not look longer at the target object when the distractor object was present in section1 of the experiment. This seems to indicate that there is an attentional component to question comprehension, i.e., when there are three objects moving on the screen the infants are able to figure out that two objects are involved in a hitting action and one is not, but they are not able to make a more fine grained appraisal about which object caused the hitting action.

Pitch accent and information status ( with Cindy Fisher (U of Illinois), Song (U of Illinois), Kris Onishi (U of Illinois) & P.Jusczyk)
New items to the discourse or rather unmentioned items are canonically accented whereas given items (or recently mentioned items) are deaccented. It has also been shown that adults prefer to listen to sentences in which items follow this pattern, that is, a pattern where given or repeated items are deaccented and new items have pitch accents. Specifically Nooteboom and Terken (1982) and Terken and Nooteboom (1987) showed that reaction times to given items with pitch accents were significantly slower than to given items without pitch accents, and the reverse was true for new items. These findings suggested to them that accent did play a role in processing and it was not just that listeners listened harder to accented words, but rather that they may process accented words and deaccented words differently. This PLP study seeks to find out if children also show this preference, i.e., do children assume that deaccented items are discourse old entities and accented items are discourse new and do they process new items better when they are accented.

Word learning and pitch accents
This is a video study (also using the Split Screen Preferential Looking paradigm).  In this study we ask whether young children (20 month olds) learn novel words better when they hear them with a H* pitch accent.  We teach children two new words for some funny computer generated pictures.  Some of the words are accented and some are deaccented.  Then we test to see whether children learned the deaccented or the accented words better.
 

Syntactic boundaries, coarticulation and the word boundary problem (with Elizabeth Johnson)
There is less coarticulation between words when they span a higher syntactic boundary.  In this study we look at whether children will segment words out of continuous speech more easily when the words occur at a high syntactic boundary vs. a lower one.