Field of Science

Boston University Conference on Language Development: Day 1

This year marks my 7th straight BUCLD. BUCLD is the major yearly language acquisition conference. (IASCL is the other sizable language acquisition conference, but meets only every three years; it is also somewhat more international than BUCLD and the Empiricist contingent is a bit larger, whereas BUCLD is *relatively* Nativist).

NOTE I'm typing this up during a break at the conference, so I've spent less time making these notes accessible to the general public than usual. Some parts may be opaque to you if you don't know the general subject matter. Feel free to ask questions in the comments.

Day 1 (Friday, Nov. 2)

What does eyetracking tell us about kid's sentence processing

The conference got off to a great start with Jesse Snedeker's 9am talk, "Negation in children's online language comprehension" (for those who don't know, there are 3 talks at any given time; no doubt the other two 9am talks were good, but I wasn't at them). I was actually more interested in the introduction than the conclusion. Over the last 15 years, the Visual World Paradigm has come to dominate how we study children's language processing. Here is how I usually describe the paradigm to participants in my studies: "People typically look at what is being talked about. So if I talk about the window, you'll probably automatically look at the window. So we can measure what people look at as they listen to sentences to get a sense of what they think the sentence is about at any given time."

Snedeker's thesis was that we actually don't know what part of language comprehension this paradigm measures. Does it measure your interpretation of individual words or of the sentence as a whole? One of the things about language is that words have meanings by themselves, but when combined into sentences, new meanings arise that aren't part of any individual word. So "book" is a physical object, but if I say "The author started the book", you likely interpret "book" as something closer to an activity ("writing the book") than a physical object.

Because the Visual World Paradigm is used extensively by sentence-comprehension people (like me), we hope that it measures sentence comprehension, not just individual words. Snedeker walked through many of the classic results from the Visual World Paradigm and argued that they are consistent with the possibility that the Visual World Paradigm just measures word meaning, not sentence meaning.

She then presented a project showing that, at least in some cases, the Visual World Paradigm is sensitive to sentence meaning, which she did by looking at negation. In "John broke the plate", we are talking about a broken plate, where as in "John didn't break the plate", we are not. So negation completely changes the meaning of the sentence. She told participants stories about different objects while the participants looked at pictures of those objects on a computer screen (the screen of an automatic eyetracker, which can tell where the participant is looking). For example, the story might be about a clumsy child who was carrying dishes around and broke some of them but not others (and so, on the screen, there was a picture of a broken plate and a picture of a not-broken plate). She found that adults and even children as young as three years old look at the broken plate when they heard "John broke the plate" but at the not-broken plate when they heard "John didn't break the plate", and they did so very quickly ... which is what you would expect if eyetracking was measuring your current interpretation of the sentence rather than just your current interpretation of the individual words (in which case, when you hear the word "plate", either plate will do).

(This work was joint work with Miseon Lee -- a collaborator of mine -- Tracy Brookhyser and Matthew Jiang.)

The First Mention Effect

W. Quin Yow of Singapore University of Technology and Design presented a project looking at pronoun interpretation (a topic close to my heart). She looked at sentences in which adults typically interpret the pronoun as referring to the previous subject (these are not the so-called "implicit causality" sentences I discuss most on this blog):
Miss Owl is going out with Miss Ducky. She wants her bag. 
She found, as usual, a strong preference for "she" to refer to Miss Owl in this (and similar) sentences. There is one older study that did not find such a preference in children roughly 4-6 years old, but several other studies have found evidence of (weak) first-mention effects in such sentences, including [shameless self-plug] work I presented at BUCLD two years ago.

Yow compared monolingual English-speaking four year-olds and bilingual English-speaking four year-olds (their "other" language differed from kid to kid). While only the bilinguals showed a statistically significant first-mention effect, the monolingual kids were only just barely not above chance and almost identical to the monolinguals. While the first-mention effects she saw were weaker than what I saw in my own work, her kids were slightly younger (four year-olds instead of five year-olds).

The additional twist she added was that, in some conditions, the experimenter pointed to one of the characters in the story at the moment she uttered the pronoun. This had a strong effect on how adults and bilingual children interpreted the pronoun; the effect was weaker or monolingual children, but I couldn't tell whether it was significantly weaker (with only 16 kids per group, a certain amount of variability between groups is expected).

In general, I interpret this as more evidence that young children do have (weak) first-mention biases. And it is nice to have one's results replicated.

Iconicity in sign language

Rachel Magid, a student of Jennie Pyers at Wellesley College, presented work on children's acquisition of sign language. Some signs are "iconic" in that they resemble the thing being referred to: for instance, miming swinging a hammer as the sign for "hammer" (I remember this example from the talk, but I do not remember whether that's an actual sign in ASL or any other sign language). Spoken languages have iconic words as well, such as "bark", which both means and sort of sounds like the sound a dog makes. This brings up an important point: iconic words/signs resemble the things they refer to, but not perfectly, and in fact it is often difficult to guess what they refer to, though once it has been explained to you, the relationship is obvious.

The big result was that four year-olds hearing children found it easier to learn iconic than non-iconic signs, whereas three year-olds did not. Similar results were found for deaf children (though if memory serves, the three year-old deaf children were trending towards doing better with iconic signs, though the number of subjects -- 9 deaf three year-olds -- was too small to say much about it).

Why care? There are those who think that early sign language acquisition -- and presumably the creation of sign languages themselves -- derives from imitation and mimicry (basically, sign languages and sign language acquisition start as a game of charades). If so, then you would expect those signs that are most related to imitation/mimicry to be the easiest to learn. However, the youngest children -- even deaf children who have learned a fair amount of sign language -- don't find them especially easy to learn. Why older children and adults *do* find them easier to learn still requires an explanation, though .

[Note: This is my interpretation of the work. Whether Magid and Pyers would endorse the last paragraph, I am not sure.]


Daniele Panizza (another occasional collaborator of mine) presented work done with a number of folks, including Stephen Crain, on 3-5 year-olds' interpretations of numbers. The question is whether young children understand reversals of entailment scales. So, if you say "John has two butterflies", that means that you do not have three, whereas saying "If John has two butterflies, give him a sticker" means that if he has two OR MORE butterflies, give him a sticker [NOTE, even adults find this "at least two" reading to be a bit iffy; the phenomenon is that they find the "at least two" reading much better in a downward-entailing context like a conditional MUCH BETTER than in a normal declarative]. Interestingly, another colleague and I had spent a good part of the last week wondering whether children that age understood this, so we were happy to learn the answer so quickly: they do.

In the next talk, Einat Shetreet presented work with Julia Reading, Nadine Gaab and Gennaro Chierchia also looking at entailment scales, but with scalar quantifiers rather than numerals. Adults generally think "John ate some of the cookies" means that he did not eat all of them (some = some but not all), whereas "John didn't eat all of the cookies" means that he ate some of them (not all = some). They found that six year olds also get both of these inferences, which is consistent with the just-mentioned Panizza study.

These studies may seem esoteric but get at recent theories of scalar implicature. Basically, theories of scalar implicature have been getting much more complex recently, suggesting that this relatively simple phenomenon involves many moving pieces. Interestingly, children are very bad at scalar implicature (even up through the early elementary years, children are much less likely to treat "some" as meaning "some but not all", so they'll accept sentences like "Some elephants have trunks" as reasonable sentences, whereas adults tend to find such sentences quite odd). So the race is on to figure out which of the many component parts of scalar implicature are the limiting step in early language acquisition.

There were many other good talks on the first day; these merely represent those for which I have the most extensive notes. 

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